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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
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   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
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   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


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#ifdef USE_PRAGMA_IMPLEMENTATION
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#pragma implementation				// gcc: Class implementation
#endif
#include "mysql_priv.h"
#include <m_ctype.h>
#include "my_dir.h"
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#include "sp_rcontext.h"
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#include "sp_head.h"
#include "sql_trigger.h"
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#include "sql_select.h"
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static void mark_as_dependent(THD *thd,
			      SELECT_LEX *last, SELECT_LEX *current,
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			      Item_ident *item);

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const String my_null_string("NULL", 4, default_charset_info);

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/****************************************************************************/

/* Hybrid_type_traits {_real} */

void Hybrid_type_traits::fix_length_and_dec(Item *item, Item *arg) const
{
  item->decimals= NOT_FIXED_DEC;
  item->max_length= item->float_length(arg->decimals);
}

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static const Hybrid_type_traits real_traits_instance;
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const Hybrid_type_traits *Hybrid_type_traits::instance()
{
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  return &real_traits_instance;
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}


my_decimal *
Hybrid_type_traits::val_decimal(Hybrid_type *val, my_decimal *to) const
{
  double2my_decimal(E_DEC_FATAL_ERROR, val->real, val->dec_buf);
  return val->dec_buf;
}


String *
Hybrid_type_traits::val_str(Hybrid_type *val, String *to, uint8 decimals) const
{
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  to->set_real(val->real, decimals, &my_charset_bin);
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  return to;
}

/* Hybrid_type_traits_decimal */
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static const Hybrid_type_traits_decimal decimal_traits_instance;
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const Hybrid_type_traits_decimal *Hybrid_type_traits_decimal::instance()
{
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  return &decimal_traits_instance;
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}


void
Hybrid_type_traits_decimal::fix_length_and_dec(Item *item, Item *arg) const
{
  item->decimals= arg->decimals;
  item->max_length= min(arg->max_length + DECIMAL_LONGLONG_DIGITS,
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                        DECIMAL_MAX_STR_LENGTH);
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}


void Hybrid_type_traits_decimal::set_zero(Hybrid_type *val) const
{
  my_decimal_set_zero(&val->dec_buf[0]);
  val->used_dec_buf_no= 0;
}


void Hybrid_type_traits_decimal::add(Hybrid_type *val, Field *f) const
{
  my_decimal_add(E_DEC_FATAL_ERROR,
                 &val->dec_buf[val->used_dec_buf_no ^ 1],
                 &val->dec_buf[val->used_dec_buf_no],
                 f->val_decimal(&val->dec_buf[2]));
  val->used_dec_buf_no^= 1;
}


void Hybrid_type_traits_decimal::div(Hybrid_type *val, ulonglong u) const
{
  int2my_decimal(E_DEC_FATAL_ERROR, u, TRUE, &val->dec_buf[2]);
  /* XXX: what is '4' for scale? */
  my_decimal_div(E_DEC_FATAL_ERROR,
                 &val->dec_buf[val->used_dec_buf_no ^ 1],
                 &val->dec_buf[val->used_dec_buf_no],
                 &val->dec_buf[2], 4);
  val->used_dec_buf_no^= 1;
}


longlong
Hybrid_type_traits_decimal::val_int(Hybrid_type *val, bool unsigned_flag) const
{
  longlong result;
  my_decimal2int(E_DEC_FATAL_ERROR, &val->dec_buf[val->used_dec_buf_no],
                 unsigned_flag, &result);
  return result;
}


double
Hybrid_type_traits_decimal::val_real(Hybrid_type *val) const
{
  my_decimal2double(E_DEC_FATAL_ERROR, &val->dec_buf[val->used_dec_buf_no],
                    &val->real);
  return val->real;
}


String *
Hybrid_type_traits_decimal::val_str(Hybrid_type *val, String *to,
                                    uint8 decimals) const
{
  my_decimal_round(E_DEC_FATAL_ERROR, &val->dec_buf[val->used_dec_buf_no],
                   decimals, FALSE, &val->dec_buf[2]);
  my_decimal2string(E_DEC_FATAL_ERROR, &val->dec_buf[2], 0, 0, 0, to);
  return to;
}

/* Hybrid_type_traits_integer */
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static const Hybrid_type_traits_integer integer_traits_instance;
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const Hybrid_type_traits_integer *Hybrid_type_traits_integer::instance()
{
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  return &integer_traits_instance;
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}

void
Hybrid_type_traits_integer::fix_length_and_dec(Item *item, Item *arg) const
{
  item->decimals= 0;
  item->max_length= 21;
  item->unsigned_flag= 0;
}

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/*****************************************************************************
** Item functions
*****************************************************************************/

/* Init all special items */

void item_init(void)
{
  item_user_lock_init();
}

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/*
TODO: make this functions class dependent
*/
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bool Item::val_bool()
{
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  switch(result_type()) {
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  case INT_RESULT:
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    return val_int() != 0;
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  case DECIMAL_RESULT:
  {
    my_decimal decimal_value;
    my_decimal *val= val_decimal(&decimal_value);
    if (val)
      return !my_decimal_is_zero(val);
    return 0;
  }
  case REAL_RESULT:
  case STRING_RESULT:
    return val_real() != 0.0;
  case ROW_RESULT:
  default:
    DBUG_ASSERT(0);
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    return 0;                                   // Wrong (but safe)
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  }
}


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String *Item::val_string_from_real(String *str)
{
  double nr= val_real();
  if (null_value)
    return 0;					/* purecov: inspected */
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  str->set_real(nr,decimals, &my_charset_bin);
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  return str;
}


String *Item::val_string_from_int(String *str)
{
  longlong nr= val_int();
  if (null_value)
    return 0;
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  str->set_int(nr, unsigned_flag, &my_charset_bin);
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  return str;
}


String *Item::val_string_from_decimal(String *str)
{
  my_decimal dec_buf, *dec= val_decimal(&dec_buf);
  if (null_value)
    return 0;
  my_decimal_round(E_DEC_FATAL_ERROR, dec, decimals, FALSE, &dec_buf);
  my_decimal2string(E_DEC_FATAL_ERROR, &dec_buf, 0, 0, 0, str);
  return str;
}


my_decimal *Item::val_decimal_from_real(my_decimal *decimal_value)
{
  double nr= val_real();
  if (null_value)
    return 0;
  double2my_decimal(E_DEC_FATAL_ERROR, nr, decimal_value);
  return (decimal_value);
}


my_decimal *Item::val_decimal_from_int(my_decimal *decimal_value)
{
  longlong nr= val_int();
  if (null_value)
    return 0;
  int2my_decimal(E_DEC_FATAL_ERROR, nr, unsigned_flag, decimal_value);
  return decimal_value;
}


my_decimal *Item::val_decimal_from_string(my_decimal *decimal_value)
{
  String *res;
  char *end_ptr;
  if (!(res= val_str(&str_value)))
    return 0;                                   // NULL or EOM

  end_ptr= (char*) res->ptr()+ res->length();
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  if (str2my_decimal(E_DEC_FATAL_ERROR & ~E_DEC_BAD_NUM,
                     res->ptr(), res->length(), res->charset(),
                     decimal_value) & E_DEC_BAD_NUM)
  {
    push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                        ER_TRUNCATED_WRONG_VALUE,
                        ER(ER_TRUNCATED_WRONG_VALUE), "DECIMAL",
                        str_value.c_ptr());
  }
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  return decimal_value;
}


double Item::val_real_from_decimal()
{
  /* Note that fix_fields may not be called for Item_avg_field items */
  double result;
  my_decimal value_buff, *dec_val= val_decimal(&value_buff);
  if (null_value)
    return 0.0;
  my_decimal2double(E_DEC_FATAL_ERROR, dec_val, &result);
  return result;
}


longlong Item::val_int_from_decimal()
{
  /* Note that fix_fields may not be called for Item_avg_field items */
  longlong result;
  my_decimal value, *dec_val= val_decimal(&value);
  if (null_value)
    return 0;
  my_decimal2int(E_DEC_FATAL_ERROR, dec_val, unsigned_flag, &result);
  return result;
}


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Item::Item():
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  rsize(0), name(0), orig_name(0), name_length(0), fixed(0),
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  is_autogenerated_name(TRUE),
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  collation(&my_charset_bin, DERIVATION_COERCIBLE)
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{
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  marker= 0;
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  maybe_null=null_value=with_sum_func=unsigned_flag=0;
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  decimals= 0; max_length= 0;
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  with_subselect= 0;
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  /* Put item in free list so that we can free all items at end */
  THD *thd= current_thd;
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  next= thd->free_list;
  thd->free_list= this;
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  /*
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    Item constructor can be called during execution other then SQL_COM
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    command => we should check thd->lex->current_select on zero (thd->lex
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    can be uninitialised)
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  */
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  if (thd->lex->current_select)
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  {
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    enum_parsing_place place= 
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      thd->lex->current_select->parsing_place;
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    if (place == SELECT_LIST ||
	place == IN_HAVING)
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      thd->lex->current_select->select_n_having_items++;
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  }
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}

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/*
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  Constructor used by Item_field, Item_*_ref & aggregate (sum) functions.
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  Used for duplicating lists in processing queries with temporary
  tables
*/
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Item::Item(THD *thd, Item *item):
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  rsize(0),
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  str_value(item->str_value),
  name(item->name),
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  orig_name(item->orig_name),
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  max_length(item->max_length),
  marker(item->marker),
  decimals(item->decimals),
  maybe_null(item->maybe_null),
  null_value(item->null_value),
  unsigned_flag(item->unsigned_flag),
  with_sum_func(item->with_sum_func),
  fixed(item->fixed),
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  collation(item->collation)
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{
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  next= thd->free_list;				// Put in free list
  thd->free_list= this;
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}

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uint Item::decimal_precision() const
{
  Item_result restype= result_type();

  if ((restype == DECIMAL_RESULT) || (restype == INT_RESULT))
    return min(my_decimal_length_to_precision(max_length, decimals, unsigned_flag),
               DECIMAL_MAX_PRECISION);
  return min(max_length, DECIMAL_MAX_PRECISION);
}


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void Item::print_item_w_name(String *str)
{
  print(str);
  if (name)
  {
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    THD *thd= current_thd;
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    str->append(STRING_WITH_LEN(" AS "));
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    append_identifier(thd, str, name, (uint) strlen(name));
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  }
}


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void Item::cleanup()
{
  DBUG_ENTER("Item::cleanup");
  fixed=0;
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  marker= 0;
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  if (orig_name)
    name= orig_name;
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  DBUG_VOID_RETURN;
}

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/*
  cleanup() item if it is 'fixed'

  SYNOPSIS
    cleanup_processor()
    arg - a dummy parameter, is not used here
*/

bool Item::cleanup_processor(byte *arg)
{
  if (fixed)
    cleanup();
  return FALSE;
}


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/*
  rename item (used for views, cleanup() return original name)

  SYNOPSIS
    Item::rename()
    new_name	new name of item;
*/

void Item::rename(char *new_name)
{
  /*
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    we can compare pointers to names here, because if name was not changed,
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    pointer will be same
  */
  if (!orig_name && new_name != name)
    orig_name= name;
  name= new_name;
}


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/*
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  Traverse item tree possibly transforming it (replacing items).
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  SYNOPSIS
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    Item::transform()
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      transformer    functor that performs transformation of a subtree
      arg            opaque argument passed to the functor

  DESCRIPTION
    This function is designed to ease transformation of Item trees.

    Re-execution note: every such transformation is registered for
    rollback by THD::change_item_tree() and is rolled back at the end
    of execution by THD::rollback_item_tree_changes().

    Therefore:

      - this function can not be used at prepared statement prepare
        (in particular, in fix_fields!), as only permanent
        transformation of Item trees are allowed at prepare.

      - the transformer function shall allocate new Items in execution
        memory root (thd->mem_root) and not anywhere else: allocated
        items will be gone in the end of execution.

    If you don't need to transform an item tree, but only traverse
    it, please use Item::walk() instead.


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  RETURN VALUE
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    Returns pointer to the new subtree root.  THD::change_item_tree()
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    should be called for it if transformation took place, i.e. if a
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    pointer to newly allocated item is returned.
*/

Item* Item::transform(Item_transformer transformer, byte *arg)
{
  DBUG_ASSERT(!current_thd->is_stmt_prepare());

  return (this->*transformer)(arg);
}


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Item_ident::Item_ident(Name_resolution_context *context_arg,
                       const char *db_name_arg,const char *table_name_arg,
		       const char *field_name_arg)
  :orig_db_name(db_name_arg), orig_table_name(table_name_arg),
   orig_field_name(field_name_arg), context(context_arg),
   db_name(db_name_arg), table_name(table_name_arg),
   field_name(field_name_arg),
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   alias_name_used(FALSE), cached_field_index(NO_CACHED_FIELD_INDEX),
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   cached_table(0), depended_from(0)
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{
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  name = (char*) field_name_arg;
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}

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/* Constructor used by Item_field & Item_*_ref (see Item comment) */
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Item_ident::Item_ident(THD *thd, Item_ident *item)
  :Item(thd, item),
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   orig_db_name(item->orig_db_name),
   orig_table_name(item->orig_table_name), 
   orig_field_name(item->orig_field_name),
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   context(item->context),
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   db_name(item->db_name),
   table_name(item->table_name),
   field_name(item->field_name),
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   alias_name_used(item->alias_name_used),
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   cached_field_index(item->cached_field_index),
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   cached_table(item->cached_table),
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   depended_from(item->depended_from)
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{}
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void Item_ident::cleanup()
{
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  DBUG_ENTER("Item_ident::cleanup");
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#ifdef CANT_BE_USED_AS_MEMORY_IS_FREED
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		       db_name ? db_name : "(null)",
                       orig_db_name ? orig_db_name : "(null)",
		       table_name ? table_name : "(null)",
                       orig_table_name ? orig_table_name : "(null)",
		       field_name ? field_name : "(null)",
                       orig_field_name ? orig_field_name : "(null)"));
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#endif
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  Item::cleanup();
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  db_name= orig_db_name; 
  table_name= orig_table_name;
  field_name= orig_field_name;
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  depended_from= 0;
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  DBUG_VOID_RETURN;
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}

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bool Item_ident::remove_dependence_processor(byte * arg)
{
  DBUG_ENTER("Item_ident::remove_dependence_processor");
  if (depended_from == (st_select_lex *) arg)
    depended_from= 0;
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  DBUG_RETURN(0);
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}


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/*
  Store the pointer to this item field into a list if not already there.

  SYNOPSIS
    Item_field::collect_item_field_processor()
    arg  pointer to a List<Item_field>

  DESCRIPTION
    The method is used by Item::walk to collect all unique Item_field objects
    from a tree of Items into a set of items represented as a list.

  IMPLEMENTATION
    Item_cond::walk() and Item_func::walk() stop the evaluation of the
    processor function for its arguments once the processor returns
    true.Therefore in order to force this method being called for all item
    arguments in a condition the method must return false.

  RETURN
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    FALSE to force the evaluation of collect_item_field_processor
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          for the subsequent items.
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*/

bool Item_field::collect_item_field_processor(byte *arg)
{
  DBUG_ENTER("Item_field::collect_item_field_processor");
  DBUG_PRINT("info", ("%s", field->field_name ? field->field_name : "noname"));
  List<Item_field> *item_list= (List<Item_field>*) arg;
  List_iterator<Item_field> item_list_it(*item_list);
  Item_field *curr_item;
  while ((curr_item= item_list_it++))
  {
    if (curr_item->eq(this, 1))
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      DBUG_RETURN(FALSE); /* Already in the set. */
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  }
  item_list->push_back(this);
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  DBUG_RETURN(FALSE);
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}


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/*
  Check if an Item_field references some field from a list of fields.

  SYNOPSIS
    Item_field::find_item_in_field_list_processor
    arg   Field being compared, arg must be of type Field

  DESCRIPTION
    Check whether the Item_field represented by 'this' references any
    of the fields in the keyparts passed via 'arg'. Used with the
    method Item::walk() to test whether any keypart in a sequence of
    keyparts is referenced in an expression.

  RETURN
    TRUE  if 'this' references the field 'arg'
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    FALSE otherwise
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*/
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bool Item_field::find_item_in_field_list_processor(byte *arg)
{
  KEY_PART_INFO *first_non_group_part= *((KEY_PART_INFO **) arg);
  KEY_PART_INFO *last_part= *(((KEY_PART_INFO **) arg) + 1);
  KEY_PART_INFO *cur_part;

  for (cur_part= first_non_group_part; cur_part != last_part; cur_part++)
  {
    if (field->eq(cur_part->field))
      return TRUE;
  }
  return FALSE;
}


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/*
  Mark field in read_map

  NOTES
    This is used by filesort to register used fields in a a temporary
    column read set or to register used fields in a view
*/

bool Item_field::register_field_in_read_map(byte *arg)
{
  TABLE *table= (TABLE *) arg;
  if (field->table == table || !table)
    bitmap_set_bit(field->table->read_set, field->field_index);
  return 0;
}


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bool Item::check_cols(uint c)
{
  if (c != 1)
  {
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    my_error(ER_OPERAND_COLUMNS, MYF(0), c);
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    return 1;
  }
  return 0;
}

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void Item::set_name(const char *str, uint length, CHARSET_INFO *cs)
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{
  if (!length)
  {
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    /* Empty string, used by AS or internal function like last_insert_id() */
    name= (char*) str;
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    name_length= 0;
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    return;
  }
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  if (cs->ctype)
  {
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    uint orig_len= length;
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    /*
      This will probably need a better implementation in the future:
      a function in CHARSET_INFO structure.
    */
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    while (length && !my_isgraph(cs,*str))
    {						// Fix problem with yacc
      length--;
      str++;
    }
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    if (orig_len != length && !is_autogenerated_name)
      push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                          ER_REMOVED_SPACES, ER(ER_REMOVED_SPACES),
                          str + length - orig_len);

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  }
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  if (!my_charset_same(cs, system_charset_info))
  {
    uint32 res_length;
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    name= sql_strmake_with_convert(str, name_length= length, cs,
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				   MAX_ALIAS_NAME, system_charset_info,
				   &res_length);
  }
  else
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    name= sql_strmake(str, (name_length= min(length,MAX_ALIAS_NAME)));
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}

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/*
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  This function is called when:
  - Comparing items in the WHERE clause (when doing where optimization)
  - When trying to find an ORDER BY/GROUP BY item in the SELECT part
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*/

bool Item::eq(const Item *item, bool binary_cmp) const
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{
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  /*
    Note, that this is never TRUE if item is a Item_param:
    for all basic constants we have special checks, and Item_param's
    type() can be only among basic constant types.
  */
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  return type() == item->type() && name && item->name &&
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    !my_strcasecmp(system_charset_info,name,item->name);
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}

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Item *Item::safe_charset_converter(CHARSET_INFO *tocs)
{
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  Item_func_conv_charset *conv= new Item_func_conv_charset(this, tocs, 1);
  return conv->safe ? conv : NULL;
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}


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/*
  Created mostly for mysql_prepare_table(). Important
  when a string ENUM/SET column is described with a numeric default value:

  CREATE TABLE t1(a SET('a') DEFAULT 1);

  We cannot use generic Item::safe_charset_converter(), because
  the latter returns a non-fixed Item, so val_str() crashes afterwards.
  Override Item_num method, to return a fixed item.
*/
Item *Item_num::safe_charset_converter(CHARSET_INFO *tocs)
{
  Item_string *conv;
  char buf[64];
  String *s, tmp(buf, sizeof(buf), &my_charset_bin);
  s= val_str(&tmp);
  if ((conv= new Item_string(s->ptr(), s->length(), s->charset())))
  {
    conv->str_value.copy();
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    conv->str_value.mark_as_const();
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  }
  return conv;
}


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Item *Item_static_float_func::safe_charset_converter(CHARSET_INFO *tocs)
{
  Item_string *conv;
  char buf[64];
  String *s, tmp(buf, sizeof(buf), &my_charset_bin);
  s= val_str(&tmp);
  if ((conv= new Item_static_string_func(func_name, s->ptr(), s->length(),
                                         s->charset())))
  {
    conv->str_value.copy();
    conv->str_value.mark_as_const();
  }
  return conv;
}


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Item *Item_string::safe_charset_converter(CHARSET_INFO *tocs)
{
  Item_string *conv;
  uint conv_errors;
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  char *ptr;
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  String tmp, cstr, *ostr= val_str(&tmp);
  cstr.copy(ostr->ptr(), ostr->length(), ostr->charset(), tocs, &conv_errors);
  if (conv_errors || !(conv= new Item_string(cstr.ptr(), cstr.length(),
                                             cstr.charset(),
                                             collation.derivation)))
  {
    /*
      Safe conversion is not possible (or EOM).
      We could not convert a string into the requested character set
      without data loss. The target charset does not cover all the
      characters from the string. Operation cannot be done correctly.
    */
    return NULL;
  }
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  if (!(ptr= current_thd->memdup(cstr.ptr(), cstr.length() + 1 )))
    return NULL;
  conv->str_value.set(ptr, cstr.length(), cstr.charset());
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  /* Ensure that no one is going to change the result string */
  conv->str_value.mark_as_const();
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  return conv;
}


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Item *Item_param::safe_charset_converter(CHARSET_INFO *tocs)
{
  if (const_item())
  {
    uint cnv_errors;
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    String *ostr= val_str(&cnvstr);
    cnvitem->str_value.copy(ostr->ptr(), ostr->length(),
                            ostr->charset(), tocs, &cnv_errors);
    if (cnv_errors)
       return NULL;
    cnvitem->str_value.mark_as_const();
    cnvitem->max_length= cnvitem->str_value.numchars() * tocs->mbmaxlen;
    return cnvitem;
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  }
  return NULL;
}


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Item *Item_static_string_func::safe_charset_converter(CHARSET_INFO *tocs)
{
  Item_string *conv;
  uint conv_errors;
  String tmp, cstr, *ostr= val_str(&tmp);
  cstr.copy(ostr->ptr(), ostr->length(), ostr->charset(), tocs, &conv_errors);
  if (conv_errors ||
      !(conv= new Item_static_string_func(func_name,
                                          cstr.ptr(), cstr.length(),
                                          cstr.charset(),
                                          collation.derivation)))
  {
    /*
      Safe conversion is not possible (or EOM).
      We could not convert a string into the requested character set
      without data loss. The target charset does not cover all the
      characters from the string. Operation cannot be done correctly.
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    */
    return NULL;
  }
  conv->str_value.copy();
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  /* Ensure that no one is going to change the result string */
  conv->str_value.mark_as_const();
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  return conv;
}


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bool Item_string::eq(const Item *item, bool binary_cmp) const
{
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  if (type() == item->type() && item->basic_const_item())
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  {
    if (binary_cmp)
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      return !stringcmp(&str_value, &item->str_value);
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    return (collation.collation == item->collation.collation &&
	    !sortcmp(&str_value, &item->str_value, collation.collation));
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  }
  return 0;
}


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/*
  Get the value of the function as a TIME structure.
  As a extra convenience the time structure is reset on error!
 */

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bool Item::get_date(TIME *ltime,uint fuzzydate)
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{
  char buff[40];
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  String tmp(buff,sizeof(buff), &my_charset_bin),*res;
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  if (!(res=val_str(&tmp)) ||
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      str_to_datetime_with_warn(res->ptr(), res->length(),
                                ltime, fuzzydate) <= MYSQL_TIMESTAMP_ERROR)
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  {
    bzero((char*) ltime,sizeof(*ltime));
    return 1;
  }
  return 0;
}

/*
  Get time of first argument.
  As a extra convenience the time structure is reset on error!
 */

bool Item::get_time(TIME *ltime)
{
  char buff[40];
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  String tmp(buff,sizeof(buff),&my_charset_bin),*res;
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  if (!(res=val_str(&tmp)) ||
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      str_to_time_with_warn(res->ptr(), res->length(), ltime))
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  {
    bzero((char*) ltime,sizeof(*ltime));
    return 1;
  }
  return 0;
}

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CHARSET_INFO *Item::default_charset()
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{
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  return current_thd->variables.collation_connection;
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}

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/*
  Save value in field, but don't give any warnings

  NOTES
   This is used to temporary store and retrieve a value in a column,
   for example in opt_range to adjust the key value to fit the column.
*/

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int Item::save_in_field_no_warnings(Field *field, bool no_conversions)
{
  int res;
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  TABLE *table= field->table;
  THD *thd= table->in_use;
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  enum_check_fields tmp= thd->count_cuted_fields;
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  my_bitmap_map *old_map= dbug_tmp_use_all_columns(table, table->write_set);
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  thd->count_cuted_fields= CHECK_FIELD_IGNORE;
  res= save_in_field(field, no_conversions);
  thd->count_cuted_fields= tmp;
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  dbug_tmp_restore_column_map(table->write_set, old_map);
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  return res;
}


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/*****************************************************************************
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  Item_sp_variable methods
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*****************************************************************************/
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Item_sp_variable::Item_sp_variable(char *sp_var_name_str,
                                   uint sp_var_name_length)
  :m_thd(0)
#ifndef DBUG_OFF
   , m_sp(0)
#endif
{
  m_name.str= sp_var_name_str;
  m_name.length= sp_var_name_length;
}


bool Item_sp_variable::fix_fields(THD *thd, Item **)
{
  Item *it;

  m_thd= thd; /* NOTE: this must be set before any this_xxx() */
  it= this_item();

  DBUG_ASSERT(it->fixed);

  max_length= it->max_length;
  decimals= it->decimals;
  unsigned_flag= it->unsigned_flag;
  fixed= 1;
  collation.set(it->collation.collation, it->collation.derivation);

  return FALSE;
}


double Item_sp_variable::val_real()
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{
  DBUG_ASSERT(fixed);
  Item *it= this_item();
  double ret= it->val_real();
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  null_value= it->null_value;
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  return ret;
}


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longlong Item_sp_variable::val_int()
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{
  DBUG_ASSERT(fixed);
  Item *it= this_item();
  longlong ret= it->val_int();
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  null_value= it->null_value;
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  return ret;
}


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String *Item_sp_variable::val_str(String *sp)
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{
  DBUG_ASSERT(fixed);
  Item *it= this_item();
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  String *res= it->val_str(sp);
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  null_value= it->null_value;
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  if (!res)
    return NULL;

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  /*
    This way we mark returned value of val_str as const,
    so that various functions (e.g. CONCAT) won't try to
    modify the value of the Item. Analogous mechanism is
    implemented for Item_param.
    Without this trick Item_splocal could be changed as a
    side-effect of expression computation. Here is an example
    of what happens without it: suppose x is varchar local
    variable in a SP with initial value 'ab' Then
      select concat(x,'c');
    would change x's value to 'abc', as Item_func_concat::val_str()
    would use x's internal buffer to compute the result.
    This is intended behaviour of Item_func_concat. Comments to
    Item_param class contain some more details on the topic.
  */
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  if (res != &str_value)
    str_value.set(res->ptr(), res->length(), res->charset());
  else
    res->mark_as_const();
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  return &str_value;
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}


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my_decimal *Item_sp_variable::val_decimal(my_decimal *decimal_value)
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{
  DBUG_ASSERT(fixed);
  Item *it= this_item();
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  my_decimal *val= it->val_decimal(decimal_value);
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  null_value= it->null_value;
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  return val;
}


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bool Item_sp_variable::is_null()
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{
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  return this_item()->is_null();
}


/*****************************************************************************
  Item_splocal methods
*****************************************************************************/

Item_splocal::Item_splocal(const LEX_STRING &sp_var_name,
                           uint sp_var_idx,
                           enum_field_types sp_var_type,
                           uint pos_in_q)
  :Item_sp_variable(sp_var_name.str, sp_var_name.length),
   m_var_idx(sp_var_idx), pos_in_query(pos_in_q)
{
  maybe_null= TRUE;

  m_type= sp_map_item_type(sp_var_type);
  m_result_type= sp_map_result_type(sp_var_type);
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}


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Item *
Item_splocal::this_item()
{
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  DBUG_ASSERT(m_sp == m_thd->spcont->sp);

  return m_thd->spcont->get_item(m_var_idx);
}

const Item *
Item_splocal::this_item() const
{
  DBUG_ASSERT(m_sp == m_thd->spcont->sp);

  return m_thd->spcont->get_item(m_var_idx);
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}

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Item **
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Item_splocal::this_item_addr(THD *thd, Item **)
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{
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  DBUG_ASSERT(m_sp == thd->spcont->sp);

  return thd->spcont->get_item_addr(m_var_idx);
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}

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void Item_splocal::print(String *str)
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{
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  str->reserve(m_name.length+8);
  str->append(m_name.str, m_name.length);
  str->append('@');
  str->qs_append(m_var_idx);
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}

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bool Item_splocal::set_value(THD *thd, sp_rcontext *ctx, Item **it)
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{
  return ctx->set_variable(thd, get_var_idx(), it);
}


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/*****************************************************************************
  Item_case_expr methods
*****************************************************************************/

Item_case_expr::Item_case_expr(int case_expr_id)
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  :Item_sp_variable( C_STRING_WITH_LEN("case_expr")),
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   m_case_expr_id(case_expr_id)
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{
}


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Item *
Item_case_expr::this_item()
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{
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  DBUG_ASSERT(m_sp == m_thd->spcont->sp);

  return m_thd->spcont->get_case_expr(m_case_expr_id);
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}


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const Item *
Item_case_expr::this_item() const
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{
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  DBUG_ASSERT(m_sp == m_thd->spcont->sp);

  return m_thd->spcont->get_case_expr(m_case_expr_id);
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}


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Item **
Item_case_expr::this_item_addr(THD *thd, Item **)
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{
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  DBUG_ASSERT(m_sp == thd->spcont->sp);

  return thd->spcont->get_case_expr_addr(m_case_expr_id);
}


void Item_case_expr::print(String *str)
{
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  VOID(str->append(STRING_WITH_LEN("case_expr@")));
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  str->qs_append(m_case_expr_id);
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}


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/*****************************************************************************
  Item_name_const methods
*****************************************************************************/
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double Item_name_const::val_real()
{
  DBUG_ASSERT(fixed);
  double ret= value_item->val_real();
  null_value= value_item->null_value;
  return ret;
}


longlong Item_name_const::val_int()
{
  DBUG_ASSERT(fixed);
  longlong ret= value_item->val_int();
  null_value= value_item->null_value;
  return ret;
}


String *Item_name_const::val_str(String *sp)
{
  DBUG_ASSERT(fixed);
  String *ret= value_item->val_str(sp);
  null_value= value_item->null_value;
  return ret;
}


my_decimal *Item_name_const::val_decimal(my_decimal *decimal_value)
{
  DBUG_ASSERT(fixed);
  my_decimal *val= value_item->val_decimal(decimal_value);
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  null_value= value_item->null_value;
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  return val;
}


bool Item_name_const::is_null()
{
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  return value_item->is_null();
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}

Item::Type Item_name_const::type() const
{
  return value_item->type();
}


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bool Item_name_const::fix_fields(THD *thd, Item **ref)
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{
  char buf[128];
  String *item_name;
  String s(buf, sizeof(buf), &my_charset_bin);
  s.length(0);

  if (value_item->fix_fields(thd, &value_item) ||
      name_item->fix_fields(thd, &name_item))
    return TRUE;
  if (!(value_item->const_item() && name_item->const_item()))
    return TRUE;

  if (!(item_name= name_item->val_str(&s)))
    return TRUE; /* Can't have a NULL name */

  set_name(item_name->ptr(), (uint) item_name->length(), system_charset_info);
  max_length= value_item->max_length;
  decimals= value_item->decimals;
  fixed= 1;
  return FALSE;
}


void Item_name_const::print(String *str)
{
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  str->append(STRING_WITH_LEN("NAME_CONST("));
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  name_item->print(str);
  str->append(',');
  value_item->print(str);
  str->append(')');
}

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/*
  Move SUM items out from item tree and replace with reference

  SYNOPSIS
    split_sum_func2()
    thd			Thread handler
    ref_pointer_array	Pointer to array of reference fields
    fields		All fields in select
    ref			Pointer to item
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    skip_registered     <=> function be must skipped for registered SUM items
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  NOTES
   This is from split_sum_func2() for items that should be split

   All found SUM items are added FIRST in the fields list and
   we replace the item with a reference.

   thd->fatal_error() may be called if we are out of memory
*/


void Item::split_sum_func2(THD *thd, Item **ref_pointer_array,
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                           List<Item> &fields, Item **ref, 
                           bool skip_registered)
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{
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  /* An item of type Item_sum  is registered <=> ref_by != 0 */ 
  if (type() == SUM_FUNC_ITEM && skip_registered && 
      ((Item_sum *) this)->ref_by)
    return;                                                 
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  if (type() != SUM_FUNC_ITEM && with_sum_func)
  {
    /* Will split complicated items and ignore simple ones */
    split_sum_func(thd, ref_pointer_array, fields);
  }
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  else if ((type() == SUM_FUNC_ITEM || (used_tables() & ~PARAM_TABLE_BIT)) &&
           (type() != REF_ITEM ||
           ((Item_ref*)this)->ref_type() == Item_ref::VIEW_REF))
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  {
    /*
      Replace item with a reference so that we can easily calculate
      it (in case of sum functions) or copy it (in case of fields)

      The test above is to ensure we don't do a reference for things
      that are constants (PARAM_TABLE_BIT is in effect a constant)
      or already referenced (for example an item in HAVING)
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      Exception is Item_direct_view_ref which we need to convert to
      Item_ref to allow fields from view being stored in tmp table.
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    */
    uint el= fields.elements;
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    Item *new_item, *real_itm= real_item();
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    ref_pointer_array[el]= real_itm;
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    if (!(new_item= new Item_ref(&thd->lex->current_select->context,
                                 ref_pointer_array + el, 0, name)))
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      return;                                   // fatal_error is set
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    fields.push_front(real_itm);
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    thd->change_item_tree(ref, new_item);
  }
}


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/*
   Aggregate two collations together taking
   into account their coercibility (aka derivation):

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   0 == DERIVATION_EXPLICIT  - an explicitly written COLLATE clause
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   1 == DERIVATION_NONE      - a mix of two different collations
   2 == DERIVATION_IMPLICIT  - a column
   3 == DERIVATION_COERCIBLE - a string constant

   The most important rules are:

   1. If collations are the same:
      chose this collation, and the strongest derivation.

   2. If collations are different:
     - Character sets may differ, but only if conversion without
       data loss is possible. The caller provides flags whether
       character set conversion attempts should be done. If no
       flags are substituted, then the character sets must be the same.
       Currently processed flags are:
         MY_COLL_ALLOW_SUPERSET_CONV  - allow conversion to a superset
         MY_COLL_ALLOW_COERCIBLE_CONV - allow conversion of a coercible value
     - two EXPLICIT collations produce an error, e.g. this is wrong:
       CONCAT(expr1 collate latin1_swedish_ci, expr2 collate latin1_german_ci)
     - the side with smaller derivation value wins,
       i.e. a column is stronger than a string constant,
       an explicit COLLATE clause is stronger than a column.
     - if derivations are the same, we have DERIVATION_NONE,
       we'll wait for an explicit COLLATE clause which possibly can
       come from another argument later: for example, this is valid,
       but we don't know yet when collecting the first two arguments:
         CONCAT(latin1_swedish_ci_column,
                latin1_german1_ci_column,
                expr COLLATE latin1_german2_ci)
*/
bool DTCollation::aggregate(DTCollation &dt, uint flags)
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{
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  if (!my_charset_same(collation, dt.collation))
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  {
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    /* 
       We do allow to use binary strings (like BLOBS)
       together with character strings.
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       Binaries have more precedence than a character
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       string of the same derivation.
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    */
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    if (collation == &my_charset_bin)
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    {
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      if (derivation <= dt.derivation)
	; // Do nothing
      else
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      {
	set(dt); 
      }
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    }
1291
    else if (dt.collation == &my_charset_bin)
1292
    {
1293
      if (dt.derivation <= derivation)
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      {
1295
        set(dt);
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      }
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      else
       ; // Do nothing
1299
    }
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    else if ((flags & MY_COLL_ALLOW_SUPERSET_CONV) &&
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             collation->state & MY_CS_UNICODE &&
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             (derivation < dt.derivation ||
             (derivation == dt.derivation &&
             !(dt.collation->state & MY_CS_UNICODE))))
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    {
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      // Do nothing
    }
    else if ((flags & MY_COLL_ALLOW_SUPERSET_CONV) &&
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             dt.collation->state & MY_CS_UNICODE &&
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             (dt.derivation < derivation ||
              (dt.derivation == derivation &&
             !(collation->state & MY_CS_UNICODE))))
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    {
      set(dt);
    }
    else if ((flags & MY_COLL_ALLOW_COERCIBLE_CONV) &&
             derivation < dt.derivation &&
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             dt.derivation >= DERIVATION_SYSCONST)
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    {
      // Do nothing;
    }
    else if ((flags & MY_COLL_ALLOW_COERCIBLE_CONV) &&
             dt.derivation < derivation &&
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             derivation >= DERIVATION_SYSCONST)
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    {
      set(dt);
1327
    }
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    else
    {
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      // Cannot apply conversion
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      set(0, DERIVATION_NONE);
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      return 1;
1333
    }
1334
  }
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  else if (derivation < dt.derivation)
1336
  {
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    // Do nothing
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  }
1339
  else if (dt.derivation < derivation)
1340
  {
1341
    set(dt);
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  }
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  else
  { 
    if (collation == dt.collation)
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    {
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      // Do nothing
    }
    else 
    {
      if (derivation == DERIVATION_EXPLICIT)
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      {
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	set(0, DERIVATION_NONE);
	return 1;
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      }
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      if (collation->state & MY_CS_BINSORT)
        return 0;
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      if (dt.collation->state & MY_CS_BINSORT)
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      {
        set(dt);
        return 0;
      }
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      CHARSET_INFO *bin= get_charset_by_csname(collation->csname, 
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                                               MY_CS_BINSORT,MYF(0));
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      set(bin, DERIVATION_NONE);
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    }
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  }
  return 0;
}

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/******************************/
static
void my_coll_agg_error(DTCollation &c1, DTCollation &c2, const char *fname)
{
  my_error(ER_CANT_AGGREGATE_2COLLATIONS,MYF(0),
           c1.collation->name,c1.derivation_name(),
           c2.collation->name,c2.derivation_name(),
           fname);
}


static
void my_coll_agg_error(DTCollation &c1, DTCollation &c2, DTCollation &c3,
                       const char *fname)
{
  my_error(ER_CANT_AGGREGATE_3COLLATIONS,MYF(0),
  	   c1.collation->name,c1.derivation_name(),
	   c2.collation->name,c2.derivation_name(),
	   c3.collation->name,c3.derivation_name(),
	   fname);
}


static
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void my_coll_agg_error(Item** args, uint count, const char *fname,
                       int item_sep)
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{
  if (count == 2)
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    my_coll_agg_error(args[0]->collation, args[item_sep]->collation, fname);
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  else if (count == 3)
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    my_coll_agg_error(args[0]->collation, args[item_sep]->collation,
                      args[2*item_sep]->collation, fname);
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  else
    my_error(ER_CANT_AGGREGATE_NCOLLATIONS,MYF(0),fname);
}


bool agg_item_collations(DTCollation &c, const char *fname,
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                         Item **av, uint count, uint flags, int item_sep)
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{
  uint i;
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  Item **arg;
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  c.set(av[0]->collation);
1414
  for (i= 1, arg= &av[item_sep]; i < count; i++, arg++)
1415
  {
1416
    if (c.aggregate((*arg)->collation, flags))
1417
    {
1418
      my_coll_agg_error(av, count, fname, item_sep);
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      return TRUE;
    }
  }
  if ((flags & MY_COLL_DISALLOW_NONE) &&
      c.derivation == DERIVATION_NONE)
  {
1425
    my_coll_agg_error(av, count, fname, item_sep);
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    return TRUE;
  }
  return FALSE;
}


bool agg_item_collations_for_comparison(DTCollation &c, const char *fname,
                                        Item **av, uint count, uint flags)
{
  return (agg_item_collations(c, fname, av, count,
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                              flags | MY_COLL_DISALLOW_NONE, 1));
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}


/* 
  Collect arguments' character sets together.
  We allow to apply automatic character set conversion in some cases.
  The conditions when conversion is possible are:
  - arguments A and B have different charsets
  - A wins according to coercibility rules
    (i.e. a column is stronger than a string constant,
     an explicit COLLATE clause is stronger than a column)
  - character set of A is either superset for character set of B,
    or B is a string constant which can be converted into the
    character set of A without data loss.
    
  If all of the above is true, then it's possible to convert
  B into the character set of A, and then compare according
  to the collation of A.
  
  For functions with more than two arguments:

    collect(A,B,C) ::= collect(collect(A,B),C)
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  Since this function calls THD::change_item_tree() on the passed Item **
  pointers, it is necessary to pass the original Item **'s, not copies.
  Otherwise their values will not be properly restored (see BUG#20769).
  If the items are not consecutive (eg. args[2] and args[5]), use the
  item_sep argument, ie.

    agg_item_charsets(coll, fname, &args[2], 2, flags, 3)

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*/

bool agg_item_charsets(DTCollation &coll, const char *fname,
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                       Item **args, uint nargs, uint flags, int item_sep)
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{
  Item **arg, **last, *safe_args[2];
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  LINT_INIT(safe_args[0]);
  LINT_INIT(safe_args[1]);
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  if (agg_item_collations(coll, fname, args, nargs, flags, item_sep))
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    return TRUE;

  /*
    For better error reporting: save the first and the second argument.
    We need this only if the the number of args is 3 or 2:
    - for a longer argument list, "Illegal mix of collations"
      doesn't display each argument's characteristics.
    - if nargs is 1, then this error cannot happen.
  */
  if (nargs >=2 && nargs <= 3)
  {
    safe_args[0]= args[0];
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    safe_args[1]= args[item_sep];
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  }

  THD *thd= current_thd;
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  Query_arena *arena, backup;
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  bool res= FALSE;
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  uint i;
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  /*
    In case we're in statement prepare, create conversion item
    in its memory: it will be reused on each execute.
  */
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  arena= thd->is_stmt_prepare() ? thd->activate_stmt_arena_if_needed(&backup)
                                : NULL;
1504

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  for (i= 0, arg= args; i < nargs; i++, arg+= item_sep)
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  {
    Item* conv;
    uint32 dummy_offset;
    if (!String::needs_conversion(0, coll.collation,
                                  (*arg)->collation.collation,
                                  &dummy_offset))
      continue;

    if (!(conv= (*arg)->safe_charset_converter(coll.collation)))
    {
      if (nargs >=2 && nargs <= 3)
      {
        /* restore the original arguments for better error message */
        args[0]= safe_args[0];
1520
        args[item_sep]= safe_args[1];
1521
      }
1522
      my_coll_agg_error(args, nargs, fname, item_sep);
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      res= TRUE;
      break; // we cannot return here, we need to restore "arena".
    }
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    if ((*arg)->type() == Item::FIELD_ITEM)
      ((Item_field *)(*arg))->no_const_subst= 1;
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    /*
      If in statement prepare, then we create a converter for two
      constant items, do it once and then reuse it.
      If we're in execution of a prepared statement, arena is NULL,
      and the conv was created in runtime memory. This can be
      the case only if the argument is a parameter marker ('?'),
      because for all true constants the charset converter has already
      been created in prepare. In this case register the change for
      rollback.
    */
1538
    if (thd->is_stmt_prepare())
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      *arg= conv;
    else
      thd->change_item_tree(arg, conv);
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    /*
      We do not check conv->fixed, because Item_func_conv_charset which can
      be return by safe_charset_converter can't be fixed at creation
    */
    conv->fix_fields(thd, arg);
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  }
  if (arena)
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    thd->restore_active_arena(arena, &backup);
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  return res;
}


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void Item_ident_for_show::make_field(Send_field *tmp_field)
{
  tmp_field->table_name= tmp_field->org_table_name= table_name;
  tmp_field->db_name= db_name;
  tmp_field->col_name= tmp_field->org_col_name= field->field_name;
  tmp_field->charsetnr= field->charset()->number;
  tmp_field->length=field->field_length;
  tmp_field->type=field->type();
  tmp_field->flags= field->table->maybe_null ? 
    (field->flags & ~NOT_NULL_FLAG) : field->flags;
  tmp_field->decimals= 0;
}
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/**********************************************/

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Item_field::Item_field(Field *f)
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  :Item_ident(0, NullS, *f->table_name, f->field_name),
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   item_equal(0), no_const_subst(0),
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   have_privileges(0), any_privileges(0)
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{
  set_field(f);
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  /*
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    field_name and table_name should not point to garbage
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    if this item is to be reused
  */
  orig_table_name= orig_field_name= "";
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}

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Item_field::Item_field(THD *thd, Name_resolution_context *context_arg,
                       Field *f)
1585
  :Item_ident(context_arg, f->table->s->db.str, *f->table_name, f->field_name),
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   item_equal(0), no_const_subst(0),
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   have_privileges(0), any_privileges(0)
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{
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  /*
    We always need to provide Item_field with a fully qualified field
    name to avoid ambiguity when executing prepared statements like
    SELECT * from d1.t1, d2.t1; (assuming d1.t1 and d2.t1 have columns
    with same names).
    This is because prepared statements never deal with wildcards in
    select list ('*') and always fix fields using fully specified path
    (i.e. db.table.column).
    No check for OOM: if db_name is NULL, we'll just get
    "Field not found" error.
    We need to copy db_name, table_name and field_name because they must
    be allocated in the statement memory, not in table memory (the table
    structure can go away and pop up again between subsequent executions
    of a prepared statement).
  */
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  if (thd->stmt_arena->is_stmt_prepare_or_first_sp_execute())
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  {
    if (db_name)
      orig_db_name= thd->strdup(db_name);
    orig_table_name= thd->strdup(table_name);
    orig_field_name= thd->strdup(field_name);
    /*
      We don't restore 'name' in cleanup because it's not changed
      during execution. Still we need it to point to persistent
      memory if this item is to be reused.
    */
    name= (char*) orig_field_name;
  }
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  set_field(f);
}

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Item_field::Item_field(Name_resolution_context *context_arg,
                       const char *db_arg,const char *table_name_arg,
                       const char *field_name_arg)
  :Item_ident(context_arg, db_arg,table_name_arg,field_name_arg),
   field(0), result_field(0), item_equal(0), no_const_subst(0),
   have_privileges(0), any_privileges(0)
{
  collation.set(DERIVATION_IMPLICIT);
}

1631
// Constructor need to process subselect with temporary tables (see Item)
1632
Item_field::Item_field(THD *thd, Item_field *item)
1633
  :Item_ident(thd, item),
1634
   field(item->field),
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   result_field(item->result_field),
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   item_equal(item->item_equal),
   no_const_subst(item->no_const_subst),
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   have_privileges(item->have_privileges),
   any_privileges(item->any_privileges)
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{
  collation.set(DERIVATION_IMPLICIT);
}
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void Item_field::set_field(Field *field_par)
{
  field=result_field=field_par;			// for easy coding with fields
  maybe_null=field->maybe_null();
  decimals= field->decimals();
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  max_length= field_par->max_length();
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  table_name= *field_par->table_name;
  field_name= field_par->field_name;
1652
  db_name= field_par->table->s->db.str;
1653
  alias_name_used= field_par->table->alias_name_used;
1654
  unsigned_flag=test(field_par->flags & UNSIGNED_FLAG);
1655
  collation.set(field_par->charset(), DERIVATION_IMPLICIT);
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  fixed= 1;
}


/*
  Reset this item to point to a field from the new temporary table.
  This is used when we create a new temporary table for each execution
  of prepared statement.
*/

void Item_field::reset_field(Field *f)
{
  set_field(f);
  /* 'name' is pointing at field->field_name of old field */
  name= (char*) f->field_name;
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}

const char *Item_ident::full_name() const
{
  char *tmp;
1676
  if (!table_name || !field_name)
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    return field_name ? field_name : name ? name : "tmp_field";
1678
  if (db_name && db_name[0])
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  {
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    tmp=(char*) sql_alloc((uint) strlen(db_name)+(uint) strlen(table_name)+
			  (uint) strlen(field_name)+3);
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    strxmov(tmp,db_name,".",table_name,".",field_name,NullS);
  }
  else
  {
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    if (table_name[0])
    {
      tmp= (char*) sql_alloc((uint) strlen(table_name) +
			     (uint) strlen(field_name) + 2);
      strxmov(tmp, table_name, ".", field_name, NullS);
    }
    else
      tmp= (char*) field_name;
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  }
  return tmp;
}

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void Item_ident::print(String *str)
{
1700
  THD *thd= current_thd;
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  char d_name_buff[MAX_ALIAS_NAME], t_name_buff[MAX_ALIAS_NAME];
  const char *d_name= db_name, *t_name= table_name;
1703 1704
  if (lower_case_table_names== 1 ||
      (lower_case_table_names == 2 && !alias_name_used))
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  {
    if (table_name && table_name[0])
    {
      strmov(t_name_buff, table_name);
      my_casedn_str(files_charset_info, t_name_buff);
      t_name= t_name_buff;
    }
    if (db_name && db_name[0])
    {
      strmov(d_name_buff, db_name);
      my_casedn_str(files_charset_info, d_name_buff);
      d_name= d_name_buff;
    }
  }

1720 1721
  if (!table_name || !field_name)
  {
1722
    const char *nm= field_name ? field_name : name ? name : "tmp_field";
1723
    append_identifier(thd, str, nm, (uint) strlen(nm));
1724 1725
    return;
  }
1726
  if (db_name && db_name[0] && !alias_name_used)
1727
  {
1728 1729 1730
    if (!(cached_table && cached_table->belong_to_view &&
          cached_table->belong_to_view->compact_view_format))
    {
1731
      append_identifier(thd, str, d_name, (uint)strlen(d_name));
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      str->append('.');
    }
1734
    append_identifier(thd, str, t_name, (uint)strlen(t_name));
1735
    str->append('.');
1736
    append_identifier(thd, str, field_name, (uint)strlen(field_name));
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  }
  else
  {
    if (table_name[0])
    {
1742
      append_identifier(thd, str, t_name, (uint) strlen(t_name));
1743
      str->append('.');
1744
      append_identifier(thd, str, field_name, (uint) strlen(field_name));
1745 1746
    }
    else
1747
      append_identifier(thd, str, field_name, (uint) strlen(field_name));
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  }
}

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/* ARGSUSED */
String *Item_field::val_str(String *str)
{
1754
  DBUG_ASSERT(fixed == 1);
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  if ((null_value=field->is_null()))
    return 0;
1757
  str->set_charset(str_value.charset());
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  return field->val_str(str,&str_value);
}

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1762
double Item_field::val_real()
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{
1764
  DBUG_ASSERT(fixed == 1);
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  if ((null_value=field->is_null()))
    return 0.0;
  return field->val_real();
}

1770

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longlong Item_field::val_int()
{
1773
  DBUG_ASSERT(fixed == 1);
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  if ((null_value=field->is_null()))
    return 0;
  return field->val_int();
}


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my_decimal *Item_field::val_decimal(my_decimal *decimal_value)
{
  if ((null_value= field->is_null()))
    return 0;
  return field->val_decimal(decimal_value);
}


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String *Item_field::str_result(String *str)
{
  if ((null_value=result_field->is_null()))
    return 0;
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  str->set_charset(str_value.charset());
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  return result_field->val_str(str,&str_value);
}

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bool Item_field::get_date(TIME *ltime,uint fuzzydate)
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{
  if ((null_value=field->is_null()) || field->get_date(ltime,fuzzydate))
  {
    bzero((char*) ltime,sizeof(*ltime));
    return 1;
  }
  return 0;
}

1806
bool Item_field::get_date_result(TIME *ltime,uint fuzzydate)
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{
  if ((null_value=result_field->is_null()) ||
      result_field->get_date(ltime,fuzzydate))
  {
    bzero((char*) ltime,sizeof(*ltime));
    return 1;
  }
  return 0;
}

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bool Item_field::get_time(TIME *ltime)
{
  if ((null_value=field->is_null()) || field->get_time(ltime))
  {
    bzero((char*) ltime,sizeof(*ltime));
    return 1;
  }
  return 0;
}

double Item_field::val_result()
{
  if ((null_value=result_field->is_null()))
    return 0.0;
  return result_field->val_real();
}

longlong Item_field::val_int_result()
{
  if ((null_value=result_field->is_null()))
    return 0;
  return result_field->val_int();
}

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my_decimal *Item_field::val_decimal_result(my_decimal *decimal_value)
{
  if ((null_value= result_field->is_null()))
    return 0;
  return result_field->val_decimal(decimal_value);
}


bool Item_field::val_bool_result()
{
  if ((null_value= result_field->is_null()))
    return FALSE;
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  switch (result_field->result_type()) {
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  case INT_RESULT:
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    return result_field->val_int() != 0;
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  case DECIMAL_RESULT:
  {
    my_decimal decimal_value;
    my_decimal *val= result_field->val_decimal(&decimal_value);
    if (val)
      return !my_decimal_is_zero(val);
    return 0;
  }
  case REAL_RESULT:
  case STRING_RESULT:
    return result_field->val_real() != 0.0;
  case ROW_RESULT:
  default:
    DBUG_ASSERT(0);
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    return 0;                                   // Shut up compiler
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  }
}


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bool Item_field::eq(const Item *item, bool binary_cmp) const
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{
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  if (item->type() != FIELD_ITEM)
    return 0;
  
  Item_field *item_field= (Item_field*) item;
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  if (item_field->field && field)
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    return item_field->field == field;
  /*
    We may come here when we are trying to find a function in a GROUP BY
    clause from the select list.
    In this case the '100 % correct' way to do this would be to first
    run fix_fields() on the GROUP BY item and then retry this function, but
    I think it's better to relax the checking a bit as we will in
    most cases do the correct thing by just checking the field name.
    (In cases where we would choose wrong we would have to generate a
    ER_NON_UNIQ_ERROR).
  */
  return (!my_strcasecmp(system_charset_info, item_field->name,
			 field_name) &&
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	  (!item_field->table_name || !table_name ||
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	   (!my_strcasecmp(table_alias_charset, item_field->table_name,
			   table_name) &&
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	    (!item_field->db_name || !db_name ||
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	     (item_field->db_name && !strcmp(item_field->db_name,
					     db_name))))));
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}

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table_map Item_field::used_tables() const
{
  if (field->table->const_table)
    return 0;					// const item
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  return (depended_from ? OUTER_REF_TABLE_BIT : field->table->map);
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}

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Item *Item_field::get_tmp_table_item(THD *thd)
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{
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  Item_field *new_item= new Item_field(thd, this);
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  if (new_item)
    new_item->field= new_item->result_field;
  return new_item;
}
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/*
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  Create an item from a string we KNOW points to a valid longlong
  end \0 terminated number string.
  This is always 'signed'. Unsigned values are created with Item_uint()
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*/

Item_int::Item_int(const char *str_arg, uint length)
{
  char *end_ptr= (char*) str_arg + length;
  int error;
  value= my_strtoll10(str_arg, &end_ptr, &error);
  max_length= (uint) (end_ptr - str_arg);
  name= (char*) str_arg;
  fixed= 1;
}


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my_decimal *Item_int::val_decimal(my_decimal *decimal_value)
{
  int2my_decimal(E_DEC_FATAL_ERROR, value, unsigned_flag, decimal_value);
  return decimal_value;
}

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String *Item_int::val_str(String *str)
{
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  // following assert is redundant, because fixed=1 assigned in constructor
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  DBUG_ASSERT(fixed == 1);
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  str->set(value, &my_charset_bin);
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  return str;
}

void Item_int::print(String *str)
{
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  // my_charset_bin is good enough for numbers
  str_value.set(value, &my_charset_bin);
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  str->append(str_value);
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}

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Item_uint::Item_uint(const char *str_arg, uint length):
  Item_int(str_arg, length)
{
  unsigned_flag= 1;
}


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Item_uint::Item_uint(const char *str_arg, longlong i, uint length):
  Item_int(str_arg, i, length)
{
  unsigned_flag= 1;
}


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String *Item_uint::val_str(String *str)
{
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  // following assert is redundant, because fixed=1 assigned in constructor
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  DBUG_ASSERT(fixed == 1);
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  str->set((ulonglong) value, &my_charset_bin);
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  return str;
}

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void Item_uint::print(String *str)
{
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  // latin1 is good enough for numbers
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  str_value.set((ulonglong) value, default_charset());
  str->append(str_value);
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}

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Item_decimal::Item_decimal(const char *str_arg, uint length,
                           CHARSET_INFO *charset)
{
  str2my_decimal(E_DEC_FATAL_ERROR, str_arg, length, charset, &decimal_value);
  name= (char*) str_arg;
  decimals= (uint8) decimal_value.frac;
  fixed= 1;
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  max_length= my_decimal_precision_to_length(decimal_value.intg + decimals,
                                             decimals, unsigned_flag);
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}

Item_decimal::Item_decimal(longlong val, bool unsig)
{
  int2my_decimal(E_DEC_FATAL_ERROR, val, unsig, &decimal_value);
  decimals= (uint8) decimal_value.frac;
  fixed= 1;
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  max_length= my_decimal_precision_to_length(decimal_value.intg + decimals,
                                             decimals, unsigned_flag);
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}


Item_decimal::Item_decimal(double val, int precision, int scale)
{
  double2my_decimal(E_DEC_FATAL_ERROR, val, &decimal_value);
  decimals= (uint8) decimal_value.frac;
  fixed= 1;
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  max_length= my_decimal_precision_to_length(decimal_value.intg + decimals,
                                             decimals, unsigned_flag);
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}


Item_decimal::Item_decimal(const char *str, const my_decimal *val_arg,
                           uint decimal_par, uint length)
{
  my_decimal2decimal(val_arg, &decimal_value);
  name= (char*) str;
  decimals= (uint8) decimal_par;
  max_length= length;
  fixed= 1;
}


Item_decimal::Item_decimal(my_decimal *value_par)
{
  my_decimal2decimal(value_par, &decimal_value);
  decimals= (uint8) decimal_value.frac;
  fixed= 1;
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  max_length= my_decimal_precision_to_length(decimal_value.intg + decimals,
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                                             decimals, unsigned_flag);
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}


Item_decimal::Item_decimal(const char *bin, int precision, int scale)
{
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  binary2my_decimal(E_DEC_FATAL_ERROR, bin,
                    &decimal_value, precision, scale);
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  decimals= (uint8) decimal_value.frac;
  fixed= 1;
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  max_length= my_decimal_precision_to_length(precision, decimals,
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                                             unsigned_flag);
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}


longlong Item_decimal::val_int()
{
  longlong result;
  my_decimal2int(E_DEC_FATAL_ERROR, &decimal_value, unsigned_flag, &result);
  return result;
}

double Item_decimal::val_real()
{
  double result;
  my_decimal2double(E_DEC_FATAL_ERROR, &decimal_value, &result);
  return result;
}

String *Item_decimal::val_str(String *result)
{
  result->set_charset(&my_charset_bin);
  my_decimal2string(E_DEC_FATAL_ERROR, &decimal_value, 0, 0, 0, result);
  return result;
}

void Item_decimal::print(String *str)
{
  my_decimal2string(E_DEC_FATAL_ERROR, &decimal_value, 0, 0, 0, &str_value);
  str->append(str_value);
}


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bool Item_decimal::eq(const Item *item, bool binary_cmp) const
{
  if (type() == item->type() && item->basic_const_item())
  {
    /*
      We need to cast off const to call val_decimal(). This should
      be OK for a basic constant. Additionally, we can pass 0 as
      a true decimal constant will return its internal decimal
      storage and ignore the argument.
    */
    Item *arg= (Item*) item;
    my_decimal *value= arg->val_decimal(0);
    return !my_decimal_cmp(&decimal_value, value);
  }
  return 0;
}


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void Item_decimal::set_decimal_value(my_decimal *value_par)
{
  my_decimal2decimal(value_par, &decimal_value);
  decimals= (uint8) decimal_value.frac;
  unsigned_flag= !decimal_value.sign();
  max_length= my_decimal_precision_to_length(decimal_value.intg + decimals,
                                             decimals, unsigned_flag);
}


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String *Item_float::val_str(String *str)
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{
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  // following assert is redundant, because fixed=1 assigned in constructor
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  DBUG_ASSERT(fixed == 1);
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  str->set_real(value,decimals,&my_charset_bin);
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  return str;
}

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my_decimal *Item_float::val_decimal(my_decimal *decimal_value)
{
  // following assert is redundant, because fixed=1 assigned in constructor
  DBUG_ASSERT(fixed == 1);
  double2my_decimal(E_DEC_FATAL_ERROR, value, decimal_value);
  return (decimal_value);
}


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void Item_string::print(String *str)
{
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  str->append('_');
  str->append(collation.collation->csname);
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  str->append('\'');
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  str_value.print(str);
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  str->append('\'');
}

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inline bool check_if_only_end_space(CHARSET_INFO *cs, char *str, char *end)
{
  return str+ cs->cset->scan(cs, str, end, MY_SEQ_SPACES) == end;
}


double Item_string::val_real()
{
  DBUG_ASSERT(fixed == 1);
  int error;
  char *end, *org_end;
  double tmp;
  CHARSET_INFO *cs= str_value.charset();

  org_end= (char*) str_value.ptr() + str_value.length();
  tmp= my_strntod(cs, (char*) str_value.ptr(), str_value.length(), &end,
                  &error);
  if (error || (end != org_end && !check_if_only_end_space(cs, end, org_end)))
  {
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    /*
      We can use str_value.ptr() here as Item_string is gurantee to put an
      end \0 here.
    */
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    push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                        ER_TRUNCATED_WRONG_VALUE,
                        ER(ER_TRUNCATED_WRONG_VALUE), "DOUBLE",
                        str_value.ptr());
  }
  return tmp;
}


longlong Item_string::val_int()
{
  DBUG_ASSERT(fixed == 1);
  int err;
  longlong tmp;
  char *end= (char*) str_value.ptr()+ str_value.length();
  char *org_end= end;
  CHARSET_INFO *cs= str_value.charset();

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  tmp= (*(cs->cset->strtoll10))(cs, str_value.ptr(), &end, &err);
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  /*
    TODO: Give error if we wanted a signed integer and we got an unsigned
    one
  */
  if (err > 0 ||
      (end != org_end && !check_if_only_end_space(cs, end, org_end)))
  {
    push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                        ER_TRUNCATED_WRONG_VALUE,
                        ER(ER_TRUNCATED_WRONG_VALUE), "INTEGER",
                        str_value.ptr());
  }
  return tmp;
}


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my_decimal *Item_string::val_decimal(my_decimal *decimal_value)
{
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  return val_decimal_from_string(decimal_value);
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}


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bool Item_null::eq(const Item *item, bool binary_cmp) const
{ return item->type() == type(); }
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double Item_null::val_real()
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{
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  // following assert is redundant, because fixed=1 assigned in constructor
  DBUG_ASSERT(fixed == 1);
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  null_value=1;
  return 0.0;
}
longlong Item_null::val_int()
{
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  // following assert is redundant, because fixed=1 assigned in constructor
  DBUG_ASSERT(fixed == 1);
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  null_value=1;
  return 0;
}
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/* ARGSUSED */
String *Item_null::val_str(String *str)
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{
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  // following assert is redundant, because fixed=1 assigned in constructor
  DBUG_ASSERT(fixed == 1);
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  null_value=1;
  return 0;
}
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my_decimal *Item_null::val_decimal(my_decimal *decimal_value)
{
  return 0;
}

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Item *Item_null::safe_charset_converter(CHARSET_INFO *tocs)
{
  collation.set(tocs);
  return this;
}

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/*********************** Item_param related ******************************/

/* 
  Default function of Item_param::set_param_func, so in case
  of malformed packet the server won't SIGSEGV
*/

static void
default_set_param_func(Item_param *param,
                       uchar **pos __attribute__((unused)),
                       ulong len __attribute__((unused)))
{
  param->set_null();
}

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Item_param::Item_param(unsigned pos_in_query_arg) :
  state(NO_VALUE),
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  item_result_type(STRING_RESULT),
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  /* Don't pretend to be a literal unless value for this item is set. */
  item_type(PARAM_ITEM),
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  param_type(MYSQL_TYPE_VARCHAR),
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  pos_in_query(pos_in_query_arg),
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  set_param_func(default_set_param_func)
{
  name= (char*) "?";
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  /* 
    Since we can't say whenever this item can be NULL or cannot be NULL
    before mysql_stmt_execute(), so we assuming that it can be NULL until
    value is set.
  */
  maybe_null= 1;
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  cnvitem= new Item_string("", 0, &my_charset_bin, DERIVATION_COERCIBLE);
  cnvstr.set(cnvbuf, sizeof(cnvbuf), &my_charset_bin);
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}
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void Item_param::set_null()
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{
  DBUG_ENTER("Item_param::set_null");
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  /* These are cleared after each execution by reset() method */
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  null_value= 1;
  /* 
    Because of NULL and string values we need to set max_length for each new
    placeholder value: user can submit NULL for any placeholder type, and 
    string length can be different in each execution.
  */
  max_length= 0;
  decimals= 0;
  state= NULL_VALUE;
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  item_type= Item::NULL_ITEM;
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  DBUG_VOID_RETURN;
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}

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void Item_param::set_int(longlong i, uint32 max_length_arg)
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{
  DBUG_ENTER("Item_param::set_int");
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  value.integer= (longlong) i;
  state= INT_VALUE;
  max_length= max_length_arg;
  decimals= 0;
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  maybe_null= 0;
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  DBUG_VOID_RETURN;
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}

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void Item_param::set_double(double d)
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{
  DBUG_ENTER("Item_param::set_double");
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  value.real= d;
  state= REAL_VALUE;
  max_length= DBL_DIG + 8;
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  decimals= NOT_FIXED_DEC;
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  maybe_null= 0;
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  DBUG_VOID_RETURN;
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}


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/*
  Set decimal parameter value from string.

  SYNOPSIS
    set_decimal()
      str    - character string
      length - string length

  NOTE
    as we use character strings to send decimal values in
    binary protocol, we use str2my_decimal to convert it to
    internal decimal value.
*/
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void Item_param::set_decimal(const char *str, ulong length)
{
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  char *end;
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  DBUG_ENTER("Item_param::set_decimal");

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  end= (char*) str+length;
  str2my_decimal(E_DEC_FATAL_ERROR, str, &decimal_value, &end);
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  state= DECIMAL_VALUE;
  decimals= decimal_value.frac;
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  max_length= my_decimal_precision_to_length(decimal_value.precision(),
                                             decimals, unsigned_flag);
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  maybe_null= 0;
  DBUG_VOID_RETURN;
}


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/*
  Set parameter value from TIME value.

  SYNOPSIS
    set_time()
      tm             - datetime value to set (time_type is ignored)
      type           - type of datetime value
      max_length_arg - max length of datetime value as string

  NOTE
    If we value to be stored is not normalized, zero value will be stored
    instead and proper warning will be produced. This function relies on
    the fact that even wrong value sent over binary protocol fits into
    MAX_DATE_STRING_REP_LENGTH buffer.
*/
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void Item_param::set_time(TIME *tm, timestamp_type type, uint32 max_length_arg)
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{ 
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  DBUG_ENTER("Item_param::set_time");
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  value.time= *tm;
  value.time.time_type= type;
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  if (value.time.year > 9999 || value.time.month > 12 ||
      value.time.day > 31 ||
      type != MYSQL_TIMESTAMP_TIME && value.time.hour > 23 ||
      value.time.minute > 59 || value.time.second > 59)
  {
    char buff[MAX_DATE_STRING_REP_LENGTH];
    uint length= my_TIME_to_str(&value.time, buff);
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    make_truncated_value_warning(current_thd, buff, length, type, 0);
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    set_zero_time(&value.time, MYSQL_TIMESTAMP_ERROR);
  }

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  state= TIME_VALUE;
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  maybe_null= 0;
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  max_length= max_length_arg;
  decimals= 0;
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  DBUG_VOID_RETURN;
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}

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bool Item_param::set_str(const char *str, ulong length)
{
  DBUG_ENTER("Item_param::set_str");
  /*
    Assign string with no conversion: data is converted only after it's
    been written to the binary log.
  */
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  uint dummy_errors;
  if (str_value.copy(str, length, &my_charset_bin, &my_charset_bin,
                     &dummy_errors))
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    DBUG_RETURN(TRUE);
  state= STRING_VALUE;
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  max_length= length;
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  maybe_null= 0;
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  /* max_length and decimals are set after charset conversion */
  /* sic: str may be not null-terminated, don't add DBUG_PRINT here */
  DBUG_RETURN(FALSE);
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}


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bool Item_param::set_longdata(const char *str, ulong length)
{
  DBUG_ENTER("Item_param::set_longdata");

  /*
    If client character set is multibyte, end of long data packet
    may hit at the middle of a multibyte character.  Additionally,
    if binary log is open we must write long data value to the
    binary log in character set of client. This is why we can't
    convert long data to connection character set as it comes
    (here), and first have to concatenate all pieces together,
    write query to the binary log and only then perform conversion.
  */
  if (str_value.append(str, length, &my_charset_bin))
    DBUG_RETURN(TRUE);
  state= LONG_DATA_VALUE;
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  maybe_null= 0;
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  DBUG_RETURN(FALSE);
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}


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/*
  Set parameter value from user variable value.

  SYNOPSIS
   set_from_user_var
     thd   Current thread
     entry User variable structure (NULL means use NULL value)

  RETURN
    0 OK
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    1 Out of memory
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*/

bool Item_param::set_from_user_var(THD *thd, const user_var_entry *entry)
{
  DBUG_ENTER("Item_param::set_from_user_var");
  if (entry && entry->value)
  {
    item_result_type= entry->type;
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    switch (entry->type) {
    case REAL_RESULT:
      set_double(*(double*)entry->value);
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      item_type= Item::REAL_ITEM;
      item_result_type= REAL_RESULT;
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      break;
    case INT_RESULT:
      set_int(*(longlong*)entry->value, 21);
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      item_type= Item::INT_ITEM;
      item_result_type= INT_RESULT;
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      break;
    case STRING_RESULT:
2463
    {
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      CHARSET_INFO *fromcs= entry->collation.collation;
      CHARSET_INFO *tocs= thd->variables.collation_connection;
      uint32 dummy_offset;

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      value.cs_info.character_set_of_placeholder= 
        value.cs_info.character_set_client= fromcs;
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      /*
        Setup source and destination character sets so that they
        are different only if conversion is necessary: this will
        make later checks easier.
      */
      value.cs_info.final_character_set_of_str_value=
        String::needs_conversion(0, fromcs, tocs, &dummy_offset) ?
        tocs : fromcs;
      /*
        Exact value of max_length is not known unless data is converted to
        charset of connection, so we have to set it later.
      */
      item_type= Item::STRING_ITEM;
      item_result_type= STRING_RESULT;

      if (set_str((const char *)entry->value, entry->length))
        DBUG_RETURN(1);
      break;
    }
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    case DECIMAL_RESULT:
    {
      const my_decimal *ent_value= (const my_decimal *)entry->value;
      my_decimal2decimal(ent_value, &decimal_value);
      state= DECIMAL_VALUE;
      decimals= ent_value->frac;
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      max_length= my_decimal_precision_to_length(ent_value->precision(),
                                                 decimals, unsigned_flag);
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      break;
    }
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    default:
      DBUG_ASSERT(0);
      set_null();
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    }
  }
  else
    set_null();

  DBUG_RETURN(0);
}

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/*
    Resets parameter after execution.
  
  SYNOPSIS
     Item_param::reset()
 
  NOTES
    We clear null_value here instead of setting it in set_* methods, 
    because we want more easily handle case for long data.
*/

void Item_param::reset()
2522
{
2523
  DBUG_ENTER("Item_param::reset");
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  /* Shrink string buffer if it's bigger than max possible CHAR column */
  if (str_value.alloced_length() > MAX_CHAR_WIDTH)
    str_value.free();
  else
    str_value.length(0);
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  str_value_ptr.length(0);
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  /*
2531
    We must prevent all charset conversions until data has been written
2532
    to the binary log.
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  */
  str_value.set_charset(&my_charset_bin);
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  collation.set(&my_charset_bin, DERIVATION_COERCIBLE);
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  state= NO_VALUE;
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  maybe_null= 1;
  null_value= 0;
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  /*
    Don't reset item_type to PARAM_ITEM: it's only needed to guard
    us from item optimizations at prepare stage, when item doesn't yet
    contain a literal of some kind.
    In all other cases when this object is accessed its value is
    set (this assumption is guarded by 'state' and
    DBUG_ASSERTS(state != NO_VALUE) in all Item_param::get_*
    methods).
  */
2548
  DBUG_VOID_RETURN;
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}


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int Item_param::save_in_field(Field *field, bool no_conversions)
2553 2554
{
  field->set_notnull();
2555 2556 2557

  switch (state) {
  case INT_VALUE:
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    return field->store(value.integer, unsigned_flag);
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  case REAL_VALUE:
    return field->store(value.real);
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  case DECIMAL_VALUE:
    return field->store_decimal(&decimal_value);
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  case TIME_VALUE:
    field->store_time(&value.time, value.time.time_type);
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    return 0;
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  case STRING_VALUE:
  case LONG_DATA_VALUE:
    return field->store(str_value.ptr(), str_value.length(),
                        str_value.charset());
  case NULL_VALUE:
2571
    return set_field_to_null_with_conversions(field, no_conversions);
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  case NO_VALUE:
  default:
    DBUG_ASSERT(0);
2575
  }
2576
  return 1;
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}

2579

2580 2581
bool Item_param::get_time(TIME *res)
{
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  if (state == TIME_VALUE)
  {
    *res= value.time;
    return 0;
  }
  /*
    If parameter value isn't supplied assertion will fire in val_str()
    which is called from Item::get_time().
  */
  return Item::get_time(res);
2592
}
2593

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bool Item_param::get_date(TIME *res, uint fuzzydate)
{
  if (state == TIME_VALUE)
  {
    *res= value.time;
    return 0;
  }
  return Item::get_date(res, fuzzydate);
}


2606
double Item_param::val_real()
2607
{
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  switch (state) {
  case REAL_VALUE:
    return value.real;
  case INT_VALUE:
    return (double) value.integer;
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  case DECIMAL_VALUE:
  {
    double result;
    my_decimal2double(E_DEC_FATAL_ERROR, &decimal_value, &result);
    return result;
  }
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  case STRING_VALUE:
  case LONG_DATA_VALUE:
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  {
    int dummy_err;
    char *end_not_used;
    return my_strntod(str_value.charset(), (char*) str_value.ptr(),
                      str_value.length(), &end_not_used, &dummy_err);
  }
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  case TIME_VALUE:
    /*
      This works for example when user says SELECT ?+0.0 and supplies
      time value for the placeholder.
    */
2632
    return ulonglong2double(TIME_to_ulonglong(&value.time));
2633
  case NULL_VALUE:
2634
    return 0.0;
2635
  default:
2636
    DBUG_ASSERT(0);
2637
  }
2638
  return 0.0;
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} 

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2642 2643
longlong Item_param::val_int() 
{ 
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  switch (state) {
  case REAL_VALUE:
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    return (longlong) rint(value.real);
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  case INT_VALUE:
    return value.integer;
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  case DECIMAL_VALUE:
  {
    longlong i;
    my_decimal2int(E_DEC_FATAL_ERROR, &decimal_value, unsigned_flag, &i);
    return i;
  }
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  case STRING_VALUE:
  case LONG_DATA_VALUE:
    {
      int dummy_err;
      return my_strntoll(str_value.charset(), str_value.ptr(),
                         str_value.length(), 10, (char**) 0, &dummy_err);
    }
  case TIME_VALUE:
    return (longlong) TIME_to_ulonglong(&value.time);
  case NULL_VALUE:
    return 0; 
2666
  default:
2667
    DBUG_ASSERT(0);
2668
  }
2669
  return 0;
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}

2672

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my_decimal *Item_param::val_decimal(my_decimal *dec)
{
  switch (state) {
  case DECIMAL_VALUE:
    return &decimal_value;
  case REAL_VALUE:
    double2my_decimal(E_DEC_FATAL_ERROR, value.real, dec);
    return dec;
  case INT_VALUE:
    int2my_decimal(E_DEC_FATAL_ERROR, value.integer, unsigned_flag, dec);
    return dec;
  case STRING_VALUE:
  case LONG_DATA_VALUE:
    string2my_decimal(E_DEC_FATAL_ERROR, &str_value, dec);
    return dec;
  case TIME_VALUE:
  {
    longlong i= (longlong) TIME_to_ulonglong(&value.time);
    int2my_decimal(E_DEC_FATAL_ERROR, i, 0, dec);
    return dec;
  }
  case NULL_VALUE:
    return 0; 
  default:
    DBUG_ASSERT(0);
  }
  return 0;
}


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String *Item_param::val_str(String* str) 
{ 
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  switch (state) {
  case STRING_VALUE:
  case LONG_DATA_VALUE:
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    return &str_value_ptr;
2709
  case REAL_VALUE:
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    str->set_real(value.real, NOT_FIXED_DEC, &my_charset_bin);
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    return str;
  case INT_VALUE:
    str->set(value.integer, &my_charset_bin);
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    return str;
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  case DECIMAL_VALUE:
    if (my_decimal2string(E_DEC_FATAL_ERROR, &decimal_value,
                          0, 0, 0, str) <= 1)
      return str;
    return NULL;
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  case TIME_VALUE:
  {
2722
    if (str->reserve(MAX_DATE_STRING_REP_LENGTH))
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      break;
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    str->length((uint) my_TIME_to_str(&value.time, (char*) str->ptr()));
    str->set_charset(&my_charset_bin);
2726
    return str;
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  }
  case NULL_VALUE:
    return NULL; 
2730
  default:
2731
    DBUG_ASSERT(0);
2732
  }
2733
  return str;
2734
}
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/*
  Return Param item values in string format, for generating the dynamic 
  query used in update/binary logs
2739 2740
  TODO: change interface and implementation to fill log data in place
  and avoid one more memcpy/alloc between str and log string.
2741 2742
*/

2743
const String *Item_param::query_val_str(String* str) const
2744
{
2745 2746 2747 2748 2749
  switch (state) {
  case INT_VALUE:
    str->set(value.integer, &my_charset_bin);
    break;
  case REAL_VALUE:
2750
    str->set_real(value.real, NOT_FIXED_DEC, &my_charset_bin);
2751
    break;
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  case DECIMAL_VALUE:
    if (my_decimal2string(E_DEC_FATAL_ERROR, &decimal_value,
                          0, 0, 0, str) > 1)
      return &my_null_string;
    break;
2757
  case TIME_VALUE:
2758
    {
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      char *buf, *ptr;
      str->length(0);
      /*
        TODO: in case of error we need to notify replication
        that binary log contains wrong statement 
      */
2765
      if (str->reserve(MAX_DATE_STRING_REP_LENGTH+3))
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        break; 

      /* Create date string inplace */
      buf= str->c_ptr_quick();
      ptr= buf;
      *ptr++= '\'';
2772
      ptr+= (uint) my_TIME_to_str(&value.time, ptr);
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      *ptr++= '\'';
      str->length((uint32) (ptr - buf));
      break;
2776
    }
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  case STRING_VALUE:
  case LONG_DATA_VALUE:
2779
    {
2780
      str->length(0);
2781
      append_query_string(value.cs_info.character_set_client, &str_value, str);
2782
      break;
2783
    }
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  case NULL_VALUE:
    return &my_null_string;
  default:
    DBUG_ASSERT(0);
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  }
  return str;
}
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/*
  Convert string from client character set to the character set of
  connection.
*/

bool Item_param::convert_str_value(THD *thd)
{
  bool rc= FALSE;
  if (state == STRING_VALUE || state == LONG_DATA_VALUE)
  {
    /*
      Check is so simple because all charsets were set up properly
      in setup_one_conversion_function, where typecode of
      placeholder was also taken into account: the variables are different
      here only if conversion is really necessary.
    */
    if (value.cs_info.final_character_set_of_str_value !=
2810
        value.cs_info.character_set_of_placeholder)
2811 2812
    {
      rc= thd->convert_string(&str_value,
2813
                              value.cs_info.character_set_of_placeholder,
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                              value.cs_info.final_character_set_of_str_value);
    }
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    else
      str_value.set_charset(value.cs_info.final_character_set_of_str_value);
    /* Here str_value is guaranteed to be in final_character_set_of_str_value */

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    max_length= str_value.length();
    decimals= 0;
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    /*
      str_value_ptr is returned from val_str(). It must be not alloced
      to prevent it's modification by val_str() invoker.
    */
    str_value_ptr.set(str_value.ptr(), str_value.length(),
                      str_value.charset());
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    /* Synchronize item charset with value charset */
    collation.set(str_value.charset(), DERIVATION_COERCIBLE);
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  }
  return rc;
}

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bool Item_param::basic_const_item() const
{
  if (state == NO_VALUE || state == TIME_VALUE)
    return FALSE;
  return TRUE;
}

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Item *
Item_param::new_item()
{
  /* see comments in the header file */
  switch (state) {
  case NULL_VALUE:
    return new Item_null(name);
  case INT_VALUE:
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    return (unsigned_flag ?
            new Item_uint(name, value.integer, max_length) :
            new Item_int(name, value.integer, max_length));
2854
  case REAL_VALUE:
2855
    return new Item_float(name, value.real, decimals, max_length);
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  case STRING_VALUE:
  case LONG_DATA_VALUE:
    return new Item_string(name, str_value.c_ptr_quick(), str_value.length(),
                           str_value.charset());
  case TIME_VALUE:
    break;
  case NO_VALUE:
  default:
    DBUG_ASSERT(0);
  };
  return 0;
}


bool
Item_param::eq(const Item *arg, bool binary_cmp) const
{
  Item *item;
  if (!basic_const_item() || !arg->basic_const_item() || arg->type() != type())
    return FALSE;
  /*
    We need to cast off const to call val_int(). This should be OK for
    a basic constant.
  */
  item= (Item*) arg;

  switch (state) {
  case NULL_VALUE:
    return TRUE;
  case INT_VALUE:
    return value.integer == item->val_int() &&
           unsigned_flag == item->unsigned_flag;
  case REAL_VALUE:
2889
    return value.real == item->val_real();
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  case STRING_VALUE:
  case LONG_DATA_VALUE:
    if (binary_cmp)
      return !stringcmp(&str_value, &item->str_value);
    return !sortcmp(&str_value, &item->str_value, collation.collation);
  default:
    break;
  }
  return FALSE;
}

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/* End of Item_param related */

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void Item_param::print(String *str)
{
  if (state == NO_VALUE)
  {
    str->append('?');
  }
  else
  {
2911
    char buffer[STRING_BUFFER_USUAL_SIZE];
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    String tmp(buffer, sizeof(buffer), &my_charset_bin);
    const String *res;
    res= query_val_str(&tmp);
    str->append(*res);
  }
}


/****************************************************************************
  Item_copy_string
****************************************************************************/
2923

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void Item_copy_string::copy()
{
  String *res=item->val_str(&str_value);
  if (res && res != &str_value)
    str_value.copy(*res);
  null_value=item->null_value;
}

/* ARGSUSED */
String *Item_copy_string::val_str(String *str)
{
2935
  // Item_copy_string is used without fix_fields call
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  if (null_value)
    return (String*) 0;
  return &str_value;
}

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my_decimal *Item_copy_string::val_decimal(my_decimal *decimal_value)
{
  // Item_copy_string is used without fix_fields call
  if (null_value)
    return 0;
  string2my_decimal(E_DEC_FATAL_ERROR, &str_value, decimal_value);
  return (decimal_value);
}



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int Item_copy_string::save_in_field(Field *field, bool no_conversions)
{
  if (null_value)
    return set_field_to_null(field);
  field->set_notnull();
  return field->store(str_value.ptr(),str_value.length(),
		      collation.collation);
}

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/*
2963
  Functions to convert item to field (for send_fields)
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*/

/* ARGSUSED */
2967
bool Item::fix_fields(THD *thd, Item **ref)
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{
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  // We do not check fields which are fixed during construction
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  DBUG_ASSERT(fixed == 0 || basic_const_item());
2972
  fixed= 1;
2973
  return FALSE;
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}

2976
double Item_ref_null_helper::val_real()
2977
{
2978
  DBUG_ASSERT(fixed == 1);
2979
  double tmp= (*ref)->val_result();
2980
  owner->was_null|= null_value= (*ref)->null_value;
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  return tmp;
}
2983 2984


2985 2986
longlong Item_ref_null_helper::val_int()
{
2987
  DBUG_ASSERT(fixed == 1);
2988
  longlong tmp= (*ref)->val_int_result();
2989
  owner->was_null|= null_value= (*ref)->null_value;
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  return tmp;
}
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my_decimal *Item_ref_null_helper::val_decimal(my_decimal *decimal_value)
{
  DBUG_ASSERT(fixed == 1);
  my_decimal *val= (*ref)->val_decimal_result(decimal_value);
  owner->was_null|= null_value= (*ref)->null_value;
  return val;
}


bool Item_ref_null_helper::val_bool()
{
  DBUG_ASSERT(fixed == 1);
  bool val= (*ref)->val_bool_result();
  owner->was_null|= null_value= (*ref)->null_value;
  return val;
}


3012 3013
String* Item_ref_null_helper::val_str(String* s)
{
3014
  DBUG_ASSERT(fixed == 1);
3015
  String* tmp= (*ref)->str_result(s);
3016
  owner->was_null|= null_value= (*ref)->null_value;
3017 3018
  return tmp;
}
3019 3020


3021
bool Item_ref_null_helper::get_date(TIME *ltime, uint fuzzydate)
3022 3023 3024
{  
  return (owner->was_null|= null_value= (*ref)->get_date(ltime, fuzzydate));
}
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/*
3028
  Mark item and SELECT_LEXs as dependent if item was resolved in outer SELECT
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  SYNOPSIS
    mark_as_dependent()
3032
    thd - thread handler
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    last - select from which current item depend
    current  - current select
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    resolved_item - item which was resolved in outer SELECT(for warning)
    mark_item - item which should be marked (can be differ in case of
                substitution)
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*/

3040
static void mark_as_dependent(THD *thd, SELECT_LEX *last, SELECT_LEX *current,
3041
                              Item_ident *resolved_item,
3042
                              Item_ident *mark_item)
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{
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  const char *db_name= (resolved_item->db_name ?
                        resolved_item->db_name : "");
  const char *table_name= (resolved_item->table_name ?
                           resolved_item->table_name : "");
3048
  /* store pointer on SELECT_LEX from which item is dependent */
3049 3050
  if (mark_item)
    mark_item->depended_from= last;
3051
  current->mark_as_dependent(last);
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  if (thd->lex->describe & DESCRIBE_EXTENDED)
3053 3054 3055
  {
    char warn_buff[MYSQL_ERRMSG_SIZE];
    sprintf(warn_buff, ER(ER_WARN_FIELD_RESOLVED),
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            db_name, (db_name[0] ? "." : ""),
            table_name, (table_name [0] ? "." : ""),
3058
            resolved_item->field_name,
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	    current->select_number, last->select_number);
    push_warning(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
		 ER_WARN_FIELD_RESOLVED, warn_buff);
  }
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}


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/*
  Mark range of selects and resolved identifier (field/reference) item as
  dependent

  SYNOPSIS
    mark_select_range_as_dependent()
    thd           - thread handler
    last_select   - select where resolved_item was resolved
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    current_sel   - current select (select where resolved_item was placed)
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    found_field   - field which was found during resolving
    found_item    - Item which was found during resolving (if resolved
                    identifier belongs to VIEW)
    resolved_item - Identifier which was resolved

  NOTE:
    We have to mark all items between current_sel (including) and
    last_select (excluding) as dependend (select before last_select should
    be marked with actual table mask used by resolved item, all other with
    OUTER_REF_TABLE_BIT) and also write dependence information to Item of
    resolved identifier.
*/

void mark_select_range_as_dependent(THD *thd,
                                    SELECT_LEX *last_select,
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                                    SELECT_LEX *current_sel,
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                                    Field *found_field, Item *found_item,
                                    Item_ident *resolved_item)
{
  /*
    Go from current SELECT to SELECT where field was resolved (it
    have to be reachable from current SELECT, because it was already
    done once when we resolved this field and cached result of
    resolving)
  */
  SELECT_LEX *previous_select= current_sel;
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  for (; previous_select->outer_select() != last_select;
       previous_select= previous_select->outer_select())
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  {
    Item_subselect *prev_subselect_item=
      previous_select->master_unit()->item;
    prev_subselect_item->used_tables_cache|= OUTER_REF_TABLE_BIT;
    prev_subselect_item->const_item_cache= 0;
  }
  {
    Item_subselect *prev_subselect_item=
      previous_select->master_unit()->item;
    Item_ident *dependent= resolved_item;
    if (found_field == view_ref_found)
    {
      Item::Type type= found_item->type();
      prev_subselect_item->used_tables_cache|=
        found_item->used_tables();
      dependent= ((type == Item::REF_ITEM || type == Item::FIELD_ITEM) ?
                  (Item_ident*) found_item :
                  0);
    }
    else
      prev_subselect_item->used_tables_cache|=
        found_field->table->map;
    prev_subselect_item->const_item_cache= 0;
    mark_as_dependent(thd, last_select, current_sel, resolved_item,
                      dependent);
  }
}
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/*
  Search a GROUP BY clause for a field with a certain name.

  SYNOPSIS
    find_field_in_group_list()
    find_item  the item being searched for
    group_list GROUP BY clause

  DESCRIPTION
    Search the GROUP BY list for a column named as find_item. When searching
    preference is given to columns that are qualified with the same table (and
    database) name as the one being searched for.

  RETURN
    - the found item on success
    - NULL if find_item is not in group_list
*/

static Item** find_field_in_group_list(Item *find_item, ORDER *group_list)
{
  const char *db_name;
  const char *table_name;
  const char *field_name;
  ORDER      *found_group= NULL;
  int         found_match_degree= 0;
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  Item_ident *cur_field;
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  int         cur_match_degree= 0;
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  char        name_buff[NAME_LEN+1];
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  if (find_item->type() == Item::FIELD_ITEM ||
      find_item->type() == Item::REF_ITEM)
  {
    db_name=    ((Item_ident*) find_item)->db_name;
    table_name= ((Item_ident*) find_item)->table_name;
    field_name= ((Item_ident*) find_item)->field_name;
  }
  else
    return NULL;

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  if (db_name && lower_case_table_names)
  {
    /* Convert database to lower case for comparison */
    strmake(name_buff, db_name, sizeof(name_buff)-1);
    my_casedn_str(files_charset_info, name_buff);
    db_name= name_buff;
  }

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  DBUG_ASSERT(field_name != 0);
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  for (ORDER *cur_group= group_list ; cur_group ; cur_group= cur_group->next)
  {
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    if ((*(cur_group->item))->real_item()->type() == Item::FIELD_ITEM)
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    {
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      cur_field= (Item_ident*) *cur_group->item;
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      cur_match_degree= 0;
      
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      DBUG_ASSERT(cur_field->field_name != 0);
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      if (!my_strcasecmp(system_charset_info,
                         cur_field->field_name, field_name))
        ++cur_match_degree;
      else
        continue;

      if (cur_field->table_name && table_name)
      {
        /* If field_name is qualified by a table name. */
        if (strcmp(cur_field->table_name, table_name))
          /* Same field names, different tables. */
          return NULL;

        ++cur_match_degree;
        if (cur_field->db_name && db_name)
        {
          /* If field_name is also qualified by a database name. */
          if (strcmp(cur_field->db_name, db_name))
            /* Same field names, different databases. */
            return NULL;
          ++cur_match_degree;
        }
      }

      if (cur_match_degree > found_match_degree)
      {
        found_match_degree= cur_match_degree;
        found_group= cur_group;
      }
      else if (found_group && (cur_match_degree == found_match_degree) &&
               ! (*(found_group->item))->eq(cur_field, 0))
      {
        /*
          If the current resolve candidate matches equally well as the current
          best match, they must reference the same column, otherwise the field
          is ambiguous.
        */
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        my_error(ER_NON_UNIQ_ERROR, MYF(0),
                 find_item->full_name(), current_thd->where);
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        return NULL;
      }
    }
  }

  if (found_group)
    return found_group->item;
  else
    return NULL;
}


/*
  Resolve a column reference in a sub-select.

  SYNOPSIS
    resolve_ref_in_select_and_group()
    thd     current thread
    ref     column reference being resolved
    select  the sub-select that ref is resolved against

  DESCRIPTION
    Resolve a column reference (usually inside a HAVING clause) against the
    SELECT and GROUP BY clauses of the query described by 'select'. The name
    resolution algorithm searches both the SELECT and GROUP BY clauses, and in
    case of a name conflict prefers GROUP BY column names over SELECT names. If
    both clauses contain different fields with the same names, a warning is
    issued that name of 'ref' is ambiguous. We extend ANSI SQL in that when no
    GROUP BY column is found, then a HAVING name is resolved as a possibly
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    derived SELECT column. This extension is allowed only if the
    MODE_ONLY_FULL_GROUP_BY sql mode isn't enabled.
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  NOTES
    The resolution procedure is:
    - Search for a column or derived column named col_ref_i [in table T_j]
      in the SELECT clause of Q.
    - Search for a column named col_ref_i [in table T_j]
      in the GROUP BY clause of Q.
    - If found different columns with the same name in GROUP BY and SELECT
      - issue a warning and return the GROUP BY column,
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      - otherwise
        - if the MODE_ONLY_FULL_GROUP_BY mode is enabled return error
        - else return the found SELECT column.
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  RETURN
    NULL - there was an error, and the error was already reported
    not_found_item - the item was not resolved, no error was reported
    resolved item - if the item was resolved
*/

static Item**
resolve_ref_in_select_and_group(THD *thd, Item_ident *ref, SELECT_LEX *select)
{
  Item **group_by_ref= NULL;
  Item **select_ref= NULL;
  ORDER *group_list= (ORDER*) select->group_list.first;
  bool ambiguous_fields= FALSE;
  uint counter;
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  bool not_used;
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  /*
    Search for a column or derived column named as 'ref' in the SELECT
    clause of the current select.
  */
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  if (!(select_ref= find_item_in_list(ref, *(select->get_item_list()),
                                      &counter, REPORT_EXCEPT_NOT_FOUND,
                                      &not_used)))
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    return NULL; /* Some error occurred. */

  /* If this is a non-aggregated field inside HAVING, search in GROUP BY. */
  if (select->having_fix_field && !ref->with_sum_func && group_list)
  {
    group_by_ref= find_field_in_group_list(ref, group_list);
    
    /* Check if the fields found in SELECT and GROUP BY are the same field. */
    if (group_by_ref && (select_ref != not_found_item) &&
        !((*group_by_ref)->eq(*select_ref, 0)))
    {
      ambiguous_fields= TRUE;
      push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN, ER_NON_UNIQ_ERROR,
                          ER(ER_NON_UNIQ_ERROR), ref->full_name(),
                          current_thd->where);

    }
  }

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  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY &&
      select_ref != not_found_item && !group_by_ref)
  {
    /*
      Report the error if fields was found only in the SELECT item list and
      the strict mode is enabled.
    */
    my_error(ER_NON_GROUPING_FIELD_USED, MYF(0),
             ref->name, "HAVING");
    return NULL;
  }
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  if (select_ref != not_found_item || group_by_ref)
  {
    if (select_ref != not_found_item && !ambiguous_fields)
    {
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      DBUG_ASSERT(*select_ref != 0);
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      if (!select->ref_pointer_array[counter])
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      {
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        my_error(ER_ILLEGAL_REFERENCE, MYF(0),
                 ref->name, "forward reference in item list");
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        return NULL;
      }
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      DBUG_ASSERT((*select_ref)->fixed);
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      return (select->ref_pointer_array + counter);
    }
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    if (group_by_ref)
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      return group_by_ref;
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    DBUG_ASSERT(FALSE);
    return NULL; /* So there is no compiler warning. */
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  }
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  return (Item**) not_found_item;
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}


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/*
  Resolve the name of an outer select column reference.

  SYNOPSIS
    Item_field::fix_outer_field()
    thd        [in]      current thread
    from_field [in/out]  found field reference or (Field*)not_found_field
    reference  [in/out]  view column if this item was resolved to a view column

  DESCRIPTION
    The method resolves the column reference represented by 'this' as a column
    present in outer selects that contain current select.

  NOTES
    This is the inner loop of Item_field::fix_fields:

      for each outer query Q_k beginning from the inner-most one
      {
        search for a column or derived column named col_ref_i
        [in table T_j] in the FROM clause of Q_k;

        if such a column is not found
          Search for a column or derived column named col_ref_i
          [in table T_j] in the SELECT and GROUP clauses of Q_k.
      }

  IMPLEMENTATION
    In prepared statements, because of cache, find_field_in_tables()
    can resolve fields even if they don't belong to current context.
    In this case this method only finds appropriate context and marks
    current select as dependent. The found reference of field should be
    provided in 'from_field'.

  RETURN
     1 - column succefully resolved and fix_fields() should continue.
     0 - column fully fixed and fix_fields() should return FALSE
    -1 - error occured
*/
int
Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
{
  enum_parsing_place place= NO_MATTER;
  bool field_found= (*from_field != not_found_field);
  bool upward_lookup= FALSE;

  /*
    If there are outer contexts (outer selects, but current select is
    not derived table or view) try to resolve this reference in the
    outer contexts.

    We treat each subselect as a separate namespace, so that different
    subselects may contain columns with the same names. The subselects
    are searched starting from the innermost.
  */
  Name_resolution_context *last_checked_context= context;
  Item **ref= (Item **) not_found_item;
  Name_resolution_context *outer_context= context->outer_context;
  for (;
       outer_context;
       outer_context= outer_context->outer_context)
  {
    SELECT_LEX *select= outer_context->select_lex;
    Item_subselect *prev_subselect_item=
      last_checked_context->select_lex->master_unit()->item;
    last_checked_context= outer_context;
    upward_lookup= TRUE;

    place= prev_subselect_item->parsing_place;
    /*
      If outer_field is set, field was already found by first call
      to find_field_in_tables(). Only need to find appropriate context.
    */
    if (field_found && outer_context->select_lex !=
        cached_table->select_lex)
      continue;
    /*
      In case of a view, find_field_in_tables() writes the pointer to
      the found view field into '*reference', in other words, it
      substitutes this Item_field with the found expression.
    */
    if (field_found || (*from_field= find_field_in_tables(thd, this,
                                          outer_context->
                                            first_name_resolution_table,
                                          outer_context->
                                            last_name_resolution_table,
                                          reference,
                                          IGNORE_EXCEPT_NON_UNIQUE,
                                          TRUE, TRUE)) !=
        not_found_field)
    {
      if (*from_field)
      {
        if (*from_field != view_ref_found)
        {
          prev_subselect_item->used_tables_cache|= (*from_field)->table->map;
          prev_subselect_item->const_item_cache= 0;
          if (thd->lex->in_sum_func &&
              thd->lex->in_sum_func->nest_level == 
              thd->lex->current_select->nest_level)
          {
            Item::Type type= (*reference)->type();
            set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                          select->nest_level);
            set_field(*from_field);
            fixed= 1;
            mark_as_dependent(thd, last_checked_context->select_lex,
                              context->select_lex, this,
                              ((type == REF_ITEM || type == FIELD_ITEM) ?
                               (Item_ident*) (*reference) : 0));
            return 0;
          }
        }
        else
        {
          Item::Type type= (*reference)->type();
          prev_subselect_item->used_tables_cache|=
            (*reference)->used_tables();
          prev_subselect_item->const_item_cache&=
            (*reference)->const_item();
          mark_as_dependent(thd, last_checked_context->select_lex,
                            context->select_lex, this,
                            ((type == REF_ITEM || type == FIELD_ITEM) ?
                             (Item_ident*) (*reference) :
                             0));
          /*
            A reference to a view field had been found and we
            substituted it instead of this Item (find_field_in_tables
            does it by assigning the new value to *reference), so now
            we can return from this function.
          */
          return 0;
        }
      }
      break;
    }

    /* Search in SELECT and GROUP lists of the outer select. */
    if (outer_context->resolve_in_select_list)
    {
      if (!(ref= resolve_ref_in_select_and_group(thd, this, select)))
        return -1; /* Some error occurred (e.g. ambiguous names). */
      if (ref != not_found_item)
      {
        DBUG_ASSERT(*ref && (*ref)->fixed);
        prev_subselect_item->used_tables_cache|= (*ref)->used_tables();
        prev_subselect_item->const_item_cache&= (*ref)->const_item();
        break;
      }
    }

    /*
      Reference is not found in this select => this subquery depend on
      outer select (or we just trying to find wrong identifier, in this
      case it does not matter which used tables bits we set)
    */
    prev_subselect_item->used_tables_cache|= OUTER_REF_TABLE_BIT;
    prev_subselect_item->const_item_cache= 0;
  }

  DBUG_ASSERT(ref != 0);
  if (!*from_field)
    return -1;
  if (ref == not_found_item && *from_field == not_found_field)
  {
    if (upward_lookup)
    {
      // We can't say exactly what absent table or field
      my_error(ER_BAD_FIELD_ERROR, MYF(0), full_name(), thd->where);
    }
    else
    {
      /* Call find_field_in_tables only to report the error */
      find_field_in_tables(thd, this,
                           context->first_name_resolution_table,
                           context->last_name_resolution_table,
                           reference, REPORT_ALL_ERRORS,
                           !any_privileges &&
                           TRUE, TRUE);
    }
    return -1;
  }
  else if (ref != not_found_item)
  {
    Item *save;
    Item_ref *rf;

    /* Should have been checked in resolve_ref_in_select_and_group(). */
    DBUG_ASSERT(*ref && (*ref)->fixed);
    /*
      Here, a subset of actions performed by Item_ref::set_properties
      is not enough. So we pass ptr to NULL into Item_[direct]_ref
      constructor, so no initialization is performed, and call 
      fix_fields() below.
    */
    save= *ref;
    *ref= NULL;                             // Don't call set_properties()
    rf= (place == IN_HAVING ?
         new Item_ref(context, ref, (char*) table_name,
                      (char*) field_name) :
         new Item_direct_ref(context, ref, (char*) table_name,
                             (char*) field_name));
    *ref= save;
    if (!rf)
      return -1;
    thd->change_item_tree(reference, rf);
    /*
      rf is Item_ref => never substitute other items (in this case)
      during fix_fields() => we can use rf after fix_fields()
    */
    DBUG_ASSERT(!rf->fixed);                // Assured by Item_ref()
    if (rf->fix_fields(thd, reference) || rf->check_cols(1))
      return -1;

    mark_as_dependent(thd, last_checked_context->select_lex,
                      context->select_lex, this,
                      rf);
    return 0;
  }
  else
  {
    mark_as_dependent(thd, last_checked_context->select_lex,
                      context->select_lex,
                      this, this);
    if (last_checked_context->select_lex->having_fix_field)
    {
      Item_ref *rf;
      rf= new Item_ref(context,
                       (cached_table->db[0] ? cached_table->db : 0),
                       (char*) cached_table->alias, (char*) field_name);
      if (!rf)
        return -1;
      thd->change_item_tree(reference, rf);
      /*
        rf is Item_ref => never substitute other items (in this case)
        during fix_fields() => we can use rf after fix_fields()
      */
      DBUG_ASSERT(!rf->fixed);                // Assured by Item_ref()
      if (rf->fix_fields(thd, reference) || rf->check_cols(1))
        return -1;
      return 0;
    }
  }
  return 1;
}


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/*
  Resolve the name of a column reference.

  SYNOPSIS
    Item_field::fix_fields()
    thd       [in]      current thread
    reference [in/out]  view column if this item was resolved to a view column

  DESCRIPTION
    The method resolves the column reference represented by 'this' as a column
    present in one of: FROM clause, SELECT clause, GROUP BY clause of a query
    Q, or in outer queries that contain Q.

  NOTES
    The name resolution algorithm used is (where [T_j] is an optional table
    name that qualifies the column name):

      resolve_column_reference([T_j].col_ref_i)
      {
        search for a column or derived column named col_ref_i
        [in table T_j] in the FROM clause of Q;

        if such a column is NOT found AND    // Lookup in outer queries.
           there are outer queries
        {
          for each outer query Q_k beginning from the inner-most one
          {
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            search for a column or derived column named col_ref_i
            [in table T_j] in the FROM clause of Q_k;
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            if such a column is not found
              Search for a column or derived column named col_ref_i
              [in table T_j] in the SELECT and GROUP clauses of Q_k.
          }
        }
      }

    Notice that compared to Item_ref::fix_fields, here we first search the FROM
    clause, and then we search the SELECT and GROUP BY clauses.

  RETURN
    TRUE  if error
    FALSE on success
*/

3642
bool Item_field::fix_fields(THD *thd, Item **reference)
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{
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  DBUG_ASSERT(fixed == 0);
3645
  if (!field)					// If field is not checked
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  {
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    Field *from_field= (Field *)not_found_field;
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    bool outer_fixed= false;
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    /*
      In case of view, find_field_in_tables() write pointer to view field
      expression to 'reference', i.e. it substitute that expression instead
      of this Item_field
    */
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    if ((from_field= find_field_in_tables(thd, this,
                                          context->first_name_resolution_table,
                                          context->last_name_resolution_table,
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                                          reference,
                                          IGNORE_EXCEPT_NON_UNIQUE,
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                                          !any_privileges,
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                                          TRUE)) ==
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	not_found_field)
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    {
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      int ret;
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      /* Look up in current select's item_list to find aliased fields */
      if (thd->lex->current_select->is_item_list_lookup)
      {
        uint counter;
        bool not_used;
        Item** res= find_item_in_list(this, thd->lex->current_select->item_list,
                                      &counter, REPORT_EXCEPT_NOT_FOUND,
                                      &not_used);
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        if (res != (Item **)not_found_item &&
            (*res)->type() == Item::FIELD_ITEM)
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        {
          set_field((*((Item_field**)res))->field);
          return 0;
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        }
      }
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      if ((ret= fix_outer_field(thd, &from_field, reference)) < 0)
        goto error;
      else if (!ret)
        return FALSE;
      outer_fixed= TRUE;
3684
    }
3685
    else if (!from_field)
3686
      goto error;
3687

bell@sanja.is.com.ua's avatar
VIEW  
bell@sanja.is.com.ua committed
3688 3689 3690 3691
    /*
      if it is not expression from merged VIEW we will set this field.

      We can leave expression substituted from view for next PS/SP rexecution
3692
      (i.e. do not register this substitution for reverting on cleanup()
bell@sanja.is.com.ua's avatar
VIEW  
bell@sanja.is.com.ua committed
3693
      (register_item_tree_changing())), because this subtree will be
3694
      fix_field'ed during setup_tables()->setup_underlying() (i.e. before
bell@sanja.is.com.ua's avatar
VIEW  
bell@sanja.is.com.ua committed
3695 3696 3697 3698 3699
      all other expressions of query, and references on tables which do
      not present in query will not make problems.

      Also we suppose that view can't be changed during PS/SP life.
    */
3700 3701 3702
    if (from_field == view_ref_found)
      return FALSE;

3703
    if (!outer_fixed && cached_table && cached_table->select_lex &&
3704 3705
        context->select_lex &&
        cached_table->select_lex != context->select_lex)
3706 3707 3708 3709
    {
      int ret;
      if ((ret= fix_outer_field(thd, &from_field, reference)) < 0)
        goto error;
3710
      if (!ret)
3711 3712 3713
        return FALSE;
    }

3714
    set_field(from_field);
igor@rurik.mysql.com's avatar
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3715 3716 3717 3718 3719
    if (thd->lex->in_sum_func &&
        thd->lex->in_sum_func->nest_level == 
        thd->lex->current_select->nest_level)
      set_if_bigger(thd->lex->in_sum_func->max_arg_level,
                    thd->lex->current_select->nest_level);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3720
  }
3721
  else if (thd->mark_used_columns != MARK_COLUMNS_NONE)
3722
  {
3723
    TABLE *table= field->table;
3724 3725
    MY_BITMAP *current_bitmap, *other_bitmap;
    if (thd->mark_used_columns == MARK_COLUMNS_READ)
3726
    {
3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742
      current_bitmap= table->read_set;
      other_bitmap=   table->write_set;
    }
    else
    {
      current_bitmap= table->write_set;
      other_bitmap=   table->read_set;
    }
    if (!bitmap_fast_test_and_set(current_bitmap, field->field_index))
    {
      if (!bitmap_is_set(other_bitmap, field->field_index))
      {
        /* First usage of column */
        table->used_fields++;                     // Used to optimize loops
        table->used_keys.intersect(field->part_of_key);
      }
3743
    }
3744
  }
bell@sanja.is.com.ua's avatar
VIEW  
bell@sanja.is.com.ua committed
3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  if (any_privileges)
  {
    char *db, *tab;
    if (cached_table->view)
    {
      db= cached_table->view_db.str;
      tab= cached_table->view_name.str;
    }
    else
    {
      db= cached_table->db;
3757
      tab= cached_table->table_name;
bell@sanja.is.com.ua's avatar
VIEW  
bell@sanja.is.com.ua committed
3758 3759 3760 3761 3762
    }
    if (!(have_privileges= (get_column_grant(thd, &field->table->grant,
                                             db, tab, field_name) &
                            VIEW_ANY_ACL)))
    {
3763
      my_error(ER_COLUMNACCESS_DENIED_ERROR, MYF(0),
3764 3765
               "ANY", thd->security_ctx->priv_user,
               thd->security_ctx->host_or_ip, field_name, tab);
3766
      goto error;
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VIEW  
bell@sanja.is.com.ua committed
3767 3768 3769
    }
  }
#endif
3770
  fixed= 1;
3771
  return FALSE;
3772 3773 3774 3775

error:
  context->process_error(thd);
  return TRUE;
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3776 3777
}

3778 3779 3780 3781 3782 3783 3784 3785

Item *Item_field::safe_charset_converter(CHARSET_INFO *tocs)
{
  no_const_subst= 1;
  return Item::safe_charset_converter(tocs);
}


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3786 3787
void Item_field::cleanup()
{
3788
  DBUG_ENTER("Item_field::cleanup");
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hf@deer.(none) committed
3789
  Item_ident::cleanup();
3790 3791
  /*
    Even if this object was created by direct link to field in setup_wild()
3792
    it will be linked correctly next time by name of field and table alias.
3793 3794
    I.e. we can drop 'field'.
   */
3795
  field= result_field= 0;
3796
  DBUG_VOID_RETURN;
3797
}
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3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818

/*
  Find a field among specified multiple equalities 

  SYNOPSIS
    find_item_equal()
    cond_equal   reference to list of multiple equalities where
                 the field (this object) is to be looked for
  
  DESCRIPTION
    The function first searches the field among multiple equalities
    of the current level (in the cond_equal->current_level list).
    If it fails, it continues searching in upper levels accessed
    through a pointer cond_equal->upper_levels.
    The search terminates as soon as a multiple equality containing 
    the field is found. 

  RETURN VALUES
    First Item_equal containing the field, if success
    0, otherwise
*/
3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840
Item_equal *Item_field::find_item_equal(COND_EQUAL *cond_equal)
{
  Item_equal *item= 0;
  while (cond_equal)
  {
    List_iterator_fast<Item_equal> li(cond_equal->current_level);
    while ((item= li++))
    {
      if (item->contains(field))
        return item;
    }
    /* 
      The field is not found in any of the multiple equalities
      of the current level. Look for it in upper levels
    */
    cond_equal= cond_equal->upper_levels;
  }
  return 0;
}


/*
3841 3842
  Set a pointer to the multiple equality the field reference belongs to
  (if any)
3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864
   
  SYNOPSIS
    equal_fields_propagator()
    arg - reference to list of multiple equalities where
          the field (this object) is to be looked for
  
  DESCRIPTION
    The function looks for a multiple equality containing the field item
    among those referenced by arg.
    In the case such equality exists the function does the following.
    If the found multiple equality contains a constant, then the field
    reference is substituted for this constant, otherwise it sets a pointer
    to the multiple equality in the field item.

  NOTES
    This function is supposed to be called as a callback parameter in calls
    of the transform method.  

  RETURN VALUES
    pointer to the replacing constant item, if the field item was substituted 
    pointer to the field item, otherwise.
*/
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3865

3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880
Item *Item_field::equal_fields_propagator(byte *arg)
{
  if (no_const_subst)
    return this;
  item_equal= find_item_equal((COND_EQUAL *) arg);
  Item *item= 0;
  if (item_equal)
    item= item_equal->get_const();
  if (!item)
    item= this;
  return item;
}


/*
3881 3882 3883 3884
  Mark the item to not be part of substitution if it's not a binary item
  See comments in Arg_comparator::set_compare_func() for details
*/

3885
bool Item_field::set_no_const_sub(byte *arg)
3886 3887 3888
{
  if (field->charset() != &my_charset_bin)
    no_const_subst=1;
3889
  return FALSE;
3890 3891 3892 3893
}


/*
3894
  Replace an Item_field for an equal Item_field that evaluated earlier
3895
  (if any)
3896 3897
   
  SYNOPSIS
3898
    replace_equal_field_()
3899 3900 3901
    arg - a dummy parameter, is not used here
  
  DESCRIPTION
3902 3903 3904 3905 3906
    The function returns a pointer to an item that is taken from
    the very beginning of the item_equal list which the Item_field
    object refers to (belongs to).  
    If the Item_field object does not refer any Item_equal object
    'this' is returned 
3907 3908 3909

  NOTES
    This function is supposed to be called as a callback parameter in calls
3910
    of the thransformer method.  
3911 3912

  RETURN VALUES
3913 3914
    pointer to a replacement Item_field if there is a better equal item;
    this - otherwise.
3915 3916
*/

3917
Item *Item_field::replace_equal_field(byte *arg)
3918 3919 3920 3921
{
  if (item_equal)
  {
    Item_field *subst= item_equal->get_first();
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3922
    if (subst && !field->eq(subst->field))
3923
      return subst;
3924
  }
3925
  return this;
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hf@deer.(none) committed
3926
}
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bk@work.mysql.com committed
3927

3928

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3929 3930
void Item::init_make_field(Send_field *tmp_field,
			   enum enum_field_types field_type)
3931
{
3932
  char *empty_name= (char*) "";
3933
  tmp_field->db_name=		empty_name;
3934 3935 3936 3937
  tmp_field->org_table_name=	empty_name;
  tmp_field->org_col_name=	empty_name;
  tmp_field->table_name=	empty_name;
  tmp_field->col_name=		name;
3938
  tmp_field->charsetnr=         collation.collation->number;
3939 3940 3941
  tmp_field->flags=             (maybe_null ? 0 : NOT_NULL_FLAG) | 
                                (my_binary_compare(collation.collation) ?
                                 BINARY_FLAG : 0);
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3942 3943 3944
  tmp_field->type=field_type;
  tmp_field->length=max_length;
  tmp_field->decimals=decimals;
3945 3946
  if (unsigned_flag)
    tmp_field->flags |= UNSIGNED_FLAG;
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3947 3948
}

3949
void Item::make_field(Send_field *tmp_field)
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bk@work.mysql.com committed
3950
{
3951
  init_make_field(tmp_field, field_type());
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3952 3953 3954
}


3955 3956
void Item_empty_string::make_field(Send_field *tmp_field)
{
3957 3958 3959 3960 3961
  enum_field_types type= FIELD_TYPE_VAR_STRING;
  if (max_length >= 16777216)
    type= FIELD_TYPE_LONG_BLOB;
  else if (max_length >= 65536)
    type= FIELD_TYPE_MEDIUM_BLOB;
3962
  init_make_field(tmp_field, type);
3963 3964
}

3965

3966
enum_field_types Item::field_type() const
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3967
{
3968
  switch (result_type()) {
3969 3970 3971 3972 3973 3974 3975
  case STRING_RESULT:  return MYSQL_TYPE_VARCHAR;
  case INT_RESULT:     return FIELD_TYPE_LONGLONG;
  case DECIMAL_RESULT: return FIELD_TYPE_NEWDECIMAL;
  case REAL_RESULT:    return FIELD_TYPE_DOUBLE;
  case ROW_RESULT:
  default:
    DBUG_ASSERT(0);
3976 3977
    return MYSQL_TYPE_VARCHAR;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3978 3979
}

3980

3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996
/*
  Create a field to hold a string value from an item

  SYNOPSIS
    make_string_field()
    table		Table for which the field is created

  IMPLEMENTATION
    If max_length > CONVERT_IF_BIGGER_TO_BLOB create a blob
    If max_length > 0 create a varchar
    If max_length == 0 create a CHAR(0) 
*/


Field *Item::make_string_field(TABLE *table)
{
3997
  Field *field;
3998 3999
  DBUG_ASSERT(collation.collation);
  if (max_length/collation.collation->mbmaxlen > CONVERT_IF_BIGGER_TO_BLOB)
4000
    field= new Field_blob(max_length, maybe_null, name,
4001
                          collation.collation);
4002
  /* Item_type_holder holds the exact type, do not change it */
4003
  else if (max_length > 0 &&
4004
      (type() != Item::TYPE_HOLDER || field_type() != MYSQL_TYPE_STRING))
4005
    field= new Field_varstring(max_length, maybe_null, name, table->s,
4006
                               collation.collation);
4007 4008 4009 4010 4011 4012
  else
    field= new Field_string(max_length, maybe_null, name,
                            collation.collation);
  if (field)
    field->init(table);
  return field;
4013 4014 4015
}


4016 4017 4018 4019
/*
  Create a field based on field_type of argument

  For now, this is only used to create a field for
4020
  IFNULL(x,something) and time functions
4021 4022 4023 4024 4025 4026

  RETURN
    0  error
    #  Created field
*/

4027
Field *Item::tmp_table_field_from_field_type(TABLE *table, bool fixed_length)
4028
{
4029 4030 4031 4032
  /*
    The field functions defines a field to be not null if null_ptr is not 0
  */
  uchar *null_ptr= maybe_null ? (uchar*) "" : 0;
4033
  Field *field;
4034 4035

  switch (field_type()) {
4036
  case MYSQL_TYPE_DECIMAL:
4037
  case MYSQL_TYPE_NEWDECIMAL:
4038 4039
    field= new Field_new_decimal((char*) 0, max_length, null_ptr, 0,
                                 Field::NONE, name, decimals, 0,
4040
                                 unsigned_flag);
4041
    break;
4042
  case MYSQL_TYPE_TINY:
4043 4044 4045
    field= new Field_tiny((char*) 0, max_length, null_ptr, 0, Field::NONE,
			  name, 0, unsigned_flag);
    break;
4046
  case MYSQL_TYPE_SHORT:
4047 4048 4049
    field= new Field_short((char*) 0, max_length, null_ptr, 0, Field::NONE,
			   name, 0, unsigned_flag);
    break;
4050
  case MYSQL_TYPE_LONG:
4051 4052 4053
    field= new Field_long((char*) 0, max_length, null_ptr, 0, Field::NONE,
			  name, 0, unsigned_flag);
    break;
4054 4055
#ifdef HAVE_LONG_LONG
  case MYSQL_TYPE_LONGLONG:
4056 4057 4058
    field= new Field_longlong((char*) 0, max_length, null_ptr, 0, Field::NONE,
			      name, 0, unsigned_flag);
    break;
4059
#endif
4060
  case MYSQL_TYPE_FLOAT:
4061 4062 4063
    field= new Field_float((char*) 0, max_length, null_ptr, 0, Field::NONE,
			   name, decimals, 0, unsigned_flag);
    break;
4064
  case MYSQL_TYPE_DOUBLE:
4065 4066 4067
    field= new Field_double((char*) 0, max_length, null_ptr, 0, Field::NONE,
			    name, decimals, 0, unsigned_flag);
    break;
4068
  case MYSQL_TYPE_NULL:
4069 4070 4071
    field= new Field_null((char*) 0, max_length, Field::NONE,
			  name, &my_charset_bin);
    break;
4072
  case MYSQL_TYPE_INT24:
4073 4074 4075
    field= new Field_medium((char*) 0, max_length, null_ptr, 0, Field::NONE,
			    name, 0, unsigned_flag);
    break;
4076
  case MYSQL_TYPE_NEWDATE:
4077
  case MYSQL_TYPE_DATE:
4078 4079
    field= new Field_date(maybe_null, name, &my_charset_bin);
    break;
4080
  case MYSQL_TYPE_TIME:
4081 4082
    field= new Field_time(maybe_null, name, &my_charset_bin);
    break;
4083
  case MYSQL_TYPE_TIMESTAMP:
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evgen@sunlight.local committed
4084 4085
    field= new Field_timestamp(maybe_null, name, &my_charset_bin);
    break;
4086
  case MYSQL_TYPE_DATETIME:
4087 4088
    field= new Field_datetime(maybe_null, name, &my_charset_bin);
    break;
4089
  case MYSQL_TYPE_YEAR:
4090 4091 4092
    field= new Field_year((char*) 0, max_length, null_ptr, 0, Field::NONE,
			  name);
    break;
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ramil@mysql.com committed
4093
  case MYSQL_TYPE_BIT:
4094
    field= new Field_bit_as_char(NULL, max_length, null_ptr, 0,
4095 4096
                                 Field::NONE, name);
    break;
4097
  default:
4098
    /* This case should never be chosen */
4099 4100
    DBUG_ASSERT(0);
    /* If something goes awfully wrong, it's better to get a string than die */
4101 4102 4103 4104 4105 4106 4107 4108
  case MYSQL_TYPE_STRING:
    if (fixed_length && max_length < CONVERT_IF_BIGGER_TO_BLOB)
    {
      field= new Field_string(max_length, maybe_null, name,
                              collation.collation);
      break;
    }
    /* Fall through to make_string_field() */
4109 4110
  case MYSQL_TYPE_ENUM:
  case MYSQL_TYPE_SET:
4111
  case MYSQL_TYPE_VAR_STRING:
4112
  case MYSQL_TYPE_VARCHAR:
4113
    return make_string_field(table);
4114 4115 4116 4117 4118
  case MYSQL_TYPE_TINY_BLOB:
  case MYSQL_TYPE_MEDIUM_BLOB:
  case MYSQL_TYPE_LONG_BLOB:
  case MYSQL_TYPE_BLOB:
  case MYSQL_TYPE_GEOMETRY:
4119
    if (this->type() == Item::TYPE_HOLDER)
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evgen@sunlight.local committed
4120 4121
      field= new Field_blob(max_length, maybe_null, name, collation.collation,
                            1);
4122
    else
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evgen@sunlight.local committed
4123
      field= new Field_blob(max_length, maybe_null, name, collation.collation);
4124
    break;					// Blob handled outside of case
4125
  }
4126 4127 4128
  if (field)
    field->init(table);
  return field;
4129 4130
}

4131

4132 4133
/* ARGSUSED */
void Item_field::make_field(Send_field *tmp_field)
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4134
{
4135
  field->make_field(tmp_field);
4136
  DBUG_ASSERT(tmp_field->table_name != 0);
4137 4138
  if (name)
    tmp_field->col_name=name;			// Use user supplied name
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4139 4140
}

4141

bk@work.mysql.com's avatar
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4142
/*
4143
  Set a field:s value from a item
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4144 4145 4146 4147 4148 4149 4150
*/

void Item_field::save_org_in_field(Field *to)
{
  if (field->is_null())
  {
    null_value=1;
4151
    set_field_to_null_with_conversions(to, 1);
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4152 4153 4154 4155 4156 4157 4158 4159 4160
  }
  else
  {
    to->set_notnull();
    field_conv(to,field);
    null_value=0;
  }
}

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4161
int Item_field::save_in_field(Field *to, bool no_conversions)
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4162 4163 4164 4165
{
  if (result_field->is_null())
  {
    null_value=1;
4166
    return set_field_to_null_with_conversions(to, no_conversions);
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4167 4168 4169 4170 4171 4172 4173 4174 4175 4176
  }
  else
  {
    to->set_notnull();
    field_conv(to,result_field);
    null_value=0;
  }
  return 0;
}

4177

monty@hundin.mysql.fi's avatar
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4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193
/*
  Store null in field

  SYNOPSIS
    save_in_field()
    field		Field where we want to store NULL

  DESCRIPTION
    This is used on INSERT.
    Allow NULL to be inserted in timestamp and auto_increment values

  RETURN VALUES
    0	 ok
    1	 Field doesn't support NULL values and can't handle 'field = NULL'
*/   

monty@mashka.mysql.fi's avatar
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4194
int Item_null::save_in_field(Field *field, bool no_conversions)
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monty@hundin.mysql.fi committed
4195
{
4196
  return set_field_to_null_with_conversions(field, no_conversions);
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monty@hundin.mysql.fi committed
4197 4198 4199
}


4200 4201 4202 4203 4204 4205 4206 4207
/*
  Store null in field

  SYNOPSIS
    save_safe_in_field()
    field		Field where we want to store NULL

  RETURN VALUES
4208
    0	 OK
4209 4210 4211
    1	 Field doesn't support NULL values
*/   

monty@hundin.mysql.fi's avatar
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4212
int Item_null::save_safe_in_field(Field *field)
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4213 4214 4215 4216 4217
{
  return set_field_to_null(field);
}


monty@mashka.mysql.fi's avatar
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4218
int Item::save_in_field(Field *field, bool no_conversions)
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4219
{
4220
  int error;
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4221 4222 4223 4224 4225
  if (result_type() == STRING_RESULT ||
      result_type() == REAL_RESULT &&
      field->result_type() == STRING_RESULT)
  {
    String *result;
4226
    CHARSET_INFO *cs= collation.collation;
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bk@work.mysql.com committed
4227
    char buff[MAX_FIELD_WIDTH];		// Alloc buffer for small columns
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4228
    str_value.set_quick(buff, sizeof(buff), cs);
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4229 4230
    result=val_str(&str_value);
    if (null_value)
4231
    {
monty@mysql.com's avatar
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4232
      str_value.set_quick(0, 0, cs);
4233
      return set_field_to_null_with_conversions(field, no_conversions);
4234
    }
4235 4236 4237

    /* NOTE: If null_value == FALSE, "result" must be not NULL.  */

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4238
    field->set_notnull();
4239
    error=field->store(result->ptr(),result->length(),cs);
4240
    str_value.set_quick(0, 0, cs);
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4241 4242 4243
  }
  else if (result_type() == REAL_RESULT)
  {
4244
    double nr= val_real();
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4245 4246 4247
    if (null_value)
      return set_field_to_null(field);
    field->set_notnull();
4248
    error=field->store(nr);
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4249
  }
4250 4251 4252 4253 4254 4255 4256 4257 4258
  else if (result_type() == DECIMAL_RESULT)
  {
    my_decimal decimal_value;
    my_decimal *value= val_decimal(&decimal_value);
    if (null_value)
      return set_field_to_null(field);
    field->set_notnull();
    error=field->store_decimal(value);
  }
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4259 4260 4261 4262
  else
  {
    longlong nr=val_int();
    if (null_value)
4263
      return set_field_to_null_with_conversions(field, no_conversions);
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4264
    field->set_notnull();
4265
    error=field->store(nr, unsigned_flag);
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4266
  }
4267
  return error;
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4268 4269
}

4270

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4271
int Item_string::save_in_field(Field *field, bool no_conversions)
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4272 4273 4274 4275 4276 4277
{
  String *result;
  result=val_str(&str_value);
  if (null_value)
    return set_field_to_null(field);
  field->set_notnull();
4278
  return field->store(result->ptr(),result->length(),collation.collation);
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4279 4280
}

4281

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4282
int Item_uint::save_in_field(Field *field, bool no_conversions)
4283
{
4284
  /* Item_int::save_in_field handles both signed and unsigned. */
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4285
  return Item_int::save_in_field(field, no_conversions);
4286 4287
}

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4288 4289

int Item_int::save_in_field(Field *field, bool no_conversions)
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4290 4291 4292 4293 4294
{
  longlong nr=val_int();
  if (null_value)
    return set_field_to_null(field);
  field->set_notnull();
4295
  return field->store(nr, unsigned_flag);
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4296 4297
}

4298 4299 4300 4301 4302 4303 4304 4305

int Item_decimal::save_in_field(Field *field, bool no_conversions)
{
  field->set_notnull();
  return field->store_decimal(&decimal_value);
}


4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321
bool Item_int::eq(const Item *arg, bool binary_cmp) const
{
  /* No need to check for null value as basic constant can't be NULL */
  if (arg->basic_const_item() && arg->type() == type())
  {
    /*
      We need to cast off const to call val_int(). This should be OK for
      a basic constant.
    */
    Item *item= (Item*) arg;
    return item->val_int() == value && item->unsigned_flag == unsigned_flag;
  }
  return FALSE;
}


4322 4323
Item *Item_int_with_ref::new_item()
{
4324
  DBUG_ASSERT(ref->const_item());
4325 4326 4327 4328 4329 4330 4331 4332 4333 4334
  /*
    We need to evaluate the constant to make sure it works with
    parameter markers.
  */
  return (ref->unsigned_flag ?
          new Item_uint(ref->name, ref->val_int(), ref->max_length) :
          new Item_int(ref->name, ref->val_int(), ref->max_length));
}


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4335 4336
Item_num *Item_uint::neg()
{
4337
  Item_decimal *item= new Item_decimal(value, 1);
4338
  return item->neg();
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4339
}
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4340

4341

4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364
static uint nr_of_decimals(const char *str, const char *end)
{
  const char *decimal_point;

  /* Find position for '.' */
  for (;;)
  {
    if (str == end)
      return 0;
    if (*str == 'e' || *str == 'E')
      return NOT_FIXED_DEC;    
    if (*str++ == '.')
      break;
  }
  decimal_point= str;
  for (; my_isdigit(system_charset_info, *str) ; str++)
    ;
  if (*str == 'e' || *str == 'E')
    return NOT_FIXED_DEC;
  return (uint) (str - decimal_point);
}


4365 4366 4367 4368 4369
/*
  This function is only called during parsing. We will signal an error if
  value is not a true double value (overflow)
*/

4370
Item_float::Item_float(const char *str_arg, uint length)
4371 4372
{
  int error;
4373 4374 4375
  char *end_not_used;
  value= my_strntod(&my_charset_bin, (char*) str_arg, length, &end_not_used,
                    &error);
4376 4377 4378 4379 4380 4381 4382
  if (error)
  {
    /*
      Note that we depend on that str_arg is null terminated, which is true
      when we are in the parser
    */
    DBUG_ASSERT(str_arg[length] == 0);
4383
    my_error(ER_ILLEGAL_VALUE_FOR_TYPE, MYF(0), "double", (char*) str_arg);
4384 4385
  }
  presentation= name=(char*) str_arg;
4386
  decimals=(uint8) nr_of_decimals(str_arg, str_arg+length);
4387 4388 4389 4390 4391
  max_length=length;
  fixed= 1;
}


4392
int Item_float::save_in_field(Field *field, bool no_conversions)
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4393
{
4394
  double nr= val_real();
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4395 4396 4397
  if (null_value)
    return set_field_to_null(field);
  field->set_notnull();
4398
  return field->store(nr);
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4399 4400
}

4401

4402
void Item_float::print(String *str)
4403 4404 4405 4406 4407 4408 4409 4410
{
  if (presentation)
  {
    str->append(presentation);
    return;
  }
  char buffer[20];
  String num(buffer, sizeof(buffer), &my_charset_bin);
4411
  num.set_real(value, decimals, &my_charset_bin);
4412 4413 4414 4415
  str->append(num);
}


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4416 4417 4418 4419 4420
/*
  hex item
  In string context this is a binary string.
  In number context this is a longlong value.
*/
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4421

4422
bool Item_float::eq(const Item *arg, bool binary_cmp) const
4423 4424 4425 4426 4427 4428 4429 4430
{
  if (arg->basic_const_item() && arg->type() == type())
  {
    /*
      We need to cast off const to call val_int(). This should be OK for
      a basic constant.
    */
    Item *item= (Item*) arg;
4431
    return item->val_real() == value;
4432 4433 4434 4435
  }
  return FALSE;
}

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4436

4437
inline uint char_val(char X)
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4438 4439 4440 4441 4442 4443
{
  return (uint) (X >= '0' && X <= '9' ? X-'0' :
		 X >= 'A' && X <= 'Z' ? X-'A'+10 :
		 X-'a'+10);
}

4444

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4445
Item_hex_string::Item_hex_string(const char *str, uint str_length)
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4446 4447 4448 4449 4450 4451
{
  name=(char*) str-2;				// Lex makes this start with 0x
  max_length=(str_length+1)/2;
  char *ptr=(char*) sql_alloc(max_length+1);
  if (!ptr)
    return;
4452
  str_value.set(ptr,max_length,&my_charset_bin);
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4453 4454 4455 4456 4457 4458 4459 4460 4461
  char *end=ptr+max_length;
  if (max_length*2 != str_length)
    *ptr++=char_val(*str++);			// Not even, assume 0 prefix
  while (ptr != end)
  {
    *ptr++= (char) (char_val(str[0])*16+char_val(str[1]));
    str+=2;
  }
  *ptr=0;					// Keep purify happy
4462
  collation.set(&my_charset_bin, DERIVATION_COERCIBLE);
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4463
  fixed= 1;
4464
  unsigned_flag= 1;
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4465 4466
}

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4467
longlong Item_hex_string::val_int()
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4468
{
bell@sanja.is.com.ua's avatar
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4469
  // following assert is redundant, because fixed=1 assigned in constructor
4470
  DBUG_ASSERT(fixed == 1);
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4471 4472 4473 4474 4475 4476 4477 4478 4479 4480
  char *end=(char*) str_value.ptr()+str_value.length(),
       *ptr=end-min(str_value.length(),sizeof(longlong));

  ulonglong value=0;
  for (; ptr != end ; ptr++)
    value=(value << 8)+ (ulonglong) (uchar) *ptr;
  return (longlong) value;
}


4481 4482 4483 4484 4485 4486 4487 4488 4489 4490
my_decimal *Item_hex_string::val_decimal(my_decimal *decimal_value)
{
  // following assert is redundant, because fixed=1 assigned in constructor
  DBUG_ASSERT(fixed == 1);
  ulonglong value= (ulonglong)val_int();
  int2my_decimal(E_DEC_FATAL_ERROR, value, TRUE, decimal_value);
  return (decimal_value);
}


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4491
int Item_hex_string::save_in_field(Field *field, bool no_conversions)
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4492
{
4493
  int error;
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4494 4495 4496
  field->set_notnull();
  if (field->result_type() == STRING_RESULT)
  {
4497
    error=field->store(str_value.ptr(),str_value.length(),collation.collation);
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4498 4499 4500 4501
  }
  else
  {
    longlong nr=val_int();
4502
    error=field->store(nr, TRUE);    // Assume hex numbers are unsigned
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4503
  }
4504
  return error;
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4505 4506 4507
}


4508
bool Item_hex_string::eq(const Item *arg, bool binary_cmp) const
4509 4510 4511 4512 4513 4514 4515 4516 4517 4518
{
  if (arg->basic_const_item() && arg->type() == type())
  {
    if (binary_cmp)
      return !stringcmp(&str_value, &arg->str_value);
    return !sortcmp(&str_value, &arg->str_value, collation.collation);
  }
  return FALSE;
}

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4519

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4520
Item *Item_hex_string::safe_charset_converter(CHARSET_INFO *tocs)
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4521 4522 4523 4524 4525 4526 4527
{
  Item_string *conv;
  String tmp, *str= val_str(&tmp);

  if (!(conv= new Item_string(str->ptr(), str->length(), tocs)))
    return NULL;
  conv->str_value.copy();
4528
  conv->str_value.mark_as_const();
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4529 4530 4531 4532
  return conv;
}


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4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570
/*
  bin item.
  In string context this is a binary string.
  In number context this is a longlong value.
*/
  
Item_bin_string::Item_bin_string(const char *str, uint str_length)
{
  const char *end= str + str_length - 1;
  uchar bits= 0;
  uint power= 1;

  name= (char*) str - 2;
  max_length= (str_length + 7) >> 3;
  char *ptr= (char*) sql_alloc(max_length + 1);
  if (!ptr)
    return;
  str_value.set(ptr, max_length, &my_charset_bin);
  ptr+= max_length - 1;
  ptr[1]= 0;                     // Set end null for string
  for (; end >= str; end--)
  {
    if (power == 256)
    {
      power= 1;
      *ptr--= bits;
      bits= 0;     
    }
    if (*end == '1')
      bits|= power; 
    power<<= 1;
  }
  *ptr= (char) bits;
  collation.set(&my_charset_bin, DERIVATION_COERCIBLE);
  fixed= 1;
}


4571 4572 4573 4574 4575
/*
  Pack data in buffer for sending
*/

bool Item_null::send(Protocol *protocol, String *packet)
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4576
{
4577
  return protocol->store_null();
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4578 4579 4580
}

/*
4581
  This is only called from items that is not of type item_field
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4582 4583
*/

4584
bool Item::send(Protocol *protocol, String *buffer)
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4585
{
4586 4587
  bool result;
  enum_field_types type;
4588
  LINT_INIT(result);                     // Will be set if null_value == 0
4589 4590 4591

  switch ((type=field_type())) {
  default:
4592 4593 4594 4595 4596 4597 4598 4599 4600
  case MYSQL_TYPE_NULL:
  case MYSQL_TYPE_DECIMAL:
  case MYSQL_TYPE_ENUM:
  case MYSQL_TYPE_SET:
  case MYSQL_TYPE_TINY_BLOB:
  case MYSQL_TYPE_MEDIUM_BLOB:
  case MYSQL_TYPE_LONG_BLOB:
  case MYSQL_TYPE_BLOB:
  case MYSQL_TYPE_GEOMETRY:
4601 4602
  case MYSQL_TYPE_STRING:
  case MYSQL_TYPE_VAR_STRING:
4603
  case MYSQL_TYPE_VARCHAR:
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4604
  case MYSQL_TYPE_BIT:
4605
  case MYSQL_TYPE_NEWDECIMAL:
4606 4607 4608
  {
    String *res;
    if ((res=val_str(buffer)))
4609
      result= protocol->store(res->ptr(),res->length(),res->charset());
4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620
    break;
  }
  case MYSQL_TYPE_TINY:
  {
    longlong nr;
    nr= val_int();
    if (!null_value)
      result= protocol->store_tiny(nr);
    break;
  }
  case MYSQL_TYPE_SHORT:
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4621
  case MYSQL_TYPE_YEAR:
4622 4623 4624 4625 4626 4627 4628
  {
    longlong nr;
    nr= val_int();
    if (!null_value)
      result= protocol->store_short(nr);
    break;
  }
4629
  case MYSQL_TYPE_INT24:
4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645
  case MYSQL_TYPE_LONG:
  {
    longlong nr;
    nr= val_int();
    if (!null_value)
      result= protocol->store_long(nr);
    break;
  }
  case MYSQL_TYPE_LONGLONG:
  {
    longlong nr;
    nr= val_int();
    if (!null_value)
      result= protocol->store_longlong(nr, unsigned_flag);
    break;
  }
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4646 4647 4648
  case MYSQL_TYPE_FLOAT:
  {
    float nr;
4649
    nr= (float) val_real();
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4650 4651 4652 4653
    if (!null_value)
      result= protocol->store(nr, decimals, buffer);
    break;
  }
4654 4655
  case MYSQL_TYPE_DOUBLE:
  {
4656
    double nr= val_real();
4657 4658 4659 4660 4661 4662
    if (!null_value)
      result= protocol->store(nr, decimals, buffer);
    break;
  }
  case MYSQL_TYPE_DATETIME:
  case MYSQL_TYPE_DATE:
4663
  case MYSQL_TYPE_TIMESTAMP:
4664 4665
  {
    TIME tm;
4666
    get_date(&tm, TIME_FUZZY_DATE);
4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687
    if (!null_value)
    {
      if (type == MYSQL_TYPE_DATE)
	return protocol->store_date(&tm);
      else
	result= protocol->store(&tm);
    }
    break;
  }
  case MYSQL_TYPE_TIME:
  {
    TIME tm;
    get_time(&tm);
    if (!null_value)
      result= protocol->store_time(&tm);
    break;
  }
  }
  if (null_value)
    result= protocol->store_null();
  return result;
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4688 4689
}

4690 4691

bool Item_field::send(Protocol *protocol, String *buffer)
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4692
{
4693
  return protocol->store(result_field);
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4694 4695
}

4696

4697 4698 4699 4700 4701
Item_ref::Item_ref(Name_resolution_context *context_arg,
                   Item **item, const char *table_name_arg,
                   const char *field_name_arg)
  :Item_ident(context_arg, NullS, table_name_arg, field_name_arg),
   result_field(0), ref(item)
4702 4703 4704 4705
{
  /*
    This constructor used to create some internals references over fixed items
  */
4706
  DBUG_ASSERT(ref != 0);
4707
  if (*ref && (*ref)->fixed)
4708 4709 4710 4711
    set_properties();
}


4712
/*
4713
  Resolve the name of a reference to a column reference.
4714 4715 4716

  SYNOPSIS
    Item_ref::fix_fields()
4717 4718
    thd       [in]      current thread
    reference [in/out]  view column if this item was resolved to a view column
4719 4720

  DESCRIPTION
4721 4722
    The method resolves the column reference represented by 'this' as a column
    present in one of: GROUP BY clause, SELECT clause, outer queries. It is
4723 4724
    used typically for columns in the HAVING clause which are not under
    aggregate functions.
4725 4726

  NOTES
4727 4728
    The name resolution algorithm used is (where [T_j] is an optional table
    name that qualifies the column name):
4729

4730 4731 4732
      resolve_extended([T_j].col_ref_i)
      {
        Search for a column or derived column named col_ref_i [in table T_j]
4733
        in the SELECT and GROUP clauses of Q.
4734

4735 4736
        if such a column is NOT found AND    // Lookup in outer queries.
           there are outer queries
4737 4738 4739
        {
          for each outer query Q_k beginning from the inner-most one
         {
4740 4741 4742 4743 4744 4745 4746 4747
            Search for a column or derived column named col_ref_i
            [in table T_j] in the SELECT and GROUP clauses of Q_k.

            if such a column is not found AND
               - Q_k is not a group query AND
               - Q_k is not inside an aggregate function
               OR
               - Q_(k-1) is not in a HAVING or SELECT clause of Q_k
4748 4749 4750 4751 4752 4753 4754
            {
              search for a column or derived column named col_ref_i
              [in table T_j] in the FROM clause of Q_k;
            }
          }
        }
      }
4755 4756

    This procedure treats GROUP BY and SELECT clauses as one namespace for
4757 4758 4759
    column references in HAVING. Notice that compared to
    Item_field::fix_fields, here we first search the SELECT and GROUP BY
    clauses, and then we search the FROM clause.
4760

4761 4762 4763
  POSTCONDITION
    Item_ref::ref is 0 or points to a valid item

4764 4765 4766 4767
  RETURN
    TRUE  if error
    FALSE on success
*/
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4768

4769
bool Item_ref::fix_fields(THD *thd, Item **reference)
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4770
{
4771
  enum_parsing_place place= NO_MATTER;
4772
  DBUG_ASSERT(fixed == 0);
4773 4774
  SELECT_LEX *current_sel= thd->lex->current_select;

4775
  if (!ref || ref == not_found_item)
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4776
  {
4777 4778 4779
    if (!(ref= resolve_ref_in_select_and_group(thd, this,
                                               context->select_lex)))
      goto error;             /* Some error occurred (e.g. ambiguous names). */
4780

4781
    if (ref == not_found_item) /* This reference was not resolved. */
4782
    {
4783 4784
      Name_resolution_context *last_checked_context= context;
      Name_resolution_context *outer_context= context->outer_context;
4785 4786 4787
      Field *from_field;
      ref= 0;

4788
      if (!outer_context)
4789 4790 4791 4792
      {
        /* The current reference cannot be resolved in this query. */
        my_error(ER_BAD_FIELD_ERROR,MYF(0),
                 this->full_name(), current_thd->where);
4793
        goto error;
4794
      }
4795

4796
      /*
4797 4798 4799
        If there is an outer context (select), and it is not a derived table
        (which do not support the use of outer fields for now), try to
        resolve this reference in the outer select(s).
4800

4801 4802 4803
        We treat each subselect as a separate namespace, so that different
        subselects may contain columns with the same names. The subselects are
        searched starting from the innermost.
4804
      */
4805 4806
      from_field= (Field*) not_found_field;

4807
      do
4808
      {
4809 4810 4811 4812
        SELECT_LEX *select= outer_context->select_lex;
        Item_subselect *prev_subselect_item=
          last_checked_context->select_lex->master_unit()->item;
        last_checked_context= outer_context;
4813

4814
        /* Search in the SELECT and GROUP lists of the outer select. */
4815
        if (outer_context->resolve_in_select_list)
4816
        {
4817 4818
          if (!(ref= resolve_ref_in_select_and_group(thd, this, select)))
            goto error; /* Some error occurred (e.g. ambiguous names). */
4819
          if (ref != not_found_item)
4820
          {
4821 4822 4823 4824
            DBUG_ASSERT(*ref && (*ref)->fixed);
            prev_subselect_item->used_tables_cache|= (*ref)->used_tables();
            prev_subselect_item->const_item_cache&= (*ref)->const_item();
            break;
4825 4826
          }
          /*
4827 4828 4829
            Set ref to 0 to ensure that we get an error in case we replaced
            this item with another item and still use this item in some
            other place of the parse tree.
4830
          */
4831
          ref= 0;
4832
        }
4833

4834 4835 4836 4837 4838
        place= prev_subselect_item->parsing_place;
        /*
          Check table fields only if the subquery is used somewhere out of
          HAVING or the outer SELECT does not use grouping (i.e. tables are
          accessible).
4839
          TODO:
4840 4841 4842 4843 4844 4845
          Here we could first find the field anyway, and then test this
          condition, so that we can give a better error message -
          ER_WRONG_FIELD_WITH_GROUP, instead of the less informative
          ER_BAD_FIELD_ERROR which we produce now.
        */
        if ((place != IN_HAVING ||
4846 4847
             (!select->with_sum_func &&
              select->group_list.elements == 0)))
4848
        {
4849
          /*
4850 4851 4852
            In case of view, find_field_in_tables() write pointer to view
            field expression to 'reference', i.e. it substitute that
            expression instead of this Item_ref
4853
          */
4854
          from_field= find_field_in_tables(thd, this,
4855 4856 4857 4858
                                           outer_context->
                                             first_name_resolution_table,
                                           outer_context->
                                             last_name_resolution_table,
4859 4860
                                           reference,
                                           IGNORE_EXCEPT_NON_UNIQUE,
4861
                                           TRUE, TRUE);
4862
          if (! from_field)
4863
            goto error;
4864
          if (from_field == view_ref_found)
4865
          {
4866 4867 4868 4869 4870 4871
            Item::Type type= (*reference)->type();
            prev_subselect_item->used_tables_cache|=
              (*reference)->used_tables();
            prev_subselect_item->const_item_cache&=
              (*reference)->const_item();
            DBUG_ASSERT((*reference)->type() == REF_ITEM);
4872 4873
            mark_as_dependent(thd, last_checked_context->select_lex,
                              context->select_lex, this,
4874 4875 4876 4877 4878 4879 4880
                              ((type == REF_ITEM || type == FIELD_ITEM) ?
                               (Item_ident*) (*reference) :
                               0));
            /*
              view reference found, we substituted it instead of this
              Item, so can quit
            */
4881 4882
            return FALSE;
          }
4883 4884
          if (from_field != not_found_field)
          {
4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903
            if (cached_table && cached_table->select_lex &&
                outer_context->select_lex &&
                cached_table->select_lex != outer_context->select_lex)
            {
              /*
                Due to cache, find_field_in_tables() can return field which
                doesn't belong to provided outer_context. In this case we have
                to find proper field context in order to fix field correcly.
              */
              do
              {
                outer_context= outer_context->outer_context;
                select= outer_context->select_lex;
                prev_subselect_item=
                  last_checked_context->select_lex->master_unit()->item;
                last_checked_context= outer_context;
              } while (outer_context && outer_context->select_lex &&
                       cached_table->select_lex != outer_context->select_lex);
            }
4904 4905 4906 4907
            prev_subselect_item->used_tables_cache|= from_field->table->map;
            prev_subselect_item->const_item_cache= 0;
            break;
          }
4908
        }
4909 4910 4911 4912 4913 4914
        DBUG_ASSERT(from_field == not_found_field);

        /* Reference is not found => depend on outer (or just error). */
        prev_subselect_item->used_tables_cache|= OUTER_REF_TABLE_BIT;
        prev_subselect_item->const_item_cache= 0;

4915 4916
        outer_context= outer_context->outer_context;
      } while (outer_context);
4917 4918 4919

      DBUG_ASSERT(from_field != 0 && from_field != view_ref_found);
      if (from_field != not_found_field)
4920
      {
4921 4922
        Item_field* fld;
        if (!(fld= new Item_field(from_field)))
4923
          goto error;
4924
        thd->change_item_tree(reference, fld);
4925 4926
        mark_as_dependent(thd, last_checked_context->select_lex,
                          thd->lex->current_select, this, fld);
4927 4928 4929 4930 4931 4932
        return FALSE;
      }
      if (ref == 0)
      {
        /* The item was not a table field and not a reference */
        my_error(ER_BAD_FIELD_ERROR, MYF(0),
4933
                 this->full_name(), current_thd->where);
4934
        goto error;
4935
      }
4936 4937
      /* Should be checked in resolve_ref_in_select_and_group(). */
      DBUG_ASSERT(*ref && (*ref)->fixed);
4938 4939
      mark_as_dependent(thd, last_checked_context->select_lex,
                        context->select_lex, this, this);
4940
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4941
  }
4942

4943
  DBUG_ASSERT(*ref);
4944
  /*
4945 4946 4947
    Check if this is an incorrect reference in a group function or forward
    reference. Do not issue an error if this is an unnamed reference inside an
    aggregate function.
4948
  */
4949
  if (((*ref)->with_sum_func && name &&
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
4950 4951
       !(current_sel->linkage != GLOBAL_OPTIONS_TYPE &&
         current_sel->having_fix_field)) ||
4952 4953
      !(*ref)->fixed)
  {
4954 4955 4956 4957
    my_error(ER_ILLEGAL_REFERENCE, MYF(0),
             name, ((*ref)->with_sum_func?
                    "reference to group function":
                    "forward reference in item list"));
4958
    goto error;
4959
  }
4960 4961 4962

  set_properties();

4963
  if ((*ref)->check_cols(1))
4964
    goto error;
4965
  return FALSE;
4966 4967 4968 4969

error:
  context->process_error(thd);
  return TRUE;
4970 4971
}

4972

4973 4974
void Item_ref::set_properties()
{
4975 4976 4977
  max_length= (*ref)->max_length;
  maybe_null= (*ref)->maybe_null;
  decimals=   (*ref)->decimals;
4978
  collation.set((*ref)->collation);
monty@mysql.com's avatar
monty@mysql.com committed
4979 4980 4981 4982
  /*
    We have to remember if we refer to a sum function, to ensure that
    split_sum_func() doesn't try to change the reference.
  */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4983
  with_sum_func= (*ref)->with_sum_func;
timour@mysql.com's avatar
Merge  
timour@mysql.com committed
4984
  unsigned_flag= (*ref)->unsigned_flag;
4985 4986 4987 4988
  if ((*ref)->type() == FIELD_ITEM)
    alias_name_used= ((Item_ident *) (*ref))->alias_name_used;
  else
    alias_name_used= TRUE; // it is not field, so it is was resolved by alias
4989
  fixed= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4990 4991
}

4992

hf@deer.(none)'s avatar
hf@deer.(none) committed
4993 4994
void Item_ref::cleanup()
{
4995
  DBUG_ENTER("Item_ref::cleanup");
hf@deer.(none)'s avatar
hf@deer.(none) committed
4996
  Item_ident::cleanup();
4997
  result_field= 0;
4998
  DBUG_VOID_RETURN;
hf@deer.(none)'s avatar
hf@deer.(none) committed
4999 5000 5001
}


5002 5003
void Item_ref::print(String *str)
{
5004
  if (ref)
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
5005 5006 5007 5008 5009 5010 5011 5012 5013 5014
  {
    if ((*ref)->type() != Item::CACHE_ITEM && ref_type() != VIEW_REF &&
        name && alias_name_used)
    {
      THD *thd= current_thd;
      append_identifier(thd, str, name, (uint) strlen(name));
    }
    else
      (*ref)->print(str);
  }
5015 5016 5017 5018 5019
  else
    Item_ident::print(str);
}


5020 5021 5022 5023 5024 5025 5026 5027
bool Item_ref::send(Protocol *prot, String *tmp)
{
  if (result_field)
    return prot->store(result_field);
  return (*ref)->send(prot, tmp);
}


5028 5029 5030 5031 5032 5033 5034 5035
double Item_ref::val_result()
{
  if (result_field)
  {
    if ((null_value= result_field->is_null()))
      return 0.0;
    return result_field->val_real();
  }
5036
  return val_real();
5037 5038 5039 5040 5041 5042 5043 5044
}


longlong Item_ref::val_int_result()
{
  if (result_field)
  {
    if ((null_value= result_field->is_null()))
5045
      return 0;
5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064
    return result_field->val_int();
  }
  return val_int();
}


String *Item_ref::str_result(String* str)
{
  if (result_field)
  {
    if ((null_value= result_field->is_null()))
      return 0;
    str->set_charset(str_value.charset());
    return result_field->val_str(str, &str_value);
  }
  return val_str(str);
}


5065 5066 5067 5068 5069 5070 5071 5072 5073 5074 5075 5076 5077 5078 5079 5080 5081 5082
my_decimal *Item_ref::val_decimal_result(my_decimal *decimal_value)
{
  if (result_field)
  {
    if ((null_value= result_field->is_null()))
      return 0;
    return result_field->val_decimal(decimal_value);
  }
  return val_decimal(decimal_value);
}


bool Item_ref::val_bool_result()
{
  if (result_field)
  {
    if ((null_value= result_field->is_null()))
      return 0;
5083
    switch (result_field->result_type()) {
5084
    case INT_RESULT:
5085
      return result_field->val_int() != 0;
5086
    case DECIMAL_RESULT:
5087 5088 5089 5090 5091 5092 5093
    {
      my_decimal decimal_value;
      my_decimal *val= result_field->val_decimal(&decimal_value);
      if (val)
        return !my_decimal_is_zero(val);
      return 0;
    }
5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144
    case REAL_RESULT:
    case STRING_RESULT:
      return result_field->val_real() != 0.0;
    case ROW_RESULT:
    default:
      DBUG_ASSERT(0);
    }
  }
  return val_bool();
}


double Item_ref::val_real()
{
  DBUG_ASSERT(fixed);
  double tmp=(*ref)->val_result();
  null_value=(*ref)->null_value;
  return tmp;
}


longlong Item_ref::val_int()
{
  DBUG_ASSERT(fixed);
  longlong tmp=(*ref)->val_int_result();
  null_value=(*ref)->null_value;
  return tmp;
}


bool Item_ref::val_bool()
{
  DBUG_ASSERT(fixed);
  bool tmp= (*ref)->val_bool_result();
  null_value= (*ref)->null_value;
  return tmp;
}


String *Item_ref::val_str(String* tmp)
{
  DBUG_ASSERT(fixed);
  tmp=(*ref)->str_result(tmp);
  null_value=(*ref)->null_value;
  return tmp;
}


bool Item_ref::is_null()
{
  DBUG_ASSERT(fixed);
5145
  return (*ref)->is_null();
5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156
}


bool Item_ref::get_date(TIME *ltime,uint fuzzydate)
{
  return (null_value=(*ref)->get_date_result(ltime,fuzzydate));
}


my_decimal *Item_ref::val_decimal(my_decimal *decimal_value)
{
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
5157
  my_decimal *val= (*ref)->val_decimal_result(decimal_value);
5158 5159 5160 5161
  null_value= (*ref)->null_value;
  return val;
}

5162 5163 5164
int Item_ref::save_in_field(Field *to, bool no_conversions)
{
  int res;
5165 5166
  if (result_field)
  {
5167 5168 5169 5170 5171
    if (result_field->is_null())
    {
      null_value= 1;
      return set_field_to_null_with_conversions(to, no_conversions);
    }
5172 5173 5174
    to->set_notnull();
    field_conv(to, result_field);
    null_value= 0;
5175 5176 5177 5178 5179 5180 5181
    return 0;
  }
  res= (*ref)->save_in_field(to, no_conversions);
  null_value= (*ref)->null_value;
  return res;
}

5182

5183 5184 5185 5186 5187 5188
void Item_ref::save_org_in_field(Field *field)
{
  (*ref)->save_org_in_field(field);
}


5189 5190 5191 5192 5193 5194 5195 5196 5197 5198
void Item_ref::make_field(Send_field *field)
{
  (*ref)->make_field(field);
  /* Non-zero in case of a view */
  if (name)
    field->col_name= name;
  if (table_name)
    field->table_name= table_name;
  if (db_name)
    field->db_name= db_name;
5199
}
5200 5201


5202 5203
void Item_ref_null_helper::print(String *str)
{
5204
  str->append(STRING_WITH_LEN("<ref_null_helper>("));
5205
  if (ref)
5206 5207 5208 5209 5210 5211 5212
    (*ref)->print(str);
  else
    str->append('?');
  str->append(')');
}


5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254
double Item_direct_ref::val_real()
{
  double tmp=(*ref)->val_real();
  null_value=(*ref)->null_value;
  return tmp;
}


longlong Item_direct_ref::val_int()
{
  longlong tmp=(*ref)->val_int();
  null_value=(*ref)->null_value;
  return tmp;
}


String *Item_direct_ref::val_str(String* tmp)
{
  tmp=(*ref)->val_str(tmp);
  null_value=(*ref)->null_value;
  return tmp;
}


my_decimal *Item_direct_ref::val_decimal(my_decimal *decimal_value)
{
  my_decimal *tmp= (*ref)->val_decimal(decimal_value);
  null_value=(*ref)->null_value;
  return tmp;
}


bool Item_direct_ref::val_bool()
{
  bool tmp= (*ref)->val_bool();
  null_value=(*ref)->null_value;
  return tmp;
}


bool Item_direct_ref::is_null()
{
monty@mysql.com's avatar
monty@mysql.com committed
5255
  return (*ref)->is_null();
5256 5257 5258 5259 5260 5261 5262 5263 5264
}


bool Item_direct_ref::get_date(TIME *ltime,uint fuzzydate)
{
  return (null_value=(*ref)->get_date(ltime,fuzzydate));
}


5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288
/*
  Prepare referenced view viewld then call usual Item_direct_ref::fix_fields

  SYNOPSIS
    Item_direct_view_ref::fix_fields()
    thd         thread handler
    reference   reference on reference where this item stored

  RETURN
    FALSE   OK
    TRUE    Error
*/

bool Item_direct_view_ref::fix_fields(THD *thd, Item **reference)
{
  /* view fild reference must be defined */
  DBUG_ASSERT(*ref);
  /* (*ref)->check_cols() will be made in Item_direct_ref::fix_fields */
  if (!(*ref)->fixed &&
      ((*ref)->fix_fields(thd, ref)))
    return TRUE;
  return Item_direct_ref::fix_fields(thd, reference);
}

5289
/*
5290
  Compare two view column references for equality.
5291 5292 5293 5294 5295 5296 5297

  SYNOPSIS
    Item_direct_view_ref::eq()
    item        item to compare with
    binary_cmp  make binary comparison

  DESCRIPTION
5298 5299
    A view column reference is considered equal to another column
    reference if the second one is a view column and if both column
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
5300 5301
    references resolve to the same item. It is assumed that both
    items are of the same type.
5302 5303 5304 5305 5306 5307 5308 5309 5310

  RETURN
    TRUE    Referenced item is equal to given item
    FALSE   otherwise
*/


bool Item_direct_view_ref::eq(const Item *item, bool binary_cmp) const
{
5311 5312 5313 5314 5315 5316
  if (item->type() == REF_ITEM)
  {
    Item_ref *item_ref= (Item_ref*) item;
    if (item_ref->ref_type() == VIEW_REF)
    {
      Item *item_ref_ref= *(item_ref->ref);
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
5317 5318
      DBUG_ASSERT((*ref)->real_item()->type() == 
                  item_ref_ref->real_item()->type());
5319
      return ((*ref)->real_item() == item_ref_ref->real_item());
5320 5321 5322
    }
  }
  return FALSE;
5323
}
5324

hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5325 5326
bool Item_default_value::eq(const Item *item, bool binary_cmp) const
{
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5327
  return item->type() == DEFAULT_VALUE_ITEM && 
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5328 5329 5330
    ((Item_default_value *)item)->arg->eq(arg, binary_cmp);
}

5331

5332
bool Item_default_value::fix_fields(THD *thd, Item **items)
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5333
{
5334
  Item *real_arg;
5335 5336
  Item_field *field_arg;
  Field *def_field;
5337
  DBUG_ASSERT(fixed == 0);
5338

hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5339
  if (!arg)
5340 5341
  {
    fixed= 1;
5342
    return FALSE;
5343
  }
5344 5345 5346
  if (!arg->fixed && arg->fix_fields(thd, &arg))
    goto error;

5347

5348 5349
  real_arg= arg->real_item();
  if (real_arg->type() != FIELD_ITEM)
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5350
  {
5351
    my_error(ER_NO_DEFAULT_FOR_FIELD, MYF(0), arg->name);
5352
    goto error;
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5353
  }
5354

5355
  field_arg= (Item_field *)real_arg;
5356 5357
  if (field_arg->field->flags & NO_DEFAULT_VALUE_FLAG)
  {
5358
    my_error(ER_NO_DEFAULT_FOR_FIELD, MYF(0), field_arg->field->field_name);
5359
    goto error;
5360 5361
  }
  if (!(def_field= (Field*) sql_alloc(field_arg->field->size_of())))
5362
    goto error;
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5363
  memcpy(def_field, field_arg->field, field_arg->field->size_of());
5364 5365 5366
  def_field->move_field_offset((my_ptrdiff_t)
                               (def_field->table->s->default_values -
                                def_field->table->record[0]));
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5367
  set_field(def_field);
5368
  return FALSE;
5369 5370 5371 5372

error:
  context->process_error(thd);
  return TRUE;
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5373 5374
}

5375

hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5376 5377
void Item_default_value::print(String *str)
{
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5378 5379
  if (!arg)
  {
5380
    str->append(STRING_WITH_LEN("default"));
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5381
    return;
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5382
  }
5383
  str->append(STRING_WITH_LEN("default("));
hf@deer.mysql.r18.ru's avatar
SCRUM  
hf@deer.mysql.r18.ru committed
5384 5385 5386
  arg->print(str);
  str->append(')');
}
5387

5388 5389 5390 5391 5392 5393 5394

int Item_default_value::save_in_field(Field *field_arg, bool no_conversions)
{
  if (!arg)
  {
    if (field_arg->flags & NO_DEFAULT_VALUE_FLAG)
    {
5395 5396
      if (context->error_processor == &view_error_processor)
      {
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5397
        TABLE_LIST *view= cached_table->top_table();
5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412
        push_warning_printf(field_arg->table->in_use,
                            MYSQL_ERROR::WARN_LEVEL_WARN,
                            ER_NO_DEFAULT_FOR_VIEW_FIELD,
                            ER(ER_NO_DEFAULT_FOR_VIEW_FIELD),
                            view->view_db.str,
                            view->view_name.str);
      }
      else
      {
        push_warning_printf(field_arg->table->in_use,
                            MYSQL_ERROR::WARN_LEVEL_WARN,
                            ER_NO_DEFAULT_FOR_FIELD,
                            ER(ER_NO_DEFAULT_FOR_FIELD),
                            field_arg->field_name);
      }
5413 5414 5415 5416 5417 5418 5419 5420 5421
      return 1;
    }
    field_arg->set_default();
    return 0;
  }
  return Item_field::save_in_field(field_arg, no_conversions);
}


5422
/* 
5423 5424
  This method like the walk method traverses the item tree, but at the
  same time it can replace some nodes in the tree
5425
*/ 
5426

5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446
Item *Item_default_value::transform(Item_transformer transformer, byte *args)
{
  DBUG_ASSERT(!current_thd->is_stmt_prepare());

  Item *new_item= arg->transform(transformer, args);
  if (!new_item)
    return 0;

  /*
    THD::change_item_tree() should be called only if the tree was
    really transformed, i.e. when a new item has been created.
    Otherwise we'll be allocating a lot of unnecessary memory for
    change records at each execution.
  */
  if (arg != new_item)
    current_thd->change_item_tree(&arg, new_item);
  return (this->*transformer)(args);
}


5447 5448 5449 5450 5451 5452 5453
bool Item_insert_value::eq(const Item *item, bool binary_cmp) const
{
  return item->type() == INSERT_VALUE_ITEM &&
    ((Item_default_value *)item)->arg->eq(arg, binary_cmp);
}


5454
bool Item_insert_value::fix_fields(THD *thd, Item **items)
5455
{
5456
  DBUG_ASSERT(fixed == 0);
5457
  /* We should only check that arg is in first table */
5458
  if (!arg->fixed)
5459
  {
5460 5461 5462 5463
    bool res;
    st_table_list *orig_next_table= context->last_name_resolution_table;
    context->last_name_resolution_table= context->first_name_resolution_table;
    res= arg->fix_fields(thd, &arg);
5464
    context->last_name_resolution_table= orig_next_table;
5465 5466
    if (res)
      return TRUE;
5467
  }
5468

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  if (arg->type() == REF_ITEM)
  {
    Item_ref *ref= (Item_ref *)arg;
    if (ref->ref[0]->type() != FIELD_ITEM)
    {
5474
      my_error(ER_BAD_FIELD_ERROR, MYF(0), "", "VALUES() function");
5475
      return TRUE;
5476 5477 5478
    }
    arg= ref->ref[0];
  }
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  /*
    According to our SQL grammar, VALUES() function can reference
    only to a column.
  */
  DBUG_ASSERT(arg->type() == FIELD_ITEM);

5485
  Item_field *field_arg= (Item_field *)arg;
5486

5487 5488 5489 5490
  if (field_arg->field->table->insert_values)
  {
    Field *def_field= (Field*) sql_alloc(field_arg->field->size_of());
    if (!def_field)
5491
      return TRUE;
5492
    memcpy(def_field, field_arg->field, field_arg->field->size_of());
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    def_field->move_field_offset((my_ptrdiff_t)
                                 (def_field->table->insert_values -
                                  def_field->table->record[0]));
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    set_field(def_field);
  }
  else
  {
5500
    Field *tmp_field= field_arg->field;
5501
    /* charset doesn't matter here, it's to avoid sigsegv only */
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    tmp_field= new Field_null(0, 0, Field::NONE, field_arg->field->field_name,
                          &my_charset_bin);
    if (tmp_field)
    {
      tmp_field->init(field_arg->field->table);
      set_field(tmp_field);
    }
5509
  }
5510
  return FALSE;
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}

void Item_insert_value::print(String *str)
{
5515
  str->append(STRING_WITH_LEN("values("));
5516 5517 5518 5519
  arg->print(str);
  str->append(')');
}

5520 5521

/*
5522 5523
  Find index of Field object which will be appropriate for item
  representing field of row being changed in trigger.
5524 5525 5526 5527 5528

  SYNOPSIS
    setup_field()
      thd   - current thread context
      table - table of trigger (and where we looking for fields)
5529
      table_grant_info - GRANT_INFO of the subject table
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  NOTE
    This function does almost the same as fix_fields() for Item_field
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    but is invoked right after trigger definition parsing. Since at
    this stage we can't say exactly what Field object (corresponding
    to TABLE::record[0] or TABLE::record[1]) should be bound to this
    Item, we only find out index of the Field and then select concrete
    Field object in fix_fields() (by that time Table_trigger_list::old_field/
    new_field should point to proper array of Fields).
    It also binds Item_trigger_field to Table_triggers_list object for
    table of trigger which uses this item.
5541
*/
5542

5543 5544
void Item_trigger_field::setup_field(THD *thd, TABLE *table,
                                     GRANT_INFO *table_grant_info)
5545
{
5546
  /*
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    It is too early to mark fields used here, because before execution
    of statement that will invoke trigger other statements may use same
    TABLE object, so all such mark-up will be wiped out.
    So instead we do it in Table_triggers_list::mark_fields_used()
    method which is called during execution of these statements.
5552
  */
5553 5554
  enum_mark_columns save_mark_used_columns= thd->mark_used_columns;
  thd->mark_used_columns= MARK_COLUMNS_NONE;
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  /*
    Try to find field by its name and if it will be found
    set field_idx properly.
  */
5559
  (void)find_field_in_table(thd, table, field_name, (uint) strlen(field_name),
5560
                            0, &field_idx);
5561
  thd->mark_used_columns= save_mark_used_columns;
5562
  triggers= table->triggers;
5563
  table_grants= table_grant_info;
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}


bool Item_trigger_field::eq(const Item *item, bool binary_cmp) const
{
  return item->type() == TRIGGER_FIELD_ITEM &&
         row_version == ((Item_trigger_field *)item)->row_version &&
         !my_strcasecmp(system_charset_info, field_name,
                        ((Item_trigger_field *)item)->field_name);
}


5576
void Item_trigger_field::set_required_privilege(bool rw)
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{
  /*
    Require SELECT and UPDATE privilege if this field will be read and
    set, and only UPDATE privilege for setting the field.
  */
  want_privilege= (rw ? SELECT_ACL | UPDATE_ACL : UPDATE_ACL);
}


5586
bool Item_trigger_field::set_value(THD *thd, sp_rcontext */*ctx*/, Item **it)
5587
{
5588
  Item *item= sp_prepare_func_item(thd, it);
5589 5590 5591 5592 5593 5594

  return (!item || (!fixed && fix_fields(thd, 0)) ||
          (item->save_in_field(field, 0) < 0));
}


5595
bool Item_trigger_field::fix_fields(THD *thd, Item **items)
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{
  /*
    Since trigger is object tightly associated with TABLE object most
    of its set up can be performed during trigger loading i.e. trigger
    parsing! So we have little to do in fix_fields. :)
  */
5602

5603
  DBUG_ASSERT(fixed == 0);
5604

5605 5606
  /* Set field. */

5607
  if (field_idx != (uint)-1)
5608
  {
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#ifndef NO_EMBEDDED_ACCESS_CHECKS
    /*
      Check access privileges for the subject table. We check privileges only
      in runtime.
    */

    if (table_grants)
    {
5617
      table_grants->want_privilege= want_privilege;
5618

5619 5620
      if (check_grant_column(thd, table_grants, triggers->table->s->db.str,
                             triggers->table->s->table_name.str, field_name,
5621 5622 5623 5624 5625
                             strlen(field_name), thd->security_ctx))
        return TRUE;
    }
#endif // NO_EMBEDDED_ACCESS_CHECKS

5626 5627
    field= (row_version == OLD_ROW) ? triggers->old_field[field_idx] :
                                      triggers->new_field[field_idx];
5628 5629
    set_field(field);
    fixed= 1;
5630
    return FALSE;
5631 5632 5633 5634
  }

  my_error(ER_BAD_FIELD_ERROR, MYF(0), field_name,
           (row_version == NEW_ROW) ? "NEW" : "OLD");
5635
  return TRUE;
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}


void Item_trigger_field::print(String *str)
{
  str->append((row_version == NEW_ROW) ? "NEW" : "OLD", 3);
  str->append('.');
  str->append(field_name);
}


void Item_trigger_field::cleanup()
{
5649
  want_privilege= original_privilege;
5650 5651 5652 5653 5654 5655 5656 5657
  /*
    Since special nature of Item_trigger_field we should not do most of
    things from Item_field::cleanup() or Item_ident::cleanup() here.
  */
  Item::cleanup();
}


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5658
/*
5659 5660
  If item is a const function, calculate it and return a const item
  The original item is freed if not returned
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*/

Item_result item_cmp_type(Item_result a,Item_result b)
{
  if (a == STRING_RESULT && b == STRING_RESULT)
    return STRING_RESULT;
5667
  if (a == INT_RESULT && b == INT_RESULT)
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5668
    return INT_RESULT;
5669 5670
  else if (a == ROW_RESULT || b == ROW_RESULT)
    return ROW_RESULT;
5671 5672 5673
  if ((a == INT_RESULT || a == DECIMAL_RESULT) &&
      (b == INT_RESULT || b == DECIMAL_RESULT))
    return DECIMAL_RESULT;
5674
  return REAL_RESULT;
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}


5678
void resolve_const_item(THD *thd, Item **ref, Item *comp_item)
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{
5680
  Item *item= *ref;
5681
  Item *new_item= NULL;
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5682
  if (item->basic_const_item())
5683
    return;                                     // Can't be better
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  Item_result res_type=item_cmp_type(comp_item->result_type(),
				     item->result_type());
  char *name=item->name;			// Alloced by sql_alloc

5688
  switch (res_type) {
5689
  case STRING_RESULT:
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5690 5691
  {
    char buff[MAX_FIELD_WIDTH];
5692
    String tmp(buff,sizeof(buff),&my_charset_bin),*result;
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5693 5694
    result=item->val_str(&tmp);
    if (item->null_value)
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      new_item= new Item_null(name);
    else
    {
      uint length= result->length();
      char *tmp_str= sql_strmake(result->ptr(), length);
      new_item= new Item_string(name, tmp_str, length, result->charset());
    }
5702
    break;
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5703
  }
5704
  case INT_RESULT:
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  {
    longlong result=item->val_int();
    uint length=item->max_length;
    bool null_value=item->null_value;
5709 5710
    new_item= (null_value ? (Item*) new Item_null(name) :
               (Item*) new Item_int(name, result, length));
5711
    break;
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5712
  }
5713
  case ROW_RESULT:
5714
  if (item->type() == Item::ROW_ITEM && comp_item->type() == Item::ROW_ITEM)
5715
  {
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    /*
      Substitute constants only in Item_rows. Don't affect other Items
      with ROW_RESULT (eg Item_singlerow_subselect).

      For such Items more optimal is to detect if it is constant and replace
      it with Item_row. This would optimize queries like this:
      SELECT * FROM t1 WHERE (a,b) = (SELECT a,b FROM t2 LIMIT 1);
    */
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    Item_row *item_row= (Item_row*) item;
    Item_row *comp_item_row= (Item_row*) comp_item;
    uint col;
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    new_item= 0;
    /*
      If item and comp_item are both Item_rows and have same number of cols
5730 5731 5732
      then process items in Item_row one by one.
      We can't ignore NULL values here as this item may be used with <=>, in
      which case NULL's are significant.
5733
    */
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    DBUG_ASSERT(item->result_type() == comp_item->result_type());
    DBUG_ASSERT(item_row->cols() == comp_item_row->cols());
    col= item_row->cols();
    while (col-- > 0)
      resolve_const_item(thd, item_row->addr(col), comp_item_row->el(col));
5739
    break;
5740
  }
5741
  /* Fallthrough */
5742
  case REAL_RESULT:
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5743
  {						// It must REAL_RESULT
5744
    double result= item->val_real();
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5745 5746
    uint length=item->max_length,decimals=item->decimals;
    bool null_value=item->null_value;
5747
    new_item= (null_value ? (Item*) new Item_null(name) : (Item*)
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               new Item_float(name, result, decimals, length));
    break;
  }
  case DECIMAL_RESULT:
  {
    my_decimal decimal_value;
    my_decimal *result= item->val_decimal(&decimal_value);
    uint length= item->max_length, decimals= item->decimals;
    bool null_value= item->null_value;
    new_item= (null_value ?
               (Item*) new Item_null(name) :
               (Item*) new Item_decimal(name, result, length, decimals));
    break;
  }
  default:
    DBUG_ASSERT(0);
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5764
  }
5765 5766
  if (new_item)
    thd->change_item_tree(ref, new_item);
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}

/*
  Return true if the value stored in the field is equal to the const item
  We need to use this on the range optimizer because in some cases
  we can't store the value in the field without some precision/character loss.
*/

bool field_is_equal_to_item(Field *field,Item *item)
{

  Item_result res_type=item_cmp_type(field->result_type(),
				     item->result_type());
  if (res_type == STRING_RESULT)
  {
    char item_buff[MAX_FIELD_WIDTH];
    char field_buff[MAX_FIELD_WIDTH];
5784 5785
    String item_tmp(item_buff,sizeof(item_buff),&my_charset_bin),*item_result;
    String field_tmp(field_buff,sizeof(field_buff),&my_charset_bin);
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    item_result=item->val_str(&item_tmp);
    if (item->null_value)
      return 1;					// This must be true
5789
    field->val_str(&field_tmp);
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5790
    return !stringcmp(&field_tmp,item_result);
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5791 5792 5793
  }
  if (res_type == INT_RESULT)
    return 1;					// Both where of type int
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  if (res_type == DECIMAL_RESULT)
  {
    my_decimal item_buf, *item_val,
               field_buf, *field_val;
    item_val= item->val_decimal(&item_buf);
    if (item->null_value)
      return 1;					// This must be true
    field_val= field->val_decimal(&field_buf);
    return !my_decimal_cmp(item_val, field_val);
  }
5804
  double result= item->val_real();
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5805 5806 5807 5808 5809
  if (item->null_value)
    return 1;
  return result == field->val_real();
}

5810 5811
Item_cache* Item_cache::get_cache(Item_result type)
{
5812
  switch (type) {
5813 5814 5815 5816
  case INT_RESULT:
    return new Item_cache_int();
  case REAL_RESULT:
    return new Item_cache_real();
5817 5818
  case DECIMAL_RESULT:
    return new Item_cache_decimal();
5819 5820
  case STRING_RESULT:
    return new Item_cache_str();
5821 5822
  case ROW_RESULT:
    return new Item_cache_row();
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  default:
    // should never be in real life
    DBUG_ASSERT(0);
    return 0;
  }
}

5830 5831 5832

void Item_cache::print(String *str)
{
5833
  str->append(STRING_WITH_LEN("<cache>("));
5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845
  if (example)
    example->print(str);
  else
    Item::print(str);
  str->append(')');
}


void Item_cache_int::store(Item *item)
{
  value= item->val_int_result();
  null_value= item->null_value;
5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862
  unsigned_flag= item->unsigned_flag;
}


String *Item_cache_int::val_str(String *str)
{
  DBUG_ASSERT(fixed == 1);
  str->set(value, default_charset());
  return str;
}


my_decimal *Item_cache_int::val_decimal(my_decimal *decimal_val)
{
  DBUG_ASSERT(fixed == 1);
  int2my_decimal(E_DEC_FATAL_ERROR, value, unsigned_flag, decimal_val);
  return decimal_val;
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}


void Item_cache_real::store(Item *item)
{
  value= item->val_result();
  null_value= item->null_value;
}


5873 5874 5875
longlong Item_cache_real::val_int()
{
  DBUG_ASSERT(fixed == 1);
5876
  return (longlong) rint(value);
5877 5878 5879 5880 5881 5882
}


String* Item_cache_real::val_str(String *str)
{
  DBUG_ASSERT(fixed == 1);
5883
  str->set_real(value, decimals, default_charset());
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  return str;
}


my_decimal *Item_cache_real::val_decimal(my_decimal *decimal_val)
{
  DBUG_ASSERT(fixed == 1);
  double2my_decimal(E_DEC_FATAL_ERROR, value, decimal_val);
  return decimal_val;
}


void Item_cache_decimal::store(Item *item)
{
  my_decimal *val= item->val_decimal_result(&decimal_value);
5899
  if (!(null_value= item->null_value) && val != &decimal_value)
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    my_decimal2decimal(val, &decimal_value);
}

double Item_cache_decimal::val_real()
{
  DBUG_ASSERT(fixed);
  double res;
  my_decimal2double(E_DEC_FATAL_ERROR, &decimal_value, &res);
  return res;
}

longlong Item_cache_decimal::val_int()
{
  DBUG_ASSERT(fixed);
  longlong res;
  my_decimal2int(E_DEC_FATAL_ERROR, &decimal_value, unsigned_flag, &res);
  return res;
}

String* Item_cache_decimal::val_str(String *str)
{
  DBUG_ASSERT(fixed);
  my_decimal_round(E_DEC_FATAL_ERROR, &decimal_value, decimals, FALSE,
                   &decimal_value);
  my_decimal2string(E_DEC_FATAL_ERROR, &decimal_value, 0, 0, 0, str);
  return str;
}

my_decimal *Item_cache_decimal::val_decimal(my_decimal *val)
{
  DBUG_ASSERT(fixed);
  return &decimal_value;
}


5935 5936
void Item_cache_str::store(Item *item)
{
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5937
  value_buff.set(buffer, sizeof(buffer), item->collation.collation);
5938
  value= item->str_result(&value_buff);
5939 5940
  if ((null_value= item->null_value))
    value= 0;
5941
  else if (value != &value_buff)
5942 5943 5944 5945 5946 5947 5948 5949 5950
  {
    /*
      We copy string value to avoid changing value if 'item' is table field
      in queries like following (where t1.c is varchar):
      select a, 
             (select a,b,c from t1 where t1.a=t2.a) = ROW(a,2,'a'),
             (select c from t1 where a=t2.a)
        from t2;
    */
5951 5952
    value_buff.copy(*value);
    value= &value_buff;
5953 5954
  }
}
5955

5956
double Item_cache_str::val_real()
5957 5958
{
  DBUG_ASSERT(fixed == 1);
5959 5960
  int err_not_used;
  char *end_not_used;
5961
  if (value)
5962
    return my_strntod(value->charset(), (char*) value->ptr(),
5963 5964
		      value->length(), &end_not_used, &err_not_used);
  return (double) 0;
5965
}
5966 5967


5968 5969
longlong Item_cache_str::val_int()
{
5970
  DBUG_ASSERT(fixed == 1);
5971
  int err;
5972 5973
  if (value)
    return my_strntoll(value->charset(), value->ptr(),
5974
		       value->length(), 10, (char**) 0, &err);
5975 5976 5977
  else
    return (longlong)0;
}
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5978

5979 5980 5981 5982 5983 5984 5985 5986 5987 5988
my_decimal *Item_cache_str::val_decimal(my_decimal *decimal_val)
{
  DBUG_ASSERT(fixed == 1);
  if (value)
    string2my_decimal(E_DEC_FATAL_ERROR, value, decimal_val);
  else
    decimal_val= 0;
  return decimal_val;
}

5989

5990 5991
bool Item_cache_row::allocate(uint num)
{
5992
  item_count= num;
5993
  THD *thd= current_thd;
5994 5995
  return (!(values= 
	    (Item_cache **) thd->calloc(sizeof(Item_cache *)*item_count)));
5996 5997
}

5998

5999 6000
bool Item_cache_row::setup(Item * item)
{
6001
  example= item;
6002 6003
  if (!values && allocate(item->cols()))
    return 1;
6004
  for (uint i= 0; i < item_count; i++)
6005
  {
6006
    Item *el= item->el(i);
6007 6008
    Item_cache *tmp;
    if (!(tmp= values[i]= Item_cache::get_cache(el->result_type())))
6009
      return 1;
6010
    tmp->setup(el);
6011 6012 6013 6014
  }
  return 0;
}

6015

6016 6017 6018 6019
void Item_cache_row::store(Item * item)
{
  null_value= 0;
  item->bring_value();
6020
  for (uint i= 0; i < item_count; i++)
6021 6022 6023 6024 6025 6026
  {
    values[i]->store(item->el(i));
    null_value|= values[i]->null_value;
  }
}

6027

6028 6029 6030 6031 6032
void Item_cache_row::illegal_method_call(const char *method)
{
  DBUG_ENTER("Item_cache_row::illegal_method_call");
  DBUG_PRINT("error", ("!!! %s method was called for row item", method));
  DBUG_ASSERT(0);
6033
  my_error(ER_OPERAND_COLUMNS, MYF(0), 1);
6034 6035 6036
  DBUG_VOID_RETURN;
}

6037

6038 6039
bool Item_cache_row::check_cols(uint c)
{
6040
  if (c != item_count)
6041
  {
6042
    my_error(ER_OPERAND_COLUMNS, MYF(0), c);
6043 6044 6045 6046 6047
    return 1;
  }
  return 0;
}

6048

6049 6050
bool Item_cache_row::null_inside()
{
6051
  for (uint i= 0; i < item_count; i++)
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  {
    if (values[i]->cols() > 1)
    {
      if (values[i]->null_inside())
	return 1;
    }
    else
    {
      values[i]->val_int();
      if (values[i]->null_value)
	return 1;
    }
  }
  return 0;
}

6068

6069 6070
void Item_cache_row::bring_value()
{
6071
  for (uint i= 0; i < item_count; i++)
6072 6073 6074
    values[i]->bring_value();
  return;
}
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6076

6077 6078
Item_type_holder::Item_type_holder(THD *thd, Item *item)
  :Item(thd, item), enum_set_typelib(0), fld_type(get_real_type(item))
6079 6080
{
  DBUG_ASSERT(item->fixed);
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6081

6082
  max_length= display_length(item);
6083
  maybe_null= item->maybe_null;
6084
  collation.set(item->collation);
6085
  get_full_info(item);
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  /* fix variable decimals which always is NOT_FIXED_DEC */
  if (Field::result_merge_type(fld_type) == INT_RESULT)
    decimals= 0;
6089
  prev_decimal_int_part= item->decimal_int_part();
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}


6093
/*
6094
  Return expression type of Item_type_holder
6095 6096

  SYNOPSIS
6097
    Item_type_holder::result_type()
6098 6099

  RETURN
6100
     Item_result (type of internal MySQL expression result)
6101 6102
*/

6103
Item_result Item_type_holder::result_type() const
6104
{
6105
  return Field::result_merge_type(fld_type);
6106
}
6107

6108

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6109
/*
6110
  Find real field type of item
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6111 6112

  SYNOPSIS
6113
    Item_type_holder::get_real_type()
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6114 6115

  RETURN
6116
    type of field which should be created to store item value
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*/

6119
enum_field_types Item_type_holder::get_real_type(Item *item)
6120
{
6121
  switch(item->type())
6122
  {
6123
  case FIELD_ITEM:
6124
  {
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6125
    /*
6126 6127
      Item_fields::field_type ask Field_type() but sometimes field return
      a different type, like for enum/set, so we need to ask real type.
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    */
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    Field *field= ((Item_field *) item)->field;
    enum_field_types type= field->real_type();
    /* work around about varchar type field detection */
    if (type == MYSQL_TYPE_STRING && field->type() == MYSQL_TYPE_VAR_STRING)
      return MYSQL_TYPE_VAR_STRING;
    return type;
6135
  }
6136
  case SUM_FUNC_ITEM:
6137
  {
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    /*
      Argument of aggregate function sometimes should be asked about field
      type
    */
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    Item_sum *item_sum= (Item_sum *) item;
    if (item_sum->keep_field_type())
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      return get_real_type(item_sum->args[0]);
    break;
  }
  case FUNC_ITEM:
6148
    if (((Item_func *) item)->functype() == Item_func::GUSERVAR_FUNC)
6149
    {
6150
      /*
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        There are work around of problem with changing variable type on the
        fly and variable always report "string" as field type to get
        acceptable information for client in send_field, so we make field
        type from expression type.
6155
      */
6156
      switch (item->result_type()) {
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      case STRING_RESULT:
        return MYSQL_TYPE_VAR_STRING;
      case INT_RESULT:
        return MYSQL_TYPE_LONGLONG;
      case REAL_RESULT:
        return MYSQL_TYPE_DOUBLE;
6163 6164
      case DECIMAL_RESULT:
        return MYSQL_TYPE_NEWDECIMAL;
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      case ROW_RESULT:
      default:
        DBUG_ASSERT(0);
        return MYSQL_TYPE_VAR_STRING;
      }
6170
    }
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    break;
  default:
    break;
6174
  }
6175
  return item->field_type();
6176 6177
}

6178
/*
6179 6180
  Find field type which can carry current Item_type_holder type and
  type of given Item.
6181 6182

  SYNOPSIS
6183 6184 6185
    Item_type_holder::join_types()
    thd     thread handler
    item    given item to join its parameters with this item ones
6186 6187

  RETURN
6188 6189
    TRUE   error - types are incompatible
    FALSE  OK
6190 6191
*/

6192
bool Item_type_holder::join_types(THD *thd, Item *item)
6193
{
6194 6195
  uint max_length_orig= max_length;
  uint decimals_orig= decimals;
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  DBUG_ENTER("Item_type_holder::join_types");
  DBUG_PRINT("info:", ("was type %d len %d, dec %d name %s",
                       fld_type, max_length, decimals,
                       (name ? name : "<NULL>")));
  DBUG_PRINT("info:", ("in type %d len %d, dec %d",
                       get_real_type(item),
                       item->max_length, item->decimals));
6203
  fld_type= Field::field_type_merge(fld_type, get_real_type(item));
6204
  {
6205 6206 6207 6208 6209
    int item_decimals= item->decimals;
    /* fix variable decimals which always is NOT_FIXED_DEC */
    if (Field::result_merge_type(fld_type) == INT_RESULT)
      item_decimals= 0;
    decimals= max(decimals, item_decimals);
6210
  }
6211
  if (Field::result_merge_type(fld_type) == DECIMAL_RESULT)
6212
  {
6213 6214 6215 6216 6217 6218
    decimals= min(max(decimals, item->decimals), DECIMAL_MAX_SCALE);
    int precision= min(max(prev_decimal_int_part, item->decimal_int_part())
                       + decimals, DECIMAL_MAX_PRECISION);
    unsigned_flag&= item->unsigned_flag;
    max_length= my_decimal_precision_to_length(precision, decimals,
                                               unsigned_flag);
6219
  }
6220

6221 6222 6223
  switch (Field::result_merge_type(fld_type))
  {
  case STRING_RESULT:
6224
  {
6225
    const char *old_cs, *old_derivation;
6226
    uint32 old_max_chars= max_length / collation.collation->mbmaxlen;
6227 6228
    old_cs= collation.collation->name;
    old_derivation= collation.derivation_name();
6229
    if (collation.aggregate(item->collation, MY_COLL_ALLOW_CONV))
6230
    {
6231
      my_error(ER_CANT_AGGREGATE_2COLLATIONS, MYF(0),
6232 6233 6234 6235
	       old_cs, old_derivation,
	       item->collation.collation->name,
	       item->collation.derivation_name(),
	       "UNION");
6236
      DBUG_RETURN(TRUE);
6237
    }
6238 6239 6240 6241 6242 6243 6244 6245
    /*
      To figure out max_length, we have to take into account possible
      expansion of the size of the values because of character set
      conversions.
     */
    max_length= max(old_max_chars * collation.collation->mbmaxlen,
                    display_length(item) / item->collation.collation->mbmaxlen *
                    collation.collation->mbmaxlen);
6246
    break;
6247
  }
6248 6249 6250 6251 6252 6253
  case REAL_RESULT:
  {
    if (decimals != NOT_FIXED_DEC)
    {
      int delta1= max_length_orig - decimals_orig;
      int delta2= item->max_length - item->decimals;
6254 6255 6256 6257 6258
      if (fld_type == MYSQL_TYPE_DECIMAL)
        max_length= max(delta1, delta2) + decimals;
      else
        max_length= min(max(delta1, delta2) + decimals,
                        (fld_type == MYSQL_TYPE_FLOAT) ? FLT_DIG+6 : DBL_DIG+7);
6259 6260 6261 6262
    }
    else
      max_length= (fld_type == MYSQL_TYPE_FLOAT) ? FLT_DIG+6 : DBL_DIG+7;
    break;
6263
  }
6264 6265
  default:
    max_length= max(max_length, display_length(item));
6266
  };
6267 6268
  maybe_null|= item->maybe_null;
  get_full_info(item);
6269 6270 6271

  /* Remember decimal integer part to be used in DECIMAL_RESULT handleng */
  prev_decimal_int_part= decimal_int_part();
6272 6273
  DBUG_PRINT("info", ("become type: %d  len: %u  dec: %u",
                      (int) fld_type, max_length, (uint) decimals));
6274
  DBUG_RETURN(FALSE);
6275 6276
}

6277 6278
/*
  Calculate lenth for merging result for given Item type
6279

6280 6281 6282
  SYNOPSIS
    Item_type_holder::real_length()
    item  Item for lrngth detection
6283

6284 6285 6286
  RETURN
    length
*/
6287

6288
uint32 Item_type_holder::display_length(Item *item)
6289 6290
{
  if (item->type() == Item::FIELD_ITEM)
6291
    return ((Item_field *)item)->max_disp_length();
6292

6293
  switch (item->field_type())
6294
  {
6295 6296 6297 6298 6299 6300 6301
  case MYSQL_TYPE_DECIMAL:
  case MYSQL_TYPE_TIMESTAMP:
  case MYSQL_TYPE_DATE:
  case MYSQL_TYPE_TIME:
  case MYSQL_TYPE_DATETIME:
  case MYSQL_TYPE_YEAR:
  case MYSQL_TYPE_NEWDATE:
6302 6303 6304
  case MYSQL_TYPE_VARCHAR:
  case MYSQL_TYPE_BIT:
  case MYSQL_TYPE_NEWDECIMAL:
6305 6306 6307 6308 6309 6310 6311 6312 6313
  case MYSQL_TYPE_ENUM:
  case MYSQL_TYPE_SET:
  case MYSQL_TYPE_TINY_BLOB:
  case MYSQL_TYPE_MEDIUM_BLOB:
  case MYSQL_TYPE_LONG_BLOB:
  case MYSQL_TYPE_BLOB:
  case MYSQL_TYPE_VAR_STRING:
  case MYSQL_TYPE_STRING:
  case MYSQL_TYPE_GEOMETRY:
6314
    return item->max_length;
6315 6316 6317 6318 6319 6320 6321 6322 6323
  case MYSQL_TYPE_TINY:
    return 4;
  case MYSQL_TYPE_SHORT:
    return 6;
  case MYSQL_TYPE_LONG:
    return 11;
  case MYSQL_TYPE_FLOAT:
    return 25;
  case MYSQL_TYPE_DOUBLE:
6324
    return 53;
6325
  case MYSQL_TYPE_NULL:
6326
    return 0;
6327
  case MYSQL_TYPE_LONGLONG:
6328
    return 20;
6329 6330
  case MYSQL_TYPE_INT24:
    return 8;
6331 6332 6333 6334 6335
  default:
    DBUG_ASSERT(0); // we should never go there
    return 0;
  }
}
6336

6337 6338 6339 6340 6341 6342 6343 6344 6345 6346 6347 6348 6349 6350 6351

/*
  Make temporary table field according collected information about type
  of UNION result

  SYNOPSIS
    Item_type_holder::make_field_by_type()
    table  temporary table for which we create fields

  RETURN
    created field
*/

Field *Item_type_holder::make_field_by_type(TABLE *table)
{
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  /*
    The field functions defines a field to be not null if null_ptr is not 0
  */
  uchar *null_ptr= maybe_null ? (uchar*) "" : 0;
6356 6357 6358
  Field *field;

  switch (fld_type) {
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6359
  case MYSQL_TYPE_ENUM:
6360
    DBUG_ASSERT(enum_set_typelib);
6361
    field= new Field_enum((char *) 0, max_length, null_ptr, 0,
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6362
                          Field::NONE, name,
6363
                          get_enum_pack_length(enum_set_typelib->count),
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6364
                          enum_set_typelib, collation.collation);
6365 6366 6367
    if (field)
      field->init(table);
    return field;
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  case MYSQL_TYPE_SET:
    DBUG_ASSERT(enum_set_typelib);
6370
    field= new Field_set((char *) 0, max_length, null_ptr, 0,
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6371
                         Field::NONE, name,
6372
                         get_set_pack_length(enum_set_typelib->count),
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6373
                         enum_set_typelib, collation.collation);
6374 6375 6376
    if (field)
      field->init(table);
    return field;
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  default:
    break;
6379
  }
6380
  return tmp_table_field_from_field_type(table, 0);
6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396
}


/*
  Get full information from Item about enum/set fields to be able to create
  them later

  SYNOPSIS
    Item_type_holder::get_full_info
    item    Item for information collection
*/
void Item_type_holder::get_full_info(Item *item)
{
  if (fld_type == MYSQL_TYPE_ENUM ||
      fld_type == MYSQL_TYPE_SET)
  {
6397 6398 6399 6400
    if (item->type() == Item::SUM_FUNC_ITEM &&
        (((Item_sum*)item)->sum_func() == Item_sum::MAX_FUNC ||
         ((Item_sum*)item)->sum_func() == Item_sum::MIN_FUNC))
      item = ((Item_sum*)item)->args[0];
6401
    /*
6402 6403
      We can have enum/set type after merging only if we have one enum|set
      field (or MIN|MAX(enum|set field)) and number of NULL fields
6404 6405 6406 6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419
    */
    DBUG_ASSERT((enum_set_typelib &&
                 get_real_type(item) == MYSQL_TYPE_NULL) ||
                (!enum_set_typelib &&
                 item->type() == Item::FIELD_ITEM &&
                 (get_real_type(item) == MYSQL_TYPE_ENUM ||
                  get_real_type(item) == MYSQL_TYPE_SET) &&
                 ((Field_enum*)((Item_field *) item)->field)->typelib));
    if (!enum_set_typelib)
    {
      enum_set_typelib= ((Field_enum*)((Item_field *) item)->field)->typelib;
    }
  }
}


6420
double Item_type_holder::val_real()
6421 6422 6423 6424 6425 6426 6427 6428 6429 6430 6431 6432
{
  DBUG_ASSERT(0); // should never be called
  return 0.0;
}


longlong Item_type_holder::val_int()
{
  DBUG_ASSERT(0); // should never be called
  return 0;
}

6433 6434 6435 6436 6437
my_decimal *Item_type_holder::val_decimal(my_decimal *)
{
  DBUG_ASSERT(0); // should never be called
  return 0;
}
6438 6439 6440 6441 6442 6443 6444

String *Item_type_holder::val_str(String*)
{
  DBUG_ASSERT(0); // should never be called
  return 0;
}

6445 6446 6447 6448 6449 6450 6451 6452
void Item_result_field::cleanup()
{
  DBUG_ENTER("Item_result_field::cleanup()");
  Item::cleanup();
  result_field= 0;
  DBUG_VOID_RETURN;
}

6453 6454 6455 6456 6457 6458 6459 6460 6461 6462 6463 6464 6465 6466 6467 6468 6469 6470 6471 6472 6473 6474 6475 6476 6477 6478 6479 6480
/*
  Dummy error processor used by default by Name_resolution_context

  SYNOPSIS
    dummy_error_processor()

  NOTE
    do nothing
*/

void dummy_error_processor(THD *thd, void *data)
{}

/*
  Wrapper of hide_view_error call for Name_resolution_context error processor

  SYNOPSIS
    view_error_processor()

  NOTE
    hide view underlying tables details in error messages
*/

void view_error_processor(THD *thd, void *data)
{
  ((TABLE_LIST *)data)->hide_view_error(thd);
}

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6481 6482 6483 6484
/*****************************************************************************
** Instantiate templates
*****************************************************************************/

6485
#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
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6486 6487
template class List<Item>;
template class List_iterator<Item>;
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6488
template class List_iterator_fast<Item>;
6489
template class List_iterator_fast<Item_field>;
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6490 6491
template class List<List_item>;
#endif