item_cmpfunc.cc 116 KB
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/* Copyright (C) 2000-2006 MySQL 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
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   the Free Software Foundation; version 2 of the License.
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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 */


/* This file defines all compare functions */

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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>
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#include "sql_select.h"
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static bool convert_constant_item(THD *thd, Field *field, Item **item);

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static Item_result item_store_type(Item_result a, Item *item,
                                   my_bool unsigned_flag)
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{
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  Item_result b= item->result_type();

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  if (a == STRING_RESULT || b == STRING_RESULT)
    return STRING_RESULT;
  else if (a == REAL_RESULT || b == REAL_RESULT)
    return REAL_RESULT;
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  else if (a == DECIMAL_RESULT || b == DECIMAL_RESULT ||
           unsigned_flag != item->unsigned_flag)
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    return DECIMAL_RESULT;
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  else
    return INT_RESULT;
}

static void agg_result_type(Item_result *type, Item **items, uint nitems)
{
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  Item **item, **item_end;
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  my_bool unsigned_flag= 0;
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  *type= STRING_RESULT;
  /* Skip beginning NULL items */
  for (item= items, item_end= item + nitems; item < item_end; item++)
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  {
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    if ((*item)->type() != Item::NULL_ITEM)
    {
      *type= (*item)->result_type();
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      unsigned_flag= (*item)->unsigned_flag;
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      item++;
      break;
    }
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  }
  /* Combine result types. Note: NULL items don't affect the result */
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  for (; item < item_end; item++)
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  {
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    if ((*item)->type() != Item::NULL_ITEM)
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      *type= item_store_type(*type, *item, unsigned_flag);
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  }
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}

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/*
  Compare row signature of two expressions

  SYNOPSIS:
    cmp_row_type()
    item1          the first expression
    item2         the second expression

  DESCRIPTION
    The function checks that two expressions have compatible row signatures
    i.e. that the number of columns they return are the same and that if they
    are both row expressions then each component from the first expression has 
    a row signature compatible with the signature of the corresponding component
    of the second expression.

  RETURN VALUES
    1  type incompatibility has been detected
    0  otherwise
*/

static int cmp_row_type(Item* item1, Item* item2)
{
  uint n= item1->cols();
  if (item2->check_cols(n))
    return 1;
  for (uint i=0; i<n; i++)
  {
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    if (item2->element_index(i)->check_cols(item1->element_index(i)->cols()) ||
        (item1->element_index(i)->result_type() == ROW_RESULT &&
         cmp_row_type(item1->element_index(i), item2->element_index(i))))
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      return 1;
  }
  return 0;
}


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/*
  Aggregates result types from the array of items.

  SYNOPSIS:
    agg_cmp_type()
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    thd          thread handle
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    type   [out] the aggregated type
    items        array of items to aggregate the type from
    nitems       number of items in the array

  DESCRIPTION
    This function aggregates result types from the array of items. Found type
    supposed to be used later for comparison of values of these items.
    Aggregation itself is performed by the item_cmp_type() function.
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    The function also checks compatibility of row signatures for the
    submitted items (see the spec for the cmp_row_type function). 

  RETURN VALUES
    1  type incompatibility has been detected
    0  otherwise
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*/

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static int agg_cmp_type(THD *thd, Item_result *type, Item **items, uint nitems)
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{
  uint i;
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  type[0]= items[0]->result_type();
  for (i= 1 ; i < nitems ; i++)
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  {
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    type[0]= item_cmp_type(type[0], items[i]->result_type());
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    /*
      When aggregating types of two row expressions we have to check
      that they have the same cardinality and that each component
      of the first row expression has a compatible row signature with
      the signature of the corresponding component of the second row
      expression.
    */ 
    if (type[0] == ROW_RESULT && cmp_row_type(items[0], items[i]))
      return 1;     // error found: invalid usage of rows
  }
  return 0;
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}

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

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Item_bool_func2* Eq_creator::create(Item *a, Item *b) const
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{
  return new Item_func_eq(a, b);
}
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Item_bool_func2* Ne_creator::create(Item *a, Item *b) const
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{
  return new Item_func_ne(a, b);
}
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Item_bool_func2* Gt_creator::create(Item *a, Item *b) const
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{
  return new Item_func_gt(a, b);
}
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Item_bool_func2* Lt_creator::create(Item *a, Item *b) const
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{
  return new Item_func_lt(a, b);
}
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Item_bool_func2* Ge_creator::create(Item *a, Item *b) const
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{
  return new Item_func_ge(a, b);
}
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Item_bool_func2* Le_creator::create(Item *a, Item *b) const
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{
  return new Item_func_le(a, b);
}
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/*
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  Test functions
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  Most of these  returns 0LL if false and 1LL if true and
  NULL if some arg is NULL.
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*/

longlong Item_func_not::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  bool value= args[0]->val_bool();
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  null_value=args[0]->null_value;
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  return ((!null_value && value == 0) ? 1 : 0);
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}

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/*
  We put any NOT expression into parenthesis to avoid
  possible problems with internal view representations where
  any '!' is converted to NOT. It may cause a problem if
  '!' is used in an expression together with other operators
  whose precedence is lower than the precedence of '!' yet
  higher than the precedence of NOT.
*/

void Item_func_not::print(String *str)
{
  str->append('(');
  Item_func::print(str);
  str->append(')');
}

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/*
  special NOT for ALL subquery
*/

longlong Item_func_not_all::val_int()
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{
  DBUG_ASSERT(fixed == 1);
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  bool value= args[0]->val_bool();
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  /*
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    return TRUE if there was records in underlying select in max/min
    optimization (ALL subquery)
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  */
  if (empty_underlying_subquery())
    return 1;

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  null_value= args[0]->null_value;
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  return ((!null_value && value == 0) ? 1 : 0);
}


bool Item_func_not_all::empty_underlying_subquery()
{
  return ((test_sum_item && !test_sum_item->any_value()) ||
          (test_sub_item && !test_sub_item->any_value()));
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}

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void Item_func_not_all::print(String *str)
{
  if (show)
    Item_func::print(str);
  else
    args[0]->print(str);
}

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/*
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  Special NOP (No OPeration) for ALL subquery it is like  Item_func_not_all
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  (return TRUE if underlying subquery do not return rows) but if subquery
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  returns some rows it return same value as argument (TRUE/FALSE).
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*/

longlong Item_func_nop_all::val_int()
{
  DBUG_ASSERT(fixed == 1);
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  longlong value= args[0]->val_int();
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  /*
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    return FALSE if there was records in underlying select in max/min
    optimization (SAME/ANY subquery)
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  */
  if (empty_underlying_subquery())
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    return 0;
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  null_value= args[0]->null_value;
  return (null_value || value == 0) ? 0 : 1;
}


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/*
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  Convert a constant item to an int and replace the original item

  SYNOPSIS
    convert_constant_item()
    thd             thread handle
    field           item will be converted using the type of this field
    item  [in/out]  reference to the item to convert

  DESCRIPTION
    The function converts a constant expression or string to an integer.
    On successful conversion the original item is substituted for the
    result of the item evaluation.
    This is done when comparing DATE/TIME of different formats and
    also when comparing bigint to strings (in which case strings
    are converted to bigints).

  NOTES
    This function is called only at prepare stage.
    As all derived tables are filled only after all derived tables
    are prepared we do not evaluate items with subselects here because
    they can contain derived tables and thus we may attempt to use a
    table that has not been populated yet.
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  RESULT VALUES
  0	Can't convert item
  1	Item was replaced with an integer version of the item
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*/
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static bool convert_constant_item(THD *thd, Field *field, Item **item)
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{
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  if (!(*item)->with_subselect && (*item)->const_item())
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  {
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    /* For comparison purposes allow invalid dates like 2000-01-32 */
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    ulong orig_sql_mode= thd->variables.sql_mode;
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    thd->variables.sql_mode= (orig_sql_mode & ~MODE_NO_ZERO_DATE) | 
                             MODE_INVALID_DATES;
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    if (!(*item)->save_in_field(field, 1) && !((*item)->null_value))
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    {
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      Item *tmp=new Item_int_with_ref(field->val_int(), *item,
                                      test(field->flags & UNSIGNED_FLAG));
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      thd->variables.sql_mode= orig_sql_mode;
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      if (tmp)
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        thd->change_item_tree(item, tmp);
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      return 1;					// Item was replaced
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    }
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    thd->variables.sql_mode= orig_sql_mode;
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  }
  return 0;
}

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void Item_bool_func2::fix_length_and_dec()
{
  max_length= 1;				     // Function returns 0 or 1
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  THD *thd;
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  /*
    As some compare functions are generated after sql_yacc,
    we have to check for out of memory conditions here
  */
  if (!args[0] || !args[1])
    return;
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  /* 
    We allow to convert to Unicode character sets in some cases.
    The conditions when conversion is possible are:
    - arguments A and B have different charsets
    - A wins according to coercibility rules
    - character set of A is superset for character set of B
   
    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.
  */

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  DTCollation coll;
  if (args[0]->result_type() == STRING_RESULT &&
      args[1]->result_type() == STRING_RESULT &&
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      agg_arg_charsets(coll, args, 2, MY_COLL_CMP_CONV, 1))
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    return;
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  args[0]->cmp_context= args[1]->cmp_context=
    item_cmp_type(args[0]->result_type(), args[1]->result_type());
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  // Make a special case of compare with fields to get nicer DATE comparisons
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  if (functype() == LIKE_FUNC)  // Disable conversion in case of LIKE function.
  {
    set_cmp_func();
    return;
  }
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  thd= current_thd;
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  if (!thd->is_context_analysis_only())
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  {
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    Item *arg_real_item= args[0]->real_item();
    if (arg_real_item->type() == FIELD_ITEM)
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    {
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      Field *field=((Item_field*) arg_real_item)->field;
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      if (field->can_be_compared_as_longlong() &&
          !(arg_real_item->is_datetime() &&
            args[1]->result_type() == STRING_RESULT))
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      {
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        if (convert_constant_item(thd, field,&args[1]))
        {
          cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
                           INT_RESULT);		// Works for all types.
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          args[0]->cmp_context= args[1]->cmp_context= INT_RESULT;
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          return;
        }
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      }
    }
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    arg_real_item= args[1]->real_item();
    if (arg_real_item->type() == FIELD_ITEM)
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    {
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      Field *field=((Item_field*) arg_real_item)->field;
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      if (field->can_be_compared_as_longlong() &&
          !(arg_real_item->is_datetime() &&
            args[0]->result_type() == STRING_RESULT))
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      {
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        if (convert_constant_item(thd, field,&args[0]))
        {
          cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
                           INT_RESULT); // Works for all types.
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          args[0]->cmp_context= args[1]->cmp_context= INT_RESULT;
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          return;
        }
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      }
    }
  }
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  set_cmp_func();
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}

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int Arg_comparator::set_compare_func(Item_bool_func2 *item, Item_result type)
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{
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  owner= item;
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  func= comparator_matrix[type]
                         [test(owner->functype() == Item_func::EQUAL_FUNC)];
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  switch (type) {
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  case ROW_RESULT:
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  {
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    uint n= (*a)->cols();
    if (n != (*b)->cols())
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    {
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      my_error(ER_OPERAND_COLUMNS, MYF(0), n);
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      comparators= 0;
      return 1;
    }
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    if (!(comparators= new Arg_comparator[n]))
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      return 1;
    for (uint i=0; i < n; i++)
    {
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      if ((*a)->element_index(i)->cols() != (*b)->element_index(i)->cols())
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      {
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	my_error(ER_OPERAND_COLUMNS, MYF(0), (*a)->element_index(i)->cols());
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	return 1;
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      }
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      comparators[i].set_cmp_func(owner, (*a)->addr(i), (*b)->addr(i));
    }
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    break;
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  }
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  case STRING_RESULT:
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  {
    /*
      We must set cmp_charset here as we may be called from for an automatic
      generated item, like in natural join
    */
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    if (cmp_collation.set((*a)->collation, (*b)->collation) || 
	cmp_collation.derivation == DERIVATION_NONE)
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    {
      my_coll_agg_error((*a)->collation, (*b)->collation, owner->func_name());
      return 1;
    }
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    if (cmp_collation.collation == &my_charset_bin)
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    {
      /*
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	We are using BLOB/BINARY/VARBINARY, change to compare byte by byte,
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	without removing end space
      */
      if (func == &Arg_comparator::compare_string)
	func= &Arg_comparator::compare_binary_string;
      else if (func == &Arg_comparator::compare_e_string)
	func= &Arg_comparator::compare_e_binary_string;
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      /*
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        As this is binary compassion, mark all fields that they can't be
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        transformed. Otherwise we would get into trouble with comparisons
        like:
        WHERE col= 'j' AND col LIKE BINARY 'j'
        which would be transformed to:
        WHERE col= 'j'
      */
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      (*a)->walk(&Item::set_no_const_sub, (byte*) 0);
      (*b)->walk(&Item::set_no_const_sub, (byte*) 0);
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    }
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    break;
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  }
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  case INT_RESULT:
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  {
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    if (func == &Arg_comparator::compare_int_signed)
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    {
      if ((*a)->unsigned_flag)
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        func= (((*b)->unsigned_flag)?
               &Arg_comparator::compare_int_unsigned :
               &Arg_comparator::compare_int_unsigned_signed);
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      else if ((*b)->unsigned_flag)
        func= &Arg_comparator::compare_int_signed_unsigned;
    }
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    else if (func== &Arg_comparator::compare_e_int)
    {
      if ((*a)->unsigned_flag ^ (*b)->unsigned_flag)
        func= &Arg_comparator::compare_e_int_diff_signedness;
    }
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    break;
  }
  case DECIMAL_RESULT:
    break;
  case REAL_RESULT:
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  {
    if ((*a)->decimals < NOT_FIXED_DEC && (*b)->decimals < NOT_FIXED_DEC)
    {
      precision= 5 * log_01[max((*a)->decimals, (*b)->decimals)];
      if (func == &Arg_comparator::compare_real)
        func= &Arg_comparator::compare_real_fixed;
      else if (func == &Arg_comparator::compare_e_real)
        func= &Arg_comparator::compare_e_real_fixed;
    }
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    break;
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  }
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  default:
    DBUG_ASSERT(0);
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  }
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  return 0;
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}
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/*
  Convert date provided in a string to the int representation.

  SYNOPSIS
    get_date_from_str()
    thd              Thread handle
    str              a string to convert
    warn_type        type of the timestamp for issuing the warning
    warn_name        field name for issuing the warning
    error_arg  [out] TRUE if string isn't a DATETIME or clipping occur

  DESCRIPTION
    Convert date provided in the string str to the int representation.
    if the string contains wrong date or doesn't contain it at all
    then the warning is issued and TRUE returned in the error_arg argument.
    The warn_type and the warn_name arguments are used as the name and the
    type of the field when issuing the warning.

  RETURN
    converted value.
*/

static ulonglong
get_date_from_str(THD *thd, String *str, timestamp_type warn_type,
                  char *warn_name, bool *error_arg)
{
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  ulonglong value= 0;
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  int error;
  MYSQL_TIME l_time;
  enum_mysql_timestamp_type ret;
  *error_arg= TRUE;

  ret= str_to_datetime(str->ptr(), str->length(), &l_time,
                       (TIME_FUZZY_DATE | MODE_INVALID_DATES |
                        (thd->variables.sql_mode &
                         (MODE_NO_ZERO_IN_DATE | MODE_NO_ZERO_DATE))),
                       &error);
  if ((ret == MYSQL_TIMESTAMP_DATETIME || ret == MYSQL_TIMESTAMP_DATE))
  {
    value= TIME_to_ulonglong_datetime(&l_time);
    *error_arg= FALSE;
  }

  if (error || *error_arg)
  {
    make_truncated_value_warning(thd, str->ptr(), str->length(), warn_type,
                                 warn_name);
    *error_arg= TRUE;
  }
  return value;
}


/*
  Check whether compare_datetime() can be used to compare items.

  SYNOPSIS
    Arg_comparator::can_compare_as_dates()
    a, b          [in]  items to be compared
    const_value   [out] converted value of the string constant, if any

  DESCRIPTION
    Check several cases when the DATE/DATETIME comparator should be used.
    The following cases are checked:
      1. Both a and b is a DATE/DATETIME field/function returning string or
         int result.
      2. Only a or b is a DATE/DATETIME field/function returning string or
         int result and the other item (b or a) is an item with string result.
         If the second item is a constant one then it's checked to be
         convertible to the DATE/DATETIME type. If the constant can't be
         converted to a DATE/DATETIME then the compare_datetime() comparator
         isn't used and the warning about wrong DATE/DATETIME value is issued.
      In all other cases (date-[int|real|decimal]/[int|real|decimal]-date)
      the comparison is handled by other comparators.
    If the datetime comparator can be used and one the operands of the
    comparison is a string constant that was successfully converted to a
    DATE/DATETIME type then the result of the conversion is returned in the
    const_value if it is provided.  If there is no constant or
    compare_datetime() isn't applicable then the *const_value remains
    unchanged.

  RETURN
    the found type of date comparison
*/

enum Arg_comparator::enum_date_cmp_type
Arg_comparator::can_compare_as_dates(Item *a, Item *b, ulonglong *const_value)
{
  enum enum_date_cmp_type cmp_type= CMP_DATE_DFLT;
  Item *str_arg= 0, *date_arg= 0;

  if (a->type() == Item::ROW_ITEM || b->type() == Item::ROW_ITEM)
    return CMP_DATE_DFLT;

  if (a->is_datetime())
  {
    if (b->is_datetime())
      cmp_type= CMP_DATE_WITH_DATE;
    else if (b->result_type() == STRING_RESULT)
    {
      cmp_type= CMP_DATE_WITH_STR;
      date_arg= a;
      str_arg= b;
    }
  }
  else if (b->is_datetime() && a->result_type() == STRING_RESULT)
  {
    cmp_type= CMP_STR_WITH_DATE;
    date_arg= b;
    str_arg= a;
  }

  if (cmp_type != CMP_DATE_DFLT)
  {
    if (cmp_type != CMP_DATE_WITH_DATE && str_arg->const_item())
    {
      THD *thd= current_thd;
      ulonglong value;
      bool error;
      String tmp, *str_val= 0;
      timestamp_type t_type= (date_arg->field_type() == MYSQL_TYPE_DATE ?
                              MYSQL_TIMESTAMP_DATE : MYSQL_TIMESTAMP_DATETIME);

      str_val= str_arg->val_str(&tmp);
      if (str_arg->null_value)
        return CMP_DATE_DFLT;
      value= get_date_from_str(thd, str_val, t_type, date_arg->name, &error);
      if (error)
        return CMP_DATE_DFLT;
      if (const_value)
        *const_value= value;
    }
  }
  return cmp_type;
}


int Arg_comparator::set_cmp_func(Item_bool_func2 *owner_arg,
                                        Item **a1, Item **a2,
                                        Item_result type)
{
  enum enum_date_cmp_type cmp_type;
  ulonglong const_value;
  a= a1;
  b= a2;

  if ((cmp_type= can_compare_as_dates(*a, *b, &const_value)))
  {
    thd= current_thd;
    owner= owner_arg;
    a_type= (*a)->field_type();
    b_type= (*b)->field_type();
    a_cache= 0;
    b_cache= 0;

    if (cmp_type != CMP_DATE_WITH_DATE &&
        ((*b)->const_item() || (*a)->const_item()))
    {
      Item_cache_int *cache= new Item_cache_int();
      /* Mark the cache as non-const to prevent re-caching. */
      cache->set_used_tables(1);
      if (!(*a)->is_datetime())
      {
        cache->store((*a), const_value);
        a_cache= cache;
        a= (Item **)&a_cache;
      }
      else
      {
        cache->store((*b), const_value);
        b_cache= cache;
        b= (Item **)&b_cache;
      }
    }
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    is_nulls_eq= test(owner && owner->functype() == Item_func::EQUAL_FUNC);
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    func= &Arg_comparator::compare_datetime;
    return 0;
  }
  return set_compare_func(owner_arg, type);
}


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void Arg_comparator::set_datetime_cmp_func(Item **a1, Item **b1)
{
  thd= current_thd;
  /* A caller will handle null values by itself. */
  owner= NULL;
  a= a1;
  b= b1;
  a_type= (*a)->field_type();
  b_type= (*b)->field_type();
  a_cache= 0;
  b_cache= 0;
  is_nulls_eq= FALSE;
  func= &Arg_comparator::compare_datetime;
}

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/*
  Retrieves correct DATETIME value from given item.

  SYNOPSIS
    get_datetime_value()
    thd                 thread handle
    item_arg   [in/out] item to retrieve DATETIME value from
    cache_arg  [in/out] pointer to place to store the caching item to
    warn_item  [in]     item for issuing the conversion warning
    is_null    [out]    TRUE <=> the item_arg is null

  DESCRIPTION
    Retrieves the correct DATETIME value from given item for comparison by the
    compare_datetime() function.
    If item's result can be compared as longlong then its int value is used
    and its string value is used otherwise. Strings are always parsed and
    converted to int values by the get_date_from_str() function.
    This allows us to compare correctly string dates with missed insignificant
    zeros. If an item is a constant one then its value is cached and it isn't
    get parsed again. An Item_cache_int object is used for caching values. It
    seamlessly substitutes the original item.  The cache item is marked as
    non-constant to prevent re-caching it again.  In order to compare
    correctly DATE and DATETIME items the result of the former are treated as
    a DATETIME with zero time (00:00:00).

  RETURN
    obtained value
*/

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ulonglong
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get_datetime_value(THD *thd, Item ***item_arg, Item **cache_arg,
                   Item *warn_item, bool *is_null)
{
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  ulonglong value= 0;
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  String buf, *str= 0;
  Item *item= **item_arg;

  if (item->result_as_longlong())
  {
    value= item->val_int();
    *is_null= item->null_value;
    if (item->field_type() == MYSQL_TYPE_DATE)
      value*= 1000000L;
  }
  else
  {
    str= item->val_str(&buf);
    *is_null= item->null_value;
  }
  if (*is_null)
    return -1;
  /*
    Convert strings to the integer DATE/DATETIME representation.
    Even if both dates provided in strings we can't compare them directly as
    strings as there is no warranty that they are correct and do not miss
    some insignificant zeros.
  */
  if (str)
  {
    bool error;
    enum_field_types f_type= warn_item->field_type();
    timestamp_type t_type= f_type ==
      MYSQL_TYPE_DATE ? MYSQL_TIMESTAMP_DATE : MYSQL_TIMESTAMP_DATETIME;
    value= get_date_from_str(thd, str, t_type, warn_item->name, &error);
  }
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  if (item->const_item() && cache_arg)
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  {
    Item_cache_int *cache= new Item_cache_int();
    /* Mark the cache as non-const to prevent re-caching. */
    cache->set_used_tables(1);
    cache->store(item, value);
    *cache_arg= cache;
    *item_arg= cache_arg;
  }
  return value;
}

/*
  Compare items values as dates.

  SYNOPSIS
    Arg_comparator::compare_datetime()

  DESCRIPTION
    Compare items values as DATE/DATETIME for both EQUAL_FUNC and from other
    comparison functions. The correct DATETIME values are obtained
    with help of the get_datetime_value() function.

  RETURN
    If is_nulls_eq is TRUE:
       1    if items are equal or both are null
       0    otherwise
    If is_nulls_eq is FALSE:
      -1   a < b or one of items is null
       0   a == b
       1   a > b
*/

int Arg_comparator::compare_datetime()
{
  bool is_null= FALSE;
  ulonglong a_value, b_value;

  /* Get DATE/DATETIME value of the 'a' item. */
  a_value= get_datetime_value(thd, &a, &a_cache, *b, &is_null);
  if (!is_nulls_eq && is_null)
  {
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    if (owner)
      owner->null_value= 1;
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    return -1;
  }

  /* Get DATE/DATETIME value of the 'b' item. */
  b_value= get_datetime_value(thd, &b, &b_cache, *a, &is_null);
  if (is_null)
  {
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    if (owner)
      owner->null_value= is_nulls_eq ? 0 : 1;
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    return is_nulls_eq ? 1 : -1;
  }

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  if (owner)
    owner->null_value= 0;
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  /* Compare values. */
  if (is_nulls_eq)
    return (a_value == b_value);
  return a_value < b_value ? -1 : (a_value > b_value ? 1 : 0);
}


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int Arg_comparator::compare_string()
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{
  String *res1,*res2;
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  if ((res1= (*a)->val_str(&owner->tmp_value1)))
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  {
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    if ((res2= (*b)->val_str(&owner->tmp_value2)))
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    {
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      owner->null_value= 0;
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      return sortcmp(res1,res2,cmp_collation.collation);
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    }
  }
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  owner->null_value= 1;
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  return -1;
}

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/*
  Compare strings byte by byte. End spaces are also compared.

  RETURN
   < 0	*a < *b
   0	*b == *b
   > 0	*a > *b
*/

int Arg_comparator::compare_binary_string()
{
  String *res1,*res2;
  if ((res1= (*a)->val_str(&owner->tmp_value1)))
  {
    if ((res2= (*b)->val_str(&owner->tmp_value2)))
    {
      owner->null_value= 0;
      uint res1_length= res1->length();
      uint res2_length= res2->length();
      int cmp= memcmp(res1->ptr(), res2->ptr(), min(res1_length,res2_length));
      return cmp ? cmp : (int) (res1_length - res2_length);
    }
  }
  owner->null_value= 1;
  return -1;
}


/*
  Compare strings, but take into account that NULL == NULL
*/

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int Arg_comparator::compare_e_string()
{
  String *res1,*res2;
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  res1= (*a)->val_str(&owner->tmp_value1);
  res2= (*b)->val_str(&owner->tmp_value2);
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  if (!res1 || !res2)
    return test(res1 == res2);
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  return test(sortcmp(res1, res2, cmp_collation.collation) == 0);
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}


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int Arg_comparator::compare_e_binary_string()
{
  String *res1,*res2;
  res1= (*a)->val_str(&owner->tmp_value1);
  res2= (*b)->val_str(&owner->tmp_value2);
  if (!res1 || !res2)
    return test(res1 == res2);
  return test(stringcmp(res1, res2) == 0);
}


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int Arg_comparator::compare_real()
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{
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  /*
    Fix yet another manifestation of Bug#2338. 'Volatile' will instruct
    gcc to flush double values out of 80-bit Intel FPU registers before
    performing the comparison.
  */
  volatile double val1, val2;
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  val1= (*a)->val_real();
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  if (!(*a)->null_value)
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  {
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    val2= (*b)->val_real();
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    if (!(*b)->null_value)
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    {
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      owner->null_value= 0;
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      if (val1 < val2)	return -1;
      if (val1 == val2) return 0;
      return 1;
    }
  }
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  owner->null_value= 1;
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  return -1;
}

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int Arg_comparator::compare_decimal()
{
  my_decimal value1;
  my_decimal *val1= (*a)->val_decimal(&value1);
  if (!(*a)->null_value)
  {
    my_decimal value2;
    my_decimal *val2= (*b)->val_decimal(&value2);
    if (!(*b)->null_value)
    {
      owner->null_value= 0;
      return my_decimal_cmp(val1, val2);
    }
  }
  owner->null_value= 1;
  return -1;
}

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int Arg_comparator::compare_e_real()
{
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  double val1= (*a)->val_real();
  double val2= (*b)->val_real();
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  if ((*a)->null_value || (*b)->null_value)
    return test((*a)->null_value && (*b)->null_value);
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  return test(val1 == val2);
}
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int Arg_comparator::compare_e_decimal()
{
  my_decimal value1, value2;
  my_decimal *val1= (*a)->val_decimal(&value1);
  my_decimal *val2= (*b)->val_decimal(&value2);
  if ((*a)->null_value || (*b)->null_value)
    return test((*a)->null_value && (*b)->null_value);
  return test(my_decimal_cmp(val1, val2) == 0);
}

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int Arg_comparator::compare_real_fixed()
{
  /*
    Fix yet another manifestation of Bug#2338. 'Volatile' will instruct
    gcc to flush double values out of 80-bit Intel FPU registers before
    performing the comparison.
  */
  volatile double val1, val2;
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  val1= (*a)->val_real();
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  if (!(*a)->null_value)
  {
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    val2= (*b)->val_real();
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    if (!(*b)->null_value)
    {
      owner->null_value= 0;
      if (val1 == val2 || fabs(val1 - val2) < precision)
        return 0;
      if (val1 < val2)
        return -1;
      return 1;
    }
  }
  owner->null_value= 1;
  return -1;
}


int Arg_comparator::compare_e_real_fixed()
{
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  double val1= (*a)->val_real();
  double val2= (*b)->val_real();
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  if ((*a)->null_value || (*b)->null_value)
    return test((*a)->null_value && (*b)->null_value);
  return test(val1 == val2 || fabs(val1 - val2) < precision);
}


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int Arg_comparator::compare_int_signed()
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{
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  longlong val1= (*a)->val_int();
  if (!(*a)->null_value)
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  {
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    longlong val2= (*b)->val_int();
    if (!(*b)->null_value)
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    {
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      owner->null_value= 0;
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      if (val1 < val2)	return -1;
      if (val1 == val2)   return 0;
      return 1;
    }
  }
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  owner->null_value= 1;
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  return -1;
}

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/*
  Compare values as BIGINT UNSIGNED.
*/

int Arg_comparator::compare_int_unsigned()
{
  ulonglong val1= (*a)->val_int();
  if (!(*a)->null_value)
  {
    ulonglong val2= (*b)->val_int();
    if (!(*b)->null_value)
    {
      owner->null_value= 0;
      if (val1 < val2)	return -1;
      if (val1 == val2)   return 0;
      return 1;
    }
  }
  owner->null_value= 1;
  return -1;
}


/*
  Compare signed (*a) with unsigned (*B)
*/

int Arg_comparator::compare_int_signed_unsigned()
{
  longlong sval1= (*a)->val_int();
  if (!(*a)->null_value)
  {
    ulonglong uval2= (ulonglong)(*b)->val_int();
    if (!(*b)->null_value)
    {
      owner->null_value= 0;
      if (sval1 < 0 || (ulonglong)sval1 < uval2)
        return -1;
      if ((ulonglong)sval1 == uval2)
        return 0;
      return 1;
    }
  }
  owner->null_value= 1;
  return -1;
}


/*
  Compare unsigned (*a) with signed (*B)
*/

int Arg_comparator::compare_int_unsigned_signed()
{
  ulonglong uval1= (ulonglong)(*a)->val_int();
  if (!(*a)->null_value)
  {
    longlong sval2= (*b)->val_int();
    if (!(*b)->null_value)
    {
      owner->null_value= 0;
      if (sval2 < 0)
        return 1;
      if (uval1 < (ulonglong)sval2)
        return -1;
      if (uval1 == (ulonglong)sval2)
        return 0;
      return 1;
    }
  }
  owner->null_value= 1;
  return -1;
}


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int Arg_comparator::compare_e_int()
{
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  longlong val1= (*a)->val_int();
  longlong val2= (*b)->val_int();
  if ((*a)->null_value || (*b)->null_value)
    return test((*a)->null_value && (*b)->null_value);
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  return test(val1 == val2);
}

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/*
  Compare unsigned *a with signed *b or signed *a with unsigned *b.
*/
int Arg_comparator::compare_e_int_diff_signedness()
{
  longlong val1= (*a)->val_int();
  longlong val2= (*b)->val_int();
  if ((*a)->null_value || (*b)->null_value)
    return test((*a)->null_value && (*b)->null_value);
  return (val1 >= 0) && test(val1 == val2);
}
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int Arg_comparator::compare_row()
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{
  int res= 0;
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  bool was_null= 0;
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  (*a)->bring_value();
  (*b)->bring_value();
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  uint n= (*a)->cols();
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  for (uint i= 0; i<n; i++)
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  {
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    res= comparators[i].compare();
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    if (owner->null_value)
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    {
      // NULL was compared
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      switch (owner->functype()) {
      case Item_func::NE_FUNC:
        break; // NE never aborts on NULL even if abort_on_null is set
      case Item_func::LT_FUNC:
      case Item_func::LE_FUNC:
      case Item_func::GT_FUNC:
      case Item_func::GE_FUNC:
        return -1; // <, <=, > and >= always fail on NULL
      default: // EQ_FUNC
        if (owner->abort_on_null)
          return -1; // We do not need correct NULL returning
      }
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      was_null= 1;
      owner->null_value= 0;
      res= 0;  // continue comparison (maybe we will meet explicit difference)
    }
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    else if (res)
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      return res;
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  }
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  if (was_null)
  {
    /*
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      There was NULL(s) in comparison in some parts, but there was no
      explicit difference in other parts, so we have to return NULL.
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    */
    owner->null_value= 1;
    return -1;
  }
  return 0;
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}
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int Arg_comparator::compare_e_row()
{
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  (*a)->bring_value();
  (*b)->bring_value();
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  uint n= (*a)->cols();
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  for (uint i= 0; i<n; i++)
  {
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    if (!comparators[i].compare())
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      return 0;
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  }
  return 1;
}

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void Item_func_truth::fix_length_and_dec()
{
  maybe_null= 0;
  null_value= 0;
  decimals= 0;
  max_length= 1;
}


void Item_func_truth::print(String *str)
{
  str->append('(');
  args[0]->print(str);
  str->append(STRING_WITH_LEN(" is "));
  if (! affirmative)
    str->append(STRING_WITH_LEN("not "));
  if (value)
    str->append(STRING_WITH_LEN("true"));
  else
    str->append(STRING_WITH_LEN("false"));
  str->append(')');
}


bool Item_func_truth::val_bool()
{
  bool val= args[0]->val_bool();
  if (args[0]->null_value)
  {
    /*
      NULL val IS {TRUE, FALSE} --> FALSE
      NULL val IS NOT {TRUE, FALSE} --> TRUE
    */
    return (! affirmative);
  }

  if (affirmative)
  {
    /* {TRUE, FALSE} val IS {TRUE, FALSE} value */
    return (val == value);
  }

  /* {TRUE, FALSE} val IS NOT {TRUE, FALSE} value */
  return (val != value);
}


longlong Item_func_truth::val_int()
{
  return (val_bool() ? 1 : 0);
}


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bool Item_in_optimizer::fix_left(THD *thd, Item **ref)
1247
{
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  if (!args[0]->fixed && args[0]->fix_fields(thd, args) ||
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      !cache && !(cache= Item_cache::get_cache(args[0]->result_type())))
1250
    return 1;
1251

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  cache->setup(args[0]);
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  if (cache->cols() == 1)
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  {
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    if ((used_tables_cache= args[0]->used_tables()))
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      cache->set_used_tables(OUTER_REF_TABLE_BIT);
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    else
      cache->set_used_tables(0);
  }
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  else
  {
    uint n= cache->cols();
    for (uint i= 0; i < n; i++)
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    {
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      if (args[0]->element_index(i)->used_tables())
	((Item_cache *)cache->element_index(i))->set_used_tables(OUTER_REF_TABLE_BIT);
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      else
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	((Item_cache *)cache->element_index(i))->set_used_tables(0);
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    }
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    used_tables_cache= args[0]->used_tables();
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  }
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  not_null_tables_cache= args[0]->not_null_tables();
  with_sum_func= args[0]->with_sum_func;
  const_item_cache= args[0]->const_item();
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  return 0;
}


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bool Item_in_optimizer::fix_fields(THD *thd, Item **ref)
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{
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  DBUG_ASSERT(fixed == 0);
1282
  if (fix_left(thd, ref))
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    return TRUE;
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  if (args[0]->maybe_null)
    maybe_null=1;

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  if (!args[1]->fixed && args[1]->fix_fields(thd, args+1))
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    return TRUE;
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  Item_in_subselect * sub= (Item_in_subselect *)args[1];
  if (args[0]->cols() != sub->engine->cols())
  {
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    my_error(ER_OPERAND_COLUMNS, MYF(0), args[0]->cols());
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    return TRUE;
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  }
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  if (args[1]->maybe_null)
    maybe_null=1;
  with_sum_func= with_sum_func || args[1]->with_sum_func;
  used_tables_cache|= args[1]->used_tables();
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  not_null_tables_cache|= args[1]->not_null_tables();
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  const_item_cache&= args[1]->const_item();
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  fixed= 1;
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  return FALSE;
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}

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longlong Item_in_optimizer::val_int()
{
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  bool tmp;
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  DBUG_ASSERT(fixed == 1);
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  cache->store(args[0]);
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  if (cache->null_value)
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  {
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    if (((Item_in_subselect*)args[1])->is_top_level_item())
    {
      /*
        We're evaluating "NULL IN (SELECT ...)". The result can be NULL or
        FALSE, and we can return one instead of another. Just return NULL.
      */
      null_value= 1;
    }
    else
    {
      if (!((Item_in_subselect*)args[1])->is_correlated &&
          result_for_null_param != UNKNOWN)
      {
        /* Use cached value from previous execution */
        null_value= result_for_null_param;
      }
      else
      {
        /*
          We're evaluating "NULL IN (SELECT ...)". The result is:
             FALSE if SELECT produces an empty set, or
             NULL  otherwise.
          We disable the predicates we've pushed down into subselect, run the
          subselect and see if it has produced any rows.
        */
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        Item_in_subselect *item_subs=(Item_in_subselect*)args[1]; 
        if (cache->cols() == 1)
        {
          item_subs->set_cond_guard_var(0, FALSE);
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          (void) args[1]->val_bool_result();
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          result_for_null_param= null_value= !item_subs->engine->no_rows();
          item_subs->set_cond_guard_var(0, TRUE);
        }
        else
        {
          uint i;
          uint ncols= cache->cols();
          /*
            Turn off the predicates that are based on column compares for
            which the left part is currently NULL
          */
          for (i= 0; i < ncols; i++)
          {
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            if (cache->element_index(i)->null_value)
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              item_subs->set_cond_guard_var(i, FALSE);
          }
          
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          (void) args[1]->val_bool_result();
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          result_for_null_param= null_value= !item_subs->engine->no_rows();
          
          /* Turn all predicates back on */
          for (i= 0; i < ncols; i++)
            item_subs->set_cond_guard_var(i, TRUE);
        }
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      }
    }
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    return 0;
  }
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  tmp= args[1]->val_bool_result();
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  null_value= args[1]->null_value;
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  return tmp;
}

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void Item_in_optimizer::keep_top_level_cache()
{
  cache->keep_array();
  save_cache= 1;
}


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void Item_in_optimizer::cleanup()
{
  DBUG_ENTER("Item_in_optimizer::cleanup");
  Item_bool_func::cleanup();
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  if (!save_cache)
    cache= 0;
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  DBUG_VOID_RETURN;
}

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bool Item_in_optimizer::is_null()
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{
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  cache->store(args[0]);
  return (null_value= (cache->null_value || args[1]->is_null()));
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}
1400

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longlong Item_func_eq::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  int value= cmp.compare();
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  return value == 0 ? 1 : 0;
}

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/* Same as Item_func_eq, but NULL = NULL */

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void Item_func_equal::fix_length_and_dec()
{
  Item_bool_func2::fix_length_and_dec();
  maybe_null=null_value=0;
}

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longlong Item_func_equal::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  return cmp.compare();
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}

longlong Item_func_ne::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  int value= cmp.compare();
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  return value != 0 && !null_value ? 1 : 0;
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}


longlong Item_func_ge::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  int value= cmp.compare();
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  return value >= 0 ? 1 : 0;
}


longlong Item_func_gt::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  int value= cmp.compare();
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  return value > 0 ? 1 : 0;
}

longlong Item_func_le::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  int value= cmp.compare();
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  return value <= 0 && !null_value ? 1 : 0;
}


longlong Item_func_lt::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  int value= cmp.compare();
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  return value < 0 && !null_value ? 1 : 0;
}


longlong Item_func_strcmp::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  String *a=args[0]->val_str(&tmp_value1);
  String *b=args[1]->val_str(&tmp_value2);
  if (!a || !b)
  {
    null_value=1;
    return 0;
  }
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  int value= sortcmp(a,b,cmp.cmp_collation.collation);
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  null_value=0;
  return !value ? 0 : (value < 0 ? (longlong) -1 : (longlong) 1);
}


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bool Item_func_opt_neg::eq(const Item *item, bool binary_cmp) const
{
  /* Assume we don't have rtti */
  if (this == item)
    return 1;
  if (item->type() != FUNC_ITEM)
    return 0;
  Item_func *item_func=(Item_func*) item;
  if (arg_count != item_func->arg_count ||
      functype() != item_func->functype())
    return 0;
  if (negated != ((Item_func_opt_neg *) item_func)->negated)
    return 0;
  for (uint i=0; i < arg_count ; i++)
    if (!args[i]->eq(item_func->arguments()[i], binary_cmp))
      return 0;
  return 1;
}


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void Item_func_interval::fix_length_and_dec()
{
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  use_decimal_comparison= (row->element_index(0)->result_type() == DECIMAL_RESULT) ||
    (row->element_index(0)->result_type() == INT_RESULT);
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  if (row->cols() > 8)
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  {
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    bool consts=1;

    for (uint i=1 ; consts && i < row->cols() ; i++)
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    {
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      consts&= row->element_index(i)->const_item();
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    }
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    if (consts &&
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        (intervals=
          (interval_range*) sql_alloc(sizeof(interval_range)*(row->cols()-1))))
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    {
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      if (use_decimal_comparison)
      {
        for (uint i=1 ; i < row->cols(); i++)
        {
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          Item *el= row->element_index(i);
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          interval_range *range= intervals + (i-1);
          if ((el->result_type() == DECIMAL_RESULT) ||
              (el->result_type() == INT_RESULT))
          {
            range->type= DECIMAL_RESULT;
            range->dec.init();
            my_decimal *dec= el->val_decimal(&range->dec);
            if (dec != &range->dec)
            {
              range->dec= *dec;
              range->dec.fix_buffer_pointer();
            }
          }
          else
          {
            range->type= REAL_RESULT;
            range->dbl= el->val_real();
          }
        }
      }
      else
      {
        for (uint i=1 ; i < row->cols(); i++)
        {
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          intervals[i-1].dbl= row->element_index(i)->val_real();
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        }
      }
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    }
  }
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  maybe_null= 0;
  max_length= 2;
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  used_tables_cache|= row->used_tables();
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  not_null_tables_cache= row->not_null_tables();
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  with_sum_func= with_sum_func || row->with_sum_func;
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  const_item_cache&= row->const_item();
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}

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/*
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  Execute Item_func_interval()

  SYNOPSIS
    Item_func_interval::val_int()

  NOTES
    If we are doing a decimal comparison, we are
    evaluating the first item twice.

  RETURN
    -1 if null value,
    0 if lower than lowest
    1 - arg_count-1 if between args[n] and args[n+1]
    arg_count if higher than biggest argument
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*/

longlong Item_func_interval::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  double value;
1580
  my_decimal dec_buf, *dec= NULL;
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  uint i;

1583 1584
  if (use_decimal_comparison)
  {
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    dec= row->element_index(0)->val_decimal(&dec_buf);
    if (row->element_index(0)->null_value)
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      return -1;
    my_decimal2double(E_DEC_FATAL_ERROR, dec, &value);
  }
  else
  {
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    value= row->element_index(0)->val_real();
    if (row->element_index(0)->null_value)
1594
      return -1;
1595
  }
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  if (intervals)
  {					// Use binary search to find interval
    uint start,end;
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    start= 0;
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    end=   row->cols()-2;
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    while (start != end)
    {
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      uint mid= (start + end + 1) / 2;
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      interval_range *range= intervals + mid;
      my_bool cmp_result;
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      /*
        The values in the range intervall may have different types,
        Only do a decimal comparision of the first argument is a decimal
        and we are comparing against a decimal
      */
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      if (dec && range->type == DECIMAL_RESULT)
        cmp_result= my_decimal_cmp(&range->dec, dec) <= 0;
      else
        cmp_result= (range->dbl <= value);
      if (cmp_result)
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	start= mid;
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      else
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	end= mid - 1;
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    }
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    interval_range *range= intervals+start;
    return ((dec && range->type == DECIMAL_RESULT) ?
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            my_decimal_cmp(dec, &range->dec) < 0 :
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            value < range->dbl) ? 0 : start + 1;
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  }
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  for (i=1 ; i < row->cols() ; i++)
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  {
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    Item *el= row->element_index(i);
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    if (use_decimal_comparison &&
        ((el->result_type() == DECIMAL_RESULT) ||
         (el->result_type() == INT_RESULT)))
    {
1634
      my_decimal e_dec_buf, *e_dec= row->element_index(i)->val_decimal(&e_dec_buf);
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      if (my_decimal_cmp(e_dec, dec) > 0)
        return i-1;
    }
1638
    else if (row->element_index(i)->val_real() > value)
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      return i-1;
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  }
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  return i-1;
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}

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/*
  Perform context analysis of a BETWEEN item tree

  SYNOPSIS:
    fix_fields()
    thd     reference to the global context of the query thread
    tables  list of all open tables involved in the query
    ref     pointer to Item* variable where pointer to resulting "fixed"
            item is to be assigned

  DESCRIPTION
    This function performs context analysis (name resolution) and calculates
    various attributes of the item tree with Item_func_between as its root.
    The function saves in ref the pointer to the item or to a newly created
    item that is considered as a replacement for the original one.

  NOTES
    Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on
    a predicate/function level. Then it's easy to show that:
      T0(e BETWEEN e1 AND e2)     = union(T1(e),T1(e1),T1(e2))
      T1(e BETWEEN e1 AND e2)     = union(T1(e),intersection(T1(e1),T1(e2)))
      T0(e NOT BETWEEN e1 AND e2) = union(T1(e),intersection(T1(e1),T1(e2)))
      T1(e NOT BETWEEN e1 AND e2) = union(T1(e),intersection(T1(e1),T1(e2)))

  RETURN
    0   ok
    1   got error
*/

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bool Item_func_between::fix_fields(THD *thd, Item **ref)
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{
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  if (Item_func_opt_neg::fix_fields(thd, ref))
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    return 1;

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  thd->lex->current_select->between_count++;

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  /* not_null_tables_cache == union(T1(e),T1(e1),T1(e2)) */
  if (pred_level && !negated)
    return 0;

  /* not_null_tables_cache == union(T1(e), intersection(T1(e1),T1(e2))) */
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  not_null_tables_cache= (args[0]->not_null_tables() |
                          (args[1]->not_null_tables() &
                           args[2]->not_null_tables()));
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  return 0;
}


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void Item_func_between::fix_length_and_dec()
{
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  max_length= 1;
  THD *thd= current_thd;
  int i;
  bool datetime_found= FALSE;
  compare_as_dates= TRUE;
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  /*
    As some compare functions are generated after sql_yacc,
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    we have to check for out of memory conditions here
1705
  */
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  if (!args[0] || !args[1] || !args[2])
    return;
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  if ( agg_cmp_type(thd, &cmp_type, args, 3))
    return;
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  if (cmp_type == STRING_RESULT &&
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      agg_arg_charsets(cmp_collation, args, 3, MY_COLL_CMP_CONV, 1))
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   return;
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  /*
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    Detect the comparison of DATE/DATETIME items.
    At least one of items should be a DATE/DATETIME item and other items
    should return the STRING result.
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  */
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  for (i= 0; i < 3; i++)
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  {
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    if (args[i]->is_datetime())
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    {
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      datetime_found= TRUE;
      continue;
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    }
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    if (args[i]->result_type() == STRING_RESULT)
      continue;
    compare_as_dates= FALSE;
    break;
  }
  if (!datetime_found)
    compare_as_dates= FALSE;

  if (compare_as_dates)
  {
    ge_cmp.set_datetime_cmp_func(args, args + 1);
    le_cmp.set_datetime_cmp_func(args, args + 2);
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  }
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}


longlong Item_func_between::val_int()
{						// ANSI BETWEEN
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  DBUG_ASSERT(fixed == 1);
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  if (compare_as_dates)
  {
    int ge_res, le_res;

    ge_res= ge_cmp.compare();
    if ((null_value= args[0]->null_value))
      return 0;
    le_res= le_cmp.compare();

    if (!args[1]->null_value && !args[2]->null_value)
      return (longlong) ((ge_res >= 0 && le_res <=0) != negated);
    else if (args[1]->null_value)
    {
      null_value= le_res > 0;			// not null if false range.
    }
    else
    {
      null_value= ge_res < 0;
    }
  }
  else if (cmp_type == STRING_RESULT)
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  {
    String *value,*a,*b;
    value=args[0]->val_str(&value0);
    if ((null_value=args[0]->null_value))
      return 0;
    a=args[1]->val_str(&value1);
    b=args[2]->val_str(&value2);
    if (!args[1]->null_value && !args[2]->null_value)
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      return (longlong) ((sortcmp(value,a,cmp_collation.collation) >= 0 &&
                          sortcmp(value,b,cmp_collation.collation) <= 0) !=
                         negated);
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    if (args[1]->null_value && args[2]->null_value)
      null_value=1;
    else if (args[1]->null_value)
    {
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      // Set to not null if false range.
      null_value= sortcmp(value,b,cmp_collation.collation) <= 0;
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    }
    else
    {
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      // Set to not null if false range.
      null_value= sortcmp(value,a,cmp_collation.collation) >= 0;
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    }
  }
  else if (cmp_type == INT_RESULT)
  {
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    longlong value=args[0]->val_int(), a, b;
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    if ((null_value=args[0]->null_value))
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      return 0;					/* purecov: inspected */
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    a=args[1]->val_int();
    b=args[2]->val_int();
    if (!args[1]->null_value && !args[2]->null_value)
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      return (longlong) ((value >= a && value <= b) != negated);
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    if (args[1]->null_value && args[2]->null_value)
      null_value=1;
    else if (args[1]->null_value)
    {
      null_value= value <= b;			// not null if false range.
    }
    else
    {
      null_value= value >= a;
    }
  }
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  else if (cmp_type == DECIMAL_RESULT)
  {
    my_decimal dec_buf, *dec= args[0]->val_decimal(&dec_buf),
               a_buf, *a_dec, b_buf, *b_dec;
    if ((null_value=args[0]->null_value))
      return 0;					/* purecov: inspected */
    a_dec= args[1]->val_decimal(&a_buf);
    b_dec= args[2]->val_decimal(&b_buf);
    if (!args[1]->null_value && !args[2]->null_value)
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      return (longlong) ((my_decimal_cmp(dec, a_dec) >= 0 &&
                          my_decimal_cmp(dec, b_dec) <= 0) != negated);
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    if (args[1]->null_value && args[2]->null_value)
      null_value=1;
    else if (args[1]->null_value)
      null_value= (my_decimal_cmp(dec, b_dec) <= 0);
    else
      null_value= (my_decimal_cmp(dec, a_dec) >= 0);
  }
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  else
  {
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    double value= args[0]->val_real(),a,b;
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    if ((null_value=args[0]->null_value))
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      return 0;					/* purecov: inspected */
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    a= args[1]->val_real();
    b= args[2]->val_real();
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    if (!args[1]->null_value && !args[2]->null_value)
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      return (longlong) ((value >= a && value <= b) != negated);
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    if (args[1]->null_value && args[2]->null_value)
      null_value=1;
    else if (args[1]->null_value)
    {
      null_value= value <= b;			// not null if false range.
    }
    else
    {
      null_value= value >= a;
    }
  }
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  return (longlong) (!null_value && negated);
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}

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void Item_func_between::print(String *str)
{
  str->append('(');
  args[0]->print(str);
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  if (negated)
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    str->append(STRING_WITH_LEN(" not"));
  str->append(STRING_WITH_LEN(" between "));
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  args[1]->print(str);
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  str->append(STRING_WITH_LEN(" and "));
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  args[2]->print(str);
  str->append(')');
}

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void
Item_func_ifnull::fix_length_and_dec()
{
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  agg_result_type(&hybrid_type, args, 2);
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  maybe_null=args[1]->maybe_null;
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  decimals= max(args[0]->decimals, args[1]->decimals);
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  max_length= (hybrid_type == DECIMAL_RESULT || hybrid_type == INT_RESULT) ?
    (max(args[0]->max_length - args[0]->decimals,
         args[1]->max_length - args[1]->decimals) + decimals) :
    max(args[0]->max_length, args[1]->max_length);

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  switch (hybrid_type) {
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  case STRING_RESULT:
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    agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1);
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    break;
  case DECIMAL_RESULT:
  case REAL_RESULT:
    break;
  case INT_RESULT:
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    decimals= 0;
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    break;
  case ROW_RESULT:
  default:
    DBUG_ASSERT(0);
  }
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  cached_field_type= args[0]->field_type();
  if (cached_field_type != args[1]->field_type())
    cached_field_type= Item_func::field_type();
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}

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uint Item_func_ifnull::decimal_precision() const
{
  int max_int_part=max(args[0]->decimal_int_part(),args[1]->decimal_int_part());
  return min(max_int_part + decimals, DECIMAL_MAX_PRECISION);
}


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enum_field_types Item_func_ifnull::field_type() const 
{
  return cached_field_type;
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}

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Field *Item_func_ifnull::tmp_table_field(TABLE *table)
{
  return tmp_table_field_from_field_type(table);
}
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double
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Item_func_ifnull::real_op()
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{
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  DBUG_ASSERT(fixed == 1);
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  double value= args[0]->val_real();
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  if (!args[0]->null_value)
  {
    null_value=0;
    return value;
  }
1923
  value= args[1]->val_real();
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  if ((null_value=args[1]->null_value))
    return 0.0;
  return value;
}

longlong
1930
Item_func_ifnull::int_op()
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{
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  DBUG_ASSERT(fixed == 1);
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  longlong value=args[0]->val_int();
  if (!args[0]->null_value)
  {
    null_value=0;
    return value;
  }
  value=args[1]->val_int();
  if ((null_value=args[1]->null_value))
    return 0;
  return value;
}

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my_decimal *Item_func_ifnull::decimal_op(my_decimal *decimal_value)
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{
  DBUG_ASSERT(fixed == 1);
  my_decimal *value= args[0]->val_decimal(decimal_value);
  if (!args[0]->null_value)
  {
    null_value= 0;
    return value;
  }
  value= args[1]->val_decimal(decimal_value);
  if ((null_value= args[1]->null_value))
    return 0;
  return value;
}


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String *
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Item_func_ifnull::str_op(String *str)
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{
1965
  DBUG_ASSERT(fixed == 1);
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  String *res  =args[0]->val_str(str);
  if (!args[0]->null_value)
  {
    null_value=0;
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    res->set_charset(collation.collation);
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    return res;
  }
  res=args[1]->val_str(str);
  if ((null_value=args[1]->null_value))
    return 0;
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  res->set_charset(collation.collation);
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  return res;
}

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/*
  Perform context analysis of an IF item tree

  SYNOPSIS:
    fix_fields()
    thd     reference to the global context of the query thread
    tables  list of all open tables involved in the query
    ref     pointer to Item* variable where pointer to resulting "fixed"
            item is to be assigned

  DESCRIPTION
    This function performs context analysis (name resolution) and calculates
    various attributes of the item tree with Item_func_if as its root.
    The function saves in ref the pointer to the item or to a newly created
    item that is considered as a replacement for the original one.

  NOTES
    Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on
    a predicate/function level. Then it's easy to show that:
      T0(IF(e,e1,e2)  = T1(IF(e,e1,e2))
      T1(IF(e,e1,e2)) = intersection(T1(e1),T1(e2))

  RETURN
    0   ok
    1   got error
*/

bool
2009
Item_func_if::fix_fields(THD *thd, Item **ref)
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{
  DBUG_ASSERT(fixed == 0);
  args[0]->top_level_item();

2014
  if (Item_func::fix_fields(thd, ref))
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    return 1;

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  not_null_tables_cache= (args[1]->not_null_tables() &
                          args[2]->not_null_tables());
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  return 0;
}


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void
Item_func_if::fix_length_and_dec()
{
  maybe_null=args[1]->maybe_null || args[2]->maybe_null;
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  decimals= max(args[1]->decimals, args[2]->decimals);
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  unsigned_flag=args[1]->unsigned_flag && args[2]->unsigned_flag;
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  enum Item_result arg1_type=args[1]->result_type();
  enum Item_result arg2_type=args[2]->result_type();
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  bool null1=args[1]->const_item() && args[1]->null_value;
  bool null2=args[2]->const_item() && args[2]->null_value;
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  if (null1)
  {
    cached_result_type= arg2_type;
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    collation.set(args[2]->collation.collation);
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  }
  else if (null2)
  {
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    cached_result_type= arg1_type;
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    collation.set(args[1]->collation.collation);
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  }
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  else
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  {
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    agg_result_type(&cached_result_type, args+1, 2);
    if (cached_result_type == STRING_RESULT)
    {
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      if (agg_arg_charsets(collation, args+1, 2, MY_COLL_ALLOW_CONV, 1))
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        return;
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    }
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    else
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    {
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      collation.set(&my_charset_bin);	// Number
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    }
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  }
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  if ((cached_result_type == DECIMAL_RESULT )
      || (cached_result_type == INT_RESULT))
  {
    int len1= args[1]->max_length - args[1]->decimals
      - (args[1]->unsigned_flag ? 0 : 1);

    int len2= args[2]->max_length - args[2]->decimals
      - (args[2]->unsigned_flag ? 0 : 1);

    max_length=max(len1, len2) + decimals + (unsigned_flag ? 0 : 1);
  }
  else
    max_length= max(args[1]->max_length, args[2]->max_length);
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}


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uint Item_func_if::decimal_precision() const
{
  int precision=(max(args[1]->decimal_int_part(),args[2]->decimal_int_part())+
                 decimals);
  return min(precision, DECIMAL_MAX_PRECISION);
}


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double
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Item_func_if::val_real()
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{
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  DBUG_ASSERT(fixed == 1);
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  Item *arg= args[0]->val_bool() ? args[1] : args[2];
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  double value= arg->val_real();
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  null_value=arg->null_value;
  return value;
}

longlong
Item_func_if::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  Item *arg= args[0]->val_bool() ? args[1] : args[2];
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  longlong value=arg->val_int();
  null_value=arg->null_value;
  return value;
}

String *
Item_func_if::val_str(String *str)
{
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  DBUG_ASSERT(fixed == 1);
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  Item *arg= args[0]->val_bool() ? args[1] : args[2];
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  String *res=arg->val_str(str);
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  if (res)
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    res->set_charset(collation.collation);
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  null_value=arg->null_value;
  return res;
}


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my_decimal *
Item_func_if::val_decimal(my_decimal *decimal_value)
{
  DBUG_ASSERT(fixed == 1);
  Item *arg= args[0]->val_bool() ? args[1] : args[2];
  my_decimal *value= arg->val_decimal(decimal_value);
  null_value= arg->null_value;
  return value;
}


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void
Item_func_nullif::fix_length_and_dec()
{
  Item_bool_func2::fix_length_and_dec();
  maybe_null=1;
  if (args[0])					// Only false if EOM
  {
    max_length=args[0]->max_length;
    decimals=args[0]->decimals;
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    unsigned_flag= args[0]->unsigned_flag;
    cached_result_type= args[0]->result_type();
2139
    if (cached_result_type == STRING_RESULT &&
2140
        agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1))
2141
      return;
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  }
}

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/*
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  nullif () returns NULL if arguments are equal, else it returns the
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  first argument.
  Note that we have to evaluate the first argument twice as the compare
  may have been done with a different type than return value
*/

double
2154
Item_func_nullif::val_real()
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{
2156
  DBUG_ASSERT(fixed == 1);
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  double value;
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  if (!cmp.compare())
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  {
    null_value=1;
    return 0.0;
  }
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  value= args[0]->val_real();
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  null_value=args[0]->null_value;
  return value;
}

longlong
Item_func_nullif::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  longlong value;
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  if (!cmp.compare())
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  {
    null_value=1;
    return 0;
  }
  value=args[0]->val_int();
  null_value=args[0]->null_value;
  return value;
}

String *
Item_func_nullif::val_str(String *str)
{
2186
  DBUG_ASSERT(fixed == 1);
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  String *res;
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  if (!cmp.compare())
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  {
    null_value=1;
    return 0;
  }
  res=args[0]->val_str(str);
  null_value=args[0]->null_value;
  return res;
}

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my_decimal *
Item_func_nullif::val_decimal(my_decimal * decimal_value)
{
  DBUG_ASSERT(fixed == 1);
  my_decimal *res;
  if (!cmp.compare())
  {
    null_value=1;
    return 0;
  }
  res= args[0]->val_decimal(decimal_value);
  null_value= args[0]->null_value;
  return res;
}


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bool
Item_func_nullif::is_null()
{
2218
  return (null_value= (!cmp.compare() ? 1 : args[0]->null_value)); 
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}

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/*
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  CASE expression 
  Return the matching ITEM or NULL if all compares (including else) failed
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*/

Item *Item_func_case::find_item(String *str)
{
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  String *first_expr_str, *tmp;
  my_decimal *first_expr_dec, first_expr_dec_val;
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  longlong first_expr_int;
  double   first_expr_real;
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  char buff[MAX_FIELD_WIDTH];
  String buff_str(buff,sizeof(buff),default_charset());
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  /* These will be initialized later */
  LINT_INIT(first_expr_str);
  LINT_INIT(first_expr_int);
  LINT_INIT(first_expr_real);
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  LINT_INIT(first_expr_dec);
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  if (first_expr_num != -1)
  {
    switch (cmp_type)
    {
      case STRING_RESULT:
      	// We can't use 'str' here as this may be overwritten
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	if (!(first_expr_str= args[first_expr_num]->val_str(&buff_str)))
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	  return else_expr_num != -1 ? args[else_expr_num] : 0;	// Impossible
        break;
      case INT_RESULT:
	first_expr_int= args[first_expr_num]->val_int();
	if (args[first_expr_num]->null_value)
	  return else_expr_num != -1 ? args[else_expr_num] : 0;
	break;
      case REAL_RESULT:
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	first_expr_real= args[first_expr_num]->val_real();
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	if (args[first_expr_num]->null_value)
	  return else_expr_num != -1 ? args[else_expr_num] : 0;
	break;
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      case DECIMAL_RESULT:
        first_expr_dec= args[first_expr_num]->val_decimal(&first_expr_dec_val);
        if (args[first_expr_num]->null_value)
          return else_expr_num != -1 ? args[else_expr_num] : 0;
        break;
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      case ROW_RESULT:
      default:
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        // This case should never be chosen
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	DBUG_ASSERT(0);
	break;
    }
  }

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  // Compare every WHEN argument with it and return the first match
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  for (uint i=0 ; i < ncases ; i+=2)
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  {
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    if (first_expr_num == -1)
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    {
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      // No expression between CASE and the first WHEN
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      if (args[i]->val_bool())
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	return args[i+1];
      continue;
    }
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    switch (cmp_type) {
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    case STRING_RESULT:
      if ((tmp=args[i]->val_str(str)))		// If not null
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	if (sortcmp(tmp,first_expr_str,cmp_collation.collation)==0)
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	  return args[i+1];
      break;
    case INT_RESULT:
      if (args[i]->val_int()==first_expr_int && !args[i]->null_value) 
        return args[i+1];
      break;
    case REAL_RESULT: 
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      if (args[i]->val_real() == first_expr_real && !args[i]->null_value)
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        return args[i+1];
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      break;
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    case DECIMAL_RESULT:
    {
      my_decimal value;
      if (my_decimal_cmp(args[i]->val_decimal(&value), first_expr_dec) == 0)
        return args[i+1];
      break;
    }
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    case ROW_RESULT:
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    default:
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      // This case should never be chosen
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      DBUG_ASSERT(0);
      break;
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    }
  }
  // No, WHEN clauses all missed, return ELSE expression
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  return else_expr_num != -1 ? args[else_expr_num] : 0;
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}


String *Item_func_case::val_str(String *str)
{
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  DBUG_ASSERT(fixed == 1);
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  String *res;
  Item *item=find_item(str);

  if (!item)
  {
    null_value=1;
    return 0;
  }
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  null_value= 0;
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  if (!(res=item->val_str(str)))
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    null_value= 1;
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  return res;
}


longlong Item_func_case::val_int()
{
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  DBUG_ASSERT(fixed == 1);
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  char buff[MAX_FIELD_WIDTH];
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  String dummy_str(buff,sizeof(buff),default_charset());
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  Item *item=find_item(&dummy_str);
  longlong res;

  if (!item)
  {
    null_value=1;
    return 0;
  }
  res=item->val_int();
  null_value=item->null_value;
  return res;
}

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double Item_func_case::val_real()
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{
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  DBUG_ASSERT(fixed == 1);
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  char buff[MAX_FIELD_WIDTH];
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  String dummy_str(buff,sizeof(buff),default_charset());
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  Item *item=find_item(&dummy_str);
  double res;

  if (!item)
  {
    null_value=1;
    return 0;
  }
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  res= item->val_real();
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  null_value=item->null_value;
  return res;
}

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my_decimal *Item_func_case::val_decimal(my_decimal *decimal_value)
{
  DBUG_ASSERT(fixed == 1);
  char buff[MAX_FIELD_WIDTH];
  String dummy_str(buff, sizeof(buff), default_charset());
  Item *item= find_item(&dummy_str);
  my_decimal *res;

  if (!item)
  {
    null_value=1;
    return 0;
  }

  res= item->val_decimal(decimal_value);
  null_value= item->null_value;
  return res;
}


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bool Item_func_case::fix_fields(THD *thd, Item **ref)
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{
  /*
    buff should match stack usage from
    Item_func_case::val_int() -> Item_func_case::find_item()
  */
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#ifndef EMBEDDED_LIBRARY
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  char buff[MAX_FIELD_WIDTH*2+sizeof(String)*2+sizeof(String*)*2+sizeof(double)*2+sizeof(longlong)*2];
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#endif
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  bool res= Item_func::fix_fields(thd, ref);
  /*
    Call check_stack_overrun after fix_fields to be sure that stack variable
    is not optimized away
  */
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  if (check_stack_overrun(thd, STACK_MIN_SIZE, buff))
    return TRUE;				// Fatal error flag is set!
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  return res;
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}



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void Item_func_case::fix_length_and_dec()
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{
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  Item **agg;
  uint nagg;
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  THD *thd= current_thd;
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  if (!(agg= (Item**) sql_alloc(sizeof(Item*)*(ncases+1))))
    return;
  
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  /*
    Aggregate all THEN and ELSE expression types
    and collations when string result
  */
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  for (nagg= 0 ; nagg < ncases/2 ; nagg++)
    agg[nagg]= args[nagg*2+1];
  
  if (else_expr_num != -1)
    agg[nagg++]= args[else_expr_num];
  
  agg_result_type(&cached_result_type, agg, nagg);
  if ((cached_result_type == STRING_RESULT) &&
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      agg_arg_charsets(collation, agg, nagg, MY_COLL_ALLOW_CONV, 1))
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    return;
  
  
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  /*
    Aggregate first expression and all THEN expression types
    and collations when string comparison
  */
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  if (first_expr_num != -1)
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  {
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    agg[0]= args[first_expr_num];
    for (nagg= 0; nagg < ncases/2 ; nagg++)
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      agg[nagg+1]= args[nagg*2];
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    nagg++;
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    if (agg_cmp_type(thd, &cmp_type, agg, nagg))
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      return;
2450
    if ((cmp_type == STRING_RESULT) &&
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        agg_arg_charsets(cmp_collation, agg, nagg, MY_COLL_CMP_CONV, 1))
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      return;
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  }
2454
  
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  if (else_expr_num == -1 || args[else_expr_num]->maybe_null)
2456
    maybe_null=1;
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  max_length=0;
  decimals=0;
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  for (uint i=0 ; i < ncases ; i+=2)
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  {
    set_if_bigger(max_length,args[i+1]->max_length);
    set_if_bigger(decimals,args[i+1]->decimals);
  }
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  if (else_expr_num != -1) 
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  {
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    set_if_bigger(max_length,args[else_expr_num]->max_length);
    set_if_bigger(decimals,args[else_expr_num]->decimals);
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  }
}

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uint Item_func_case::decimal_precision() const
{
  int max_int_part=0;
  for (uint i=0 ; i < ncases ; i+=2)
    set_if_bigger(max_int_part, args[i+1]->decimal_int_part());

  if (else_expr_num != -1) 
    set_if_bigger(max_int_part, args[else_expr_num]->decimal_int_part());
  return min(max_int_part + decimals, DECIMAL_MAX_PRECISION);
}


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/* TODO:  Fix this so that it prints the whole CASE expression */
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void Item_func_case::print(String *str)
{
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  str->append(STRING_WITH_LEN("(case "));
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  if (first_expr_num != -1)
  {
    args[first_expr_num]->print(str);
    str->append(' ');
  }
  for (uint i=0 ; i < ncases ; i+=2)
  {
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    str->append(STRING_WITH_LEN("when "));
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    args[i]->print(str);
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    str->append(STRING_WITH_LEN(" then "));
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    args[i+1]->print(str);
    str->append(' ');
  }
  if (else_expr_num != -1)
  {
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    str->append(STRING_WITH_LEN("else "));
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    args[else_expr_num]->print(str);
    str->append(' ');
  }
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  str->append(STRING_WITH_LEN("end)"));
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}

/*
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  Coalesce - return first not NULL argument.
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*/

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String *Item_func_coalesce::str_op(String *str)
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{
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  DBUG_ASSERT(fixed == 1);
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  null_value=0;
  for (uint i=0 ; i < arg_count ; i++)
  {
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    String *res;
    if ((res=args[i]->val_str(str)))
      return res;
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  }
  null_value=1;
  return 0;
}

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longlong Item_func_coalesce::int_op()
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{
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  DBUG_ASSERT(fixed == 1);
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  null_value=0;
  for (uint i=0 ; i < arg_count ; i++)
  {
    longlong res=args[i]->val_int();
    if (!args[i]->null_value)
      return res;
  }
  null_value=1;
  return 0;
}

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double Item_func_coalesce::real_op()
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{
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  DBUG_ASSERT(fixed == 1);
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  null_value=0;
  for (uint i=0 ; i < arg_count ; i++)
  {
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    double res= args[i]->val_real();
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    if (!args[i]->null_value)
      return res;
  }
  null_value=1;
  return 0;
}


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my_decimal *Item_func_coalesce::decimal_op(my_decimal *decimal_value)
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{
  DBUG_ASSERT(fixed == 1);
  null_value= 0;
  for (uint i= 0; i < arg_count; i++)
  {
    my_decimal *res= args[i]->val_decimal(decimal_value);
    if (!args[i]->null_value)
      return res;
  }
  null_value=1;
  return 0;
}


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void Item_func_coalesce::fix_length_and_dec()
{
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  agg_result_type(&hybrid_type, args, arg_count);
  switch (hybrid_type) {
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  case STRING_RESULT:
    count_only_length();
    decimals= NOT_FIXED_DEC;
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    agg_arg_charsets(collation, args, arg_count, MY_COLL_ALLOW_CONV, 1);
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    break;
  case DECIMAL_RESULT:
    count_decimal_length();
    break;
  case REAL_RESULT:
    count_real_length();
    break;
  case INT_RESULT:
    count_only_length();
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    decimals= 0;
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    break;
  case ROW_RESULT:
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  default:
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    DBUG_ASSERT(0);
  }
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}

/****************************************************************************
2600
 Classes and function for the IN operator
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****************************************************************************/

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/*
  Determine which of the signed longlong arguments is bigger

  SYNOPSIS
    cmp_longs()
      a_val     left argument
      b_val     right argument

  DESCRIPTION
    This function will compare two signed longlong arguments
    and will return -1, 0, or 1 if left argument is smaller than,
    equal to or greater than the right argument.

  RETURN VALUE
    -1          left argument is smaller than the right argument.
    0           left argument is equal to the right argument.
    1           left argument is greater than the right argument.
*/
static inline int cmp_longs (longlong a_val, longlong b_val)
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{
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  return a_val < b_val ? -1 : a_val == b_val ? 0 : 1;
}


/*
  Determine which of the unsigned longlong arguments is bigger

  SYNOPSIS
    cmp_ulongs()
      a_val     left argument
      b_val     right argument

  DESCRIPTION
    This function will compare two unsigned longlong arguments
    and will return -1, 0, or 1 if left argument is smaller than,
    equal to or greater than the right argument.

  RETURN VALUE
    -1          left argument is smaller than the right argument.
    0           left argument is equal to the right argument.
    1           left argument is greater than the right argument.
*/
static inline int cmp_ulongs (ulonglong a_val, ulonglong b_val)
{
  return a_val < b_val ? -1 : a_val == b_val ? 0 : 1;
}


/*
  Compare two integers in IN value list format (packed_longlong) 

  SYNOPSIS
    cmp_longlong()
      cmp_arg   an argument passed to the calling function (qsort2)
      a         left argument
      b         right argument

  DESCRIPTION
    This function will compare two integer arguments in the IN value list
    format and will return -1, 0, or 1 if left argument is smaller than,
    equal to or greater than the right argument.
    It's used in sorting the IN values list and finding an element in it.
    Depending on the signedness of the arguments cmp_longlong() will
    compare them as either signed (using cmp_longs()) or unsigned (using
    cmp_ulongs()).

  RETURN VALUE
    -1          left argument is smaller than the right argument.
    0           left argument is equal to the right argument.
    1           left argument is greater than the right argument.
*/
int cmp_longlong(void *cmp_arg, 
                 in_longlong::packed_longlong *a,
                 in_longlong::packed_longlong *b)
{
  if (a->unsigned_flag != b->unsigned_flag)
  { 
    /* 
      One of the args is unsigned and is too big to fit into the 
      positive signed range. Report no match.
    */  
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    if (a->unsigned_flag && ((ulonglong) a->val) > (ulonglong) LONGLONG_MAX ||
        b->unsigned_flag && ((ulonglong) b->val) > (ulonglong) LONGLONG_MAX)
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      return a->unsigned_flag ? 1 : -1;
    /*
      Although the signedness differs both args can fit into the signed 
      positive range. Make them signed and compare as usual.
    */  
    return cmp_longs (a->val, b->val);
  }
  if (a->unsigned_flag)
    return cmp_ulongs ((ulonglong) a->val, (ulonglong) b->val);
  else
    return cmp_longs (a->val, b->val);
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}

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static int cmp_double(void *cmp_arg, double *a,double *b)
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{
  return *a < *b ? -1 : *a == *b ? 0 : 1;
}

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static int cmp_row(void *cmp_arg, cmp_item_row *a, cmp_item_row *b)
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{
  return a->compare(b);
}

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static int cmp_decimal(void *cmp_arg, my_decimal *a, my_decimal *b)
{
  /*
    We need call of fixing buffer pointer, because fast sort just copy
    decimal buffers in memory and pointers left pointing on old buffer place
  */
  a->fix_buffer_pointer();
  b->fix_buffer_pointer();
  return my_decimal_cmp(a, b);
}


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int in_vector::find(Item *item)
{
  byte *result=get_value(item);
  if (!result || !used_count)
    return 0;				// Null value

  uint start,end;
  start=0; end=used_count-1;
  while (start != end)
  {
    uint mid=(start+end+1)/2;
    int res;
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    if ((res=(*compare)(collation, base+mid*size, result)) == 0)
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      return 1;
    if (res < 0)
      start=mid;
    else
      end=mid-1;
  }
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  return (int) ((*compare)(collation, base+start*size, result) == 0);
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}

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in_string::in_string(uint elements,qsort2_cmp cmp_func, CHARSET_INFO *cs)
  :in_vector(elements, sizeof(String), cmp_func, cs),
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   tmp(buff, sizeof(buff), &my_charset_bin)
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{}

in_string::~in_string()
{
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  if (base)
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  {
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    // base was allocated with help of sql_alloc => following is OK
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    for (uint i=0 ; i < count ; i++)
      ((String*) base)[i].free();
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  }
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}

void in_string::set(uint pos,Item *item)
{
  String *str=((String*) base)+pos;
  String *res=item->val_str(str);
  if (res && res != str)
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  {
    if (res->uses_buffer_owned_by(str))
      res->copy();
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    *str= *res;
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  }
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  if (!str->charset())
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  {
    CHARSET_INFO *cs;
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    if (!(cs= item->collation.collation))
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      cs= &my_charset_bin;		// Should never happen for STR items
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    str->set_charset(cs);
  }
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}

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byte *in_string::get_value(Item *item)
{
  return (byte*) item->val_str(&tmp);
}

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in_row::in_row(uint elements, Item * item)
{
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  base= (char*) new cmp_item_row[count= elements];
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  size= sizeof(cmp_item_row);
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  compare= (qsort2_cmp) cmp_row;
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  tmp.store_value(item);
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  /*
    We need to reset these as otherwise we will call sort() with
    uninitialized (even if not used) elements
  */
  used_count= elements;
  collation= 0;
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}

in_row::~in_row()
{
  if (base)
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    delete [] (cmp_item_row*) base;
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}

byte *in_row::get_value(Item *item)
{
  tmp.store_value(item);
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  if (item->is_null())
    return 0;
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  return (byte *)&tmp;
}

void in_row::set(uint pos, Item *item)
{
  DBUG_ENTER("in_row::set");
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  DBUG_PRINT("enter", ("pos: %u  item: 0x%lx", pos, (ulong) item));
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  ((cmp_item_row*) base)[pos].store_value_by_template(&tmp, item);
  DBUG_VOID_RETURN;
}
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in_longlong::in_longlong(uint elements)
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  :in_vector(elements,sizeof(packed_longlong),(qsort2_cmp) cmp_longlong, 0)
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{}

void in_longlong::set(uint pos,Item *item)
{
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  struct packed_longlong *buff= &((packed_longlong*) base)[pos];
  
  buff->val= item->val_int();
  buff->unsigned_flag= item->unsigned_flag;
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}

byte *in_longlong::get_value(Item *item)
{
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  tmp.val= item->val_int();
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  if (item->null_value)
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    return 0;
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  tmp.unsigned_flag= item->unsigned_flag;
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  return (byte*) &tmp;
}

in_double::in_double(uint elements)
2842
  :in_vector(elements,sizeof(double),(qsort2_cmp) cmp_double, 0)
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{}

void in_double::set(uint pos,Item *item)
{
2847
  ((double*) base)[pos]= item->val_real();
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}

byte *in_double::get_value(Item *item)
{
2852
  tmp= item->val_real();
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  if (item->null_value)
2854
    return 0;					/* purecov: inspected */
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  return (byte*) &tmp;
}

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in_decimal::in_decimal(uint elements)
  :in_vector(elements, sizeof(my_decimal),(qsort2_cmp) cmp_decimal, 0)
{}


void in_decimal::set(uint pos, Item *item)
{
  /* as far as 'item' is constant, we can store reference on my_decimal */
  my_decimal *dec= ((my_decimal *)base) + pos;
  dec->len= DECIMAL_BUFF_LENGTH;
  dec->fix_buffer_pointer();
  my_decimal *res= item->val_decimal(dec);
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  /* if item->val_decimal() is evaluated to NULL then res == 0 */ 
  if (!item->null_value && res != dec)
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    my_decimal2decimal(res, dec);
}


byte *in_decimal::get_value(Item *item)
{
  my_decimal *result= item->val_decimal(&val);
  if (item->null_value)
    return 0;
  return (byte *)result;
}


cmp_item* cmp_item::get_comparator(Item_result type,
                                   CHARSET_INFO *cs)
2888
{
2889
  switch (type) {
2890
  case STRING_RESULT:
2891
    return new cmp_item_sort_string(cs);
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  case INT_RESULT:
    return new cmp_item_int;
  case REAL_RESULT:
    return new cmp_item_real;
  case ROW_RESULT:
    return new cmp_item_row;
2898 2899
  case DECIMAL_RESULT:
    return new cmp_item_decimal;
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  default:
    DBUG_ASSERT(0);
    break;
2903 2904 2905 2906
  }
  return 0; // to satisfy compiler :)
}

2907

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cmp_item* cmp_item_sort_string::make_same()
{
2910
  return new cmp_item_sort_string_in_static(cmp_charset);
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}

cmp_item* cmp_item_int::make_same()
{
  return new cmp_item_int();
}

cmp_item* cmp_item_real::make_same()
{
  return new cmp_item_real();
}

cmp_item* cmp_item_row::make_same()
{
  return new cmp_item_row();
}

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cmp_item_row::~cmp_item_row()
{
  DBUG_ENTER("~cmp_item_row");
2932
  DBUG_PRINT("enter",("this: 0x%lx", (long) this));
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  if (comparators)
  {
    for (uint i= 0; i < n; i++)
    {
      if (comparators[i])
	delete comparators[i];
    }
  }
  DBUG_VOID_RETURN;
}


2945 2946
void cmp_item_row::store_value(Item *item)
{
2947
  DBUG_ENTER("cmp_item_row::store_value");
2948
  n= item->cols();
2949
  if (!comparators)
2950
    comparators= (cmp_item **) current_thd->calloc(sizeof(cmp_item *)*n);
2951
  if (comparators)
2952
  {
2953
    item->bring_value();
2954
    item->null_value= 0;
2955
    for (uint i=0; i < n; i++)
2956
    {
2957
      if (!comparators[i])
2958
        if (!(comparators[i]=
2959 2960
              cmp_item::get_comparator(item->element_index(i)->result_type(),
                                       item->element_index(i)->collation.collation)))
2961
	  break;					// new failed
2962 2963
      comparators[i]->store_value(item->element_index(i));
      item->null_value|= item->element_index(i)->null_value;
2964
    }
2965
  }
2966
  DBUG_VOID_RETURN;
2967 2968
}

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2970 2971 2972 2973 2974
void cmp_item_row::store_value_by_template(cmp_item *t, Item *item)
{
  cmp_item_row *tmpl= (cmp_item_row*) t;
  if (tmpl->n != item->cols())
  {
2975
    my_error(ER_OPERAND_COLUMNS, MYF(0), tmpl->n);
2976 2977 2978 2979 2980
    return;
  }
  n= tmpl->n;
  if ((comparators= (cmp_item **) sql_alloc(sizeof(cmp_item *)*n)))
  {
2981
    item->bring_value();
2982 2983
    item->null_value= 0;
    for (uint i=0; i < n; i++)
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    {
      if (!(comparators[i]= tmpl->comparators[i]->make_same()))
	break;					// new failed
      comparators[i]->store_value_by_template(tmpl->comparators[i],
2988 2989
					      item->element_index(i));
      item->null_value|= item->element_index(i)->null_value;
2990
    }
2991 2992 2993
  }
}

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int cmp_item_row::cmp(Item *arg)
{
2997 2998 2999
  arg->null_value= 0;
  if (arg->cols() != n)
  {
3000
    my_error(ER_OPERAND_COLUMNS, MYF(0), n);
3001 3002
    return 1;
  }
3003
  bool was_null= 0;
3004
  arg->bring_value();
3005
  for (uint i=0; i < n; i++)
3006
  {
3007
    if (comparators[i]->cmp(arg->element_index(i)))
3008
    {
3009
      if (!arg->element_index(i)->null_value)
3010 3011
	return 1;
      was_null= 1;
3012
    }
3013
  }
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3014
  return (arg->null_value= was_null);
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}

3017

3018 3019
int cmp_item_row::compare(cmp_item *c)
{
3020
  cmp_item_row *l_cmp= (cmp_item_row *) c;
3021
  for (uint i=0; i < n; i++)
3022 3023
  {
    int res;
3024
    if ((res= comparators[i]->compare(l_cmp->comparators[i])))
3025
      return res;
3026
  }
3027 3028
  return 0;
}
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void cmp_item_decimal::store_value(Item *item)
{
  my_decimal *val= item->val_decimal(&value);
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  /* val may be zero if item is nnull */
  if (val && val != &value)
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    my_decimal2decimal(val, &value);
}


int cmp_item_decimal::cmp(Item *arg)
{
  my_decimal tmp_buf, *tmp= arg->val_decimal(&tmp_buf);
  if (arg->null_value)
    return 1;
  return my_decimal_cmp(&value, tmp);
}


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int cmp_item_decimal::compare(cmp_item *arg)
3050
{
3051 3052
  cmp_item_decimal *l_cmp= (cmp_item_decimal*) arg;
  return my_decimal_cmp(&value, &l_cmp->value);
3053 3054 3055 3056 3057 3058 3059 3060 3061
}


cmp_item* cmp_item_decimal::make_same()
{
  return new cmp_item_decimal();
}


3062 3063 3064
bool Item_func_in::nulls_in_row()
{
  Item **arg,**arg_end;
3065
  for (arg= args+1, arg_end= args+arg_count; arg != arg_end ; arg++)
3066 3067 3068 3069 3070 3071 3072
  {
    if ((*arg)->null_inside())
      return 1;
  }
  return 0;
}

3073

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/*
  Perform context analysis of an IN item tree

  SYNOPSIS:
    fix_fields()
    thd     reference to the global context of the query thread
    tables  list of all open tables involved in the query
    ref     pointer to Item* variable where pointer to resulting "fixed"
            item is to be assigned

  DESCRIPTION
    This function performs context analysis (name resolution) and calculates
    various attributes of the item tree with Item_func_in as its root.
    The function saves in ref the pointer to the item or to a newly created
    item that is considered as a replacement for the original one.

  NOTES
    Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on
    a predicate/function level. Then it's easy to show that:
      T0(e IN(e1,...,en))     = union(T1(e),intersection(T1(ei)))
      T1(e IN(e1,...,en))     = union(T1(e),intersection(T1(ei)))
      T0(e NOT IN(e1,...,en)) = union(T1(e),union(T1(ei)))
      T1(e NOT IN(e1,...,en)) = union(T1(e),intersection(T1(ei)))

  RETURN
    0   ok
    1   got error
*/

bool
3104
Item_func_in::fix_fields(THD *thd, Item **ref)
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{
  Item **arg, **arg_end;

3108
  if (Item_func_opt_neg::fix_fields(thd, ref))
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    return 1;

  /* not_null_tables_cache == union(T1(e),union(T1(ei))) */
  if (pred_level && negated)
    return 0;

  /* not_null_tables_cache = union(T1(e),intersection(T1(ei))) */
  not_null_tables_cache= ~(table_map) 0;
  for (arg= args + 1, arg_end= args + arg_count; arg != arg_end; arg++)
    not_null_tables_cache&= (*arg)->not_null_tables();
  not_null_tables_cache|= (*args)->not_null_tables();
  return 0;
}


3124
static int srtcmp_in(CHARSET_INFO *cs, const String *x,const String *y)
3125
{
3126
  return cs->coll->strnncollsp(cs,
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                               (uchar *) x->ptr(),x->length(),
3128
                               (uchar *) y->ptr(),y->length(), 0);
3129 3130
}

3131

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void Item_func_in::fix_length_and_dec()
{
3134 3135
  Item **arg, **arg_end;
  uint const_itm= 1;
3136
  THD *thd= current_thd;
3137
  
3138 3139
  if (agg_cmp_type(thd, &cmp_type, args, arg_count))
    return;
3140

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  if (cmp_type == STRING_RESULT &&
3142
      agg_arg_charsets(cmp_collation, args, arg_count, MY_COLL_CMP_CONV, 1))
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    return;

3145
  for (arg=args+1, arg_end=args+arg_count; arg != arg_end ; arg++)
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  {
    if (!arg[0]->const_item())
    {
      const_itm= 0;
      break;
    }
  }
3153

3154 3155 3156 3157
  /*
    Row item with NULLs inside can return NULL or FALSE => 
    they can't be processed as static
  */
3158
  if (const_itm && !nulls_in_row())
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3159
  {
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    /*
      IN must compare INT/DATE/DATETIME/TIMESTAMP columns and constants
      as int values (the same way as equality does).
      So we must check here if the column on the left and all the constant 
      values on the right can be compared as integers and adjust the 
      comparison type accordingly.
    */  
    if (args[0]->real_item()->type() == FIELD_ITEM &&
        thd->lex->sql_command != SQLCOM_CREATE_VIEW &&
        thd->lex->sql_command != SQLCOM_SHOW_CREATE &&
        cmp_type != INT_RESULT)
    {
      Field *field= ((Item_field*) (args[0]->real_item()))->field;
      if (field->can_be_compared_as_longlong())
      {
        bool all_converted= TRUE;
        for (arg=args+1, arg_end=args+arg_count; arg != arg_end ; arg++)
        {
          if (!convert_constant_item (thd, field, &arg[0]))
            all_converted= FALSE;
        }
        if (all_converted)
          cmp_type= INT_RESULT;
      }
    }
3185
    switch (cmp_type) {
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3186
    case STRING_RESULT:
3187
      array=new in_string(arg_count-1,(qsort2_cmp) srtcmp_in, 
3188
			  cmp_collation.collation);
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      break;
    case INT_RESULT:
3191
      array= new in_longlong(arg_count-1);
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      break;
    case REAL_RESULT:
3194
      array= new in_double(arg_count-1);
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3195
      break;
3196
    case ROW_RESULT:
3197
      array= new in_row(arg_count-1, args[0]);
3198
      break;
3199 3200 3201
    case DECIMAL_RESULT:
      array= new in_decimal(arg_count - 1);
      break;
3202 3203 3204
    default:
      DBUG_ASSERT(0);
      return;
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    }
3206
    if (array && !(thd->is_fatal_error))		// If not EOM
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    {
3208
      uint j=0;
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      for (uint i=1 ; i < arg_count ; i++)
3210 3211 3212 3213
      {
	array->set(j,args[i]);
	if (!args[i]->null_value)			// Skip NULL values
	  j++;
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	else
	  have_null= 1;
3216 3217 3218
      }
      if ((array->used_count=j))
	array->sort();
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    }
  }
  else
  {
3223
    in_item= cmp_item::get_comparator(cmp_type, cmp_collation.collation);
3224
    if (cmp_type  == STRING_RESULT)
3225
      in_item->cmp_charset= cmp_collation.collation;
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  }
3227
  max_length= 1;
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}


void Item_func_in::print(String *str)
{
  str->append('(');
3234
  args[0]->print(str);
3235
  if (negated)
3236 3237
    str->append(STRING_WITH_LEN(" not"));
  str->append(STRING_WITH_LEN(" in ("));
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  print_args(str, 1);
3239
  str->append(STRING_WITH_LEN("))"));
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}


longlong Item_func_in::val_int()
{
3245
  DBUG_ASSERT(fixed == 1);
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  if (array)
  {
3248 3249
    int tmp=array->find(args[0]);
    null_value=args[0]->null_value || (!tmp && have_null);
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    return (longlong) (!null_value && tmp != negated);
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  }
3252 3253
  in_item->store_value(args[0]);
  if ((null_value=args[0]->null_value))
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3254
    return 0;
3255
  have_null= 0;
3256
  for (uint i=1 ; i < arg_count ; i++)
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  {
    if (!in_item->cmp(args[i]) && !args[i]->null_value)
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      return (longlong) (!negated);
3260
    have_null|= args[i]->null_value;
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3261
  }
3262
  null_value= have_null;
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3263
  return (longlong) (!null_value && negated);
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}


longlong Item_func_bit_or::val_int()
{
3269
  DBUG_ASSERT(fixed == 1);
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  ulonglong arg1= (ulonglong) args[0]->val_int();
  if (args[0]->null_value)
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  ulonglong arg2= (ulonglong) args[1]->val_int();
  if (args[1]->null_value)
  {
    null_value=1;
    return 0;
  }
  null_value=0;
  return (longlong) (arg1 | arg2);
}


longlong Item_func_bit_and::val_int()
{
3289
  DBUG_ASSERT(fixed == 1);
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  ulonglong arg1= (ulonglong) args[0]->val_int();
  if (args[0]->null_value)
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  ulonglong arg2= (ulonglong) args[1]->val_int();
  if (args[1]->null_value)
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  null_value=0;
  return (longlong) (arg1 & arg2);
}

3306
Item_cond::Item_cond(THD *thd, Item_cond *item)
3307
  :Item_bool_func(thd, item),
3308 3309
   abort_on_null(item->abort_on_null),
   and_tables_cache(item->and_tables_cache)
3310 3311
{
  /*
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    item->list will be copied by copy_andor_arguments() call
3313 3314 3315
  */
}

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3317 3318 3319
void Item_cond::copy_andor_arguments(THD *thd, Item_cond *item)
{
  List_iterator_fast<Item> li(item->list);
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  while (Item *it= li++)
3321 3322
    list.push_back(it->copy_andor_structure(thd));
}
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bool
3326
Item_cond::fix_fields(THD *thd, Item **ref)
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{
3328
  DBUG_ASSERT(fixed == 0);
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  List_iterator<Item> li(list);
  Item *item;
3331
#ifndef EMBEDDED_LIBRARY
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  char buff[sizeof(char*)];			// Max local vars in function
3333
#endif
3334
  not_null_tables_cache= used_tables_cache= 0;
3335
  const_item_cache= 1;
3336 3337 3338 3339 3340
  /*
    and_table_cache is the value that Item_cond_or() returns for
    not_null_tables()
  */
  and_tables_cache= ~(table_map) 0;
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3342
  if (check_stack_overrun(thd, STACK_MIN_SIZE, buff))
3343
    return TRUE;				// Fatal error flag is set!
3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358
  /*
    The following optimization reduces the depth of an AND-OR tree.
    E.g. a WHERE clause like
      F1 AND (F2 AND (F2 AND F4))
    is parsed into a tree with the same nested structure as defined
    by braces. This optimization will transform such tree into
      AND (F1, F2, F3, F4).
    Trees of OR items are flattened as well:
      ((F1 OR F2) OR (F3 OR F4))   =>   OR (F1, F2, F3, F4)
    Items for removed AND/OR levels will dangle until the death of the
    entire statement.
    The optimization is currently prepared statements and stored procedures
    friendly as it doesn't allocate any memory and its effects are durable
    (i.e. do not depend on PS/SP arguments).
  */
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  while ((item=li++))
  {
3361
    table_map tmp_table_map;
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    while (item->type() == Item::COND_ITEM &&
3363 3364
	   ((Item_cond*) item)->functype() == functype() &&
           !((Item_cond*) item)->list.is_empty())
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    {						// Identical function
      li.replace(((Item_cond*) item)->list);
      ((Item_cond*) item)->list.empty();
      item= *li.ref();				// new current item
    }
3370 3371
    if (abort_on_null)
      item->top_level_item();
3372 3373

    // item can be substituted in fix_fields
3374
    if ((!item->fixed &&
3375
	 item->fix_fields(thd, li.ref())) ||
3376
	(item= *li.ref())->check_cols(1))
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      return TRUE; /* purecov: inspected */
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    used_tables_cache|=     item->used_tables();
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    if (item->const_item())
      and_tables_cache= (table_map) 0;
    else
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    {
      tmp_table_map= item->not_null_tables();
      not_null_tables_cache|= tmp_table_map;
      and_tables_cache&= tmp_table_map;
      const_item_cache= FALSE;
    }  
3388
    with_sum_func=	    with_sum_func || item->with_sum_func;
3389
    with_subselect|=        item->with_subselect;
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    if (item->maybe_null)
      maybe_null=1;
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  }
3393
  thd->lex->current_select->cond_count+= list.elements;
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  fix_length_and_dec();
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  fixed= 1;
3396
  return FALSE;
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}

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bool Item_cond::walk(Item_processor processor, byte *arg)
{
  List_iterator_fast<Item> li(list);
  Item *item;
  while ((item= li++))
    if (item->walk(processor, arg))
      return 1;
  return Item_func::walk(processor, arg);
}

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/*
  Transform an Item_cond object with a transformer callback function
   
  SYNOPSIS
    transform()
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      transformer   the transformer callback function to be applied to the nodes
                    of the tree of the object
      arg           parameter to be passed to the transformer
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  DESCRIPTION
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    The function recursively applies the transform method to each
     member item of the condition list.
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    If the call of the method for a member item returns a new item
    the old item is substituted for a new one.
3424
    After this the transformer is applied to the root node
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    of the Item_cond object. 
     
  RETURN VALUES
    Item returned as the result of transformation of the root node 
*/

Item *Item_cond::transform(Item_transformer transformer, byte *arg)
3432
{
3433 3434
  DBUG_ASSERT(!current_thd->is_stmt_prepare());

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  List_iterator<Item> li(list);
  Item *item;
  while ((item= li++))
  {
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    Item *new_item= item->transform(transformer, arg);
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    if (!new_item)
      return 0;
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    /*
      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.
    */
3449
    if (new_item != item)
3450
      current_thd->change_item_tree(li.ref(), new_item);
3451
  }
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  return Item_func::transform(transformer, arg);
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}

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/*
  Compile Item_cond object with a processor and a transformer callback functions
   
  SYNOPSIS
    compile()
      analyzer      the analyzer callback function to be applied to the nodes
                    of the tree of the object
      arg_p         in/out parameter to be passed to the analyzer
      transformer   the transformer callback function to be applied to the nodes
                    of the tree of the object
      arg_t         parameter to be passed to the transformer
  
  DESCRIPTION
    First the function applies the analyzer to the root node of
    the Item_func object. Then if the analyzer succeeeds (returns TRUE)
    the function recursively applies the compile method to member
    item of the condition list.
    If the call of the method for a member item returns a new item
    the old item is substituted for a new one.
    After this the transformer is applied to the root node
    of the Item_cond object. 
     
  RETURN VALUES
    Item returned as the result of transformation of the root node 
*/

Item *Item_cond::compile(Item_analyzer analyzer, byte **arg_p,
                         Item_transformer transformer, byte *arg_t)
{
  if (!(this->*analyzer)(arg_p))
    return 0;
  
  List_iterator<Item> li(list);
  Item *item;
  while ((item= li++))
  {
    /* 
      The same parameter value of arg_p must be passed
      to analyze any argument of the condition formula.
    */   
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    byte *arg_v= *arg_p;
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    Item *new_item= item->compile(analyzer, &arg_v, transformer, arg_t);
    if (new_item && new_item != item)
      li.replace(new_item);
  }
  return Item_func::transform(transformer, arg_t);
}

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void Item_cond::traverse_cond(Cond_traverser traverser,
                              void *arg, traverse_order order)
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{
  List_iterator<Item> li(list);
  Item *item;

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  switch(order) {
  case(PREFIX):
    (*traverser)(this, arg);
    while ((item= li++))
    {
      item->traverse_cond(traverser, arg, order);
    }
3517
    (*traverser)(NULL, arg);
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    break;
  case(POSTFIX):
    while ((item= li++))
    {
      item->traverse_cond(traverser, arg, order);
    }
    (*traverser)(this, arg);
3525 3526
  }
}
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/*
  Move SUM items out from item tree and replace with reference

  SYNOPSIS
3532 3533 3534 3535
    split_sum_func()
    thd			Thread handler
    ref_pointer_array	Pointer to array of reference fields
    fields		All fields in select
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  NOTES
   This function is run on all expression (SELECT list, WHERE, HAVING etc)
   that have or refer (HAVING) to a SUM expression.

   The split is done to get an unique item for each SUM function
   so that we can easily find and calculate them.
   (Calculation done by update_sum_func() and copy_sum_funcs() in
   sql_select.cc)
*/

3547 3548
void Item_cond::split_sum_func(THD *thd, Item **ref_pointer_array,
                               List<Item> &fields)
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{
  List_iterator<Item> li(list);
  Item *item;
3552
  while ((item= li++))
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    item->split_sum_func2(thd, ref_pointer_array, fields, li.ref(), TRUE);
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}


table_map
Item_cond::used_tables() const
{						// This caches used_tables
  return used_tables_cache;
}

3563

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void Item_cond::update_used_tables()
{
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  List_iterator_fast<Item> li(list);
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  Item *item;
3568 3569 3570

  used_tables_cache=0;
  const_item_cache=1;
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  while ((item=li++))
  {
    item->update_used_tables();
3574
    used_tables_cache|= item->used_tables();
3575
    const_item_cache&= item->const_item();
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  }
}


void Item_cond::print(String *str)
{
  str->append('(');
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  List_iterator_fast<Item> li(list);
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  Item *item;
  if ((item=li++))
    item->print(str);
  while ((item=li++))
  {
    str->append(' ');
    str->append(func_name());
    str->append(' ');
    item->print(str);
  }
  str->append(')');
}

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3598
void Item_cond::neg_arguments(THD *thd)
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{
  List_iterator<Item> li(list);
  Item *item;
  while ((item= li++))		/* Apply not transformation to the arguments */
  {
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    Item *new_item= item->neg_transformer(thd);
    if (!new_item)
    {
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      if (!(new_item= new Item_func_not(item)))
	return;					// Fatal OEM error
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    }
    VOID(li.replace(new_item));
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  }
}


3615
/*
3616
  Evaluation of AND(expr, expr, expr ...)
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  NOTES:
    abort_if_null is set for AND expressions for which we don't care if the
    result is NULL or 0. This is set for:
    - WHERE clause
    - HAVING clause
    - IF(expression)

  RETURN VALUES
    1  If all expressions are true
    0  If all expressions are false or if we find a NULL expression and
       'abort_on_null' is set.
    NULL if all expression are either 1 or NULL
*/

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longlong Item_cond_and::val_int()
{
3635
  DBUG_ASSERT(fixed == 1);
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  List_iterator_fast<Item> li(list);
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  Item *item;
3638
  null_value= 0;
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  while ((item=li++))
  {
3641
    if (!item->val_bool())
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    {
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      if (abort_on_null || !(null_value= item->null_value))
	return 0;				// return FALSE
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    }
  }
3647
  return null_value ? 0 : 1;
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}

3650

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longlong Item_cond_or::val_int()
{
3653
  DBUG_ASSERT(fixed == 1);
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  List_iterator_fast<Item> li(list);
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  Item *item;
  null_value=0;
  while ((item=li++))
  {
3659
    if (item->val_bool())
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    {
      null_value=0;
      return 1;
    }
    if (item->null_value)
      null_value=1;
  }
  return 0;
}

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/*
  Create an AND expression from two expressions

  SYNOPSIS
   and_expressions()
   a		expression or NULL
   b    	expression.
   org_item	Don't modify a if a == *org_item
		If a == NULL, org_item is set to point at b,
		to ensure that future calls will not modify b.

  NOTES
    This will not modify item pointed to by org_item or b
    The idea is that one can call this in a loop and create and
    'and' over all items without modifying any of the original items.

  RETURN
    NULL	Error
    Item
*/

Item *and_expressions(Item *a, Item *b, Item **org_item)
{
  if (!a)
3694
    return (*org_item= (Item*) b);
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  if (a == *org_item)
  {
    Item_cond *res;
3698
    if ((res= new Item_cond_and(a, (Item*) b)))
3699
    {
3700
      res->used_tables_cache= a->used_tables() | b->used_tables();
3701 3702
      res->not_null_tables_cache= a->not_null_tables() | b->not_null_tables();
    }
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    return res;
  }
3705
  if (((Item_cond_and*) a)->add((Item*) b))
3706 3707
    return 0;
  ((Item_cond_and*) a)->used_tables_cache|= b->used_tables();
3708
  ((Item_cond_and*) a)->not_null_tables_cache|= b->not_null_tables();
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  return a;
}


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longlong Item_func_isnull::val_int()
{
3715
  DBUG_ASSERT(fixed == 1);
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  /*
    Handle optimization if the argument can't be null
    This has to be here because of the test in update_used_tables().
  */
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  if (!used_tables_cache && !with_subselect)
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    return cached_value;
3722
  return args[0]->is_null() ? 1: 0;
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}

3725 3726
longlong Item_is_not_null_test::val_int()
{
3727
  DBUG_ASSERT(fixed == 1);
3728
  DBUG_ENTER("Item_is_not_null_test::val_int");
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3729
  if (!used_tables_cache && !with_subselect)
3730 3731
  {
    owner->was_null|= (!cached_value);
3732
    DBUG_PRINT("info", ("cached :%ld", (long) cached_value));
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    DBUG_RETURN(cached_value);
  }
  if (args[0]->is_null())
  {
    DBUG_PRINT("info", ("null"))
    owner->was_null|= 1;
    DBUG_RETURN(0);
  }
  else
    DBUG_RETURN(1);
}

/* Optimize case of not_null_column IS NULL */
void Item_is_not_null_test::update_used_tables()
{
  if (!args[0]->maybe_null)
  {
    used_tables_cache= 0;			/* is always true */
    cached_value= (longlong) 1;
  }
  else
  {
    args[0]->update_used_tables();
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    if (!(used_tables_cache=args[0]->used_tables()) && !with_subselect)
3757 3758 3759 3760 3761 3762
    {
      /* Remember if the value is always NULL or never NULL */
      cached_value= (longlong) !args[0]->is_null();
    }
  }
}
3763

3764

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longlong Item_func_isnotnull::val_int()
{
3767
  DBUG_ASSERT(fixed == 1);
3768
  return args[0]->is_null() ? 0 : 1;
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}


3772 3773 3774 3775
void Item_func_isnotnull::print(String *str)
{
  str->append('(');
  args[0]->print(str);
3776
  str->append(STRING_WITH_LEN(" is not null)"));
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}


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longlong Item_func_like::val_int()
{
3782
  DBUG_ASSERT(fixed == 1);
3783
  String* res = args[0]->val_str(&tmp_value1);
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  if (args[0]->null_value)
  {
    null_value=1;
    return 0;
  }
3789
  String* res2 = args[1]->val_str(&tmp_value2);
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  if (args[1]->null_value)
  {
    null_value=1;
    return 0;
  }
  null_value=0;
3796 3797
  if (canDoTurboBM)
    return turboBM_matches(res->ptr(), res->length()) ? 1 : 0;
3798
  return my_wildcmp(cmp.cmp_collation.collation,
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		    res->ptr(),res->ptr()+res->length(),
		    res2->ptr(),res2->ptr()+res2->length(),
		    escape,wild_one,wild_many) ? 0 : 1;
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}


/* We can optimize a where if first character isn't a wildcard */

Item_func::optimize_type Item_func_like::select_optimize() const
{
3809
  if (args[1]->const_item())
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3810
  {
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    String* res2= args[1]->val_str((String *)&tmp_value2);

    if (!res2)
      return OPTIMIZE_NONE;

    if (*res2->ptr() != wild_many)
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    {
3818
      if (args[0]->result_type() != STRING_RESULT || *res2->ptr() != wild_one)
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	return OPTIMIZE_OP;
    }
  }
  return OPTIMIZE_NONE;
}

3825

3826
bool Item_func_like::fix_fields(THD *thd, Item **ref)
3827
{
3828
  DBUG_ASSERT(fixed == 0);
3829 3830
  if (Item_bool_func2::fix_fields(thd, ref) ||
      escape_item->fix_fields(thd, &escape_item))
3831
    return TRUE;
3832

3833
  if (!escape_item->const_during_execution())
3834
  {
3835
    my_error(ER_WRONG_ARGUMENTS,MYF(0),"ESCAPE");
3836
    return TRUE;
3837 3838 3839 3840 3841 3842
  }
  
  if (escape_item->const_item())
  {
    /* If we are on execution stage */
    String *escape_str= escape_item->val_str(&tmp_value1);
3843 3844
    if (escape_str)
    {
3845 3846 3847 3848 3849 3850 3851 3852 3853
      if (escape_used_in_parsing && (
             (((thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES) &&
                escape_str->numchars() != 1) ||
               escape_str->numchars() > 1)))
      {
        my_error(ER_WRONG_ARGUMENTS,MYF(0),"ESCAPE");
        return TRUE;
      }

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      if (use_mb(cmp.cmp_collation.collation))
3855
      {
3856
        CHARSET_INFO *cs= escape_str->charset();
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        my_wc_t wc;
        int rc= cs->cset->mb_wc(cs, &wc,
                                (const uchar*) escape_str->ptr(),
                                (const uchar*) escape_str->ptr() +
                                               escape_str->length());
        escape= (int) (rc > 0 ? wc : '\\');
      }
      else
      {
3866 3867 3868 3869 3870
        /*
          In the case of 8bit character set, we pass native
          code instead of Unicode code as "escape" argument.
          Convert to "cs" if charset of escape differs.
        */
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        CHARSET_INFO *cs= cmp.cmp_collation.collation;
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        uint32 unused;
        if (escape_str->needs_conversion(escape_str->length(),
                                         escape_str->charset(), cs, &unused))
        {
          char ch;
          uint errors;
          uint32 cnvlen= copy_and_convert(&ch, 1, cs, escape_str->ptr(),
                                          escape_str->length(),
                                          escape_str->charset(), &errors);
          escape= cnvlen ? ch : '\\';
        }
        else
          escape= *(escape_str->ptr());
3885 3886 3887 3888
      }
    }
    else
      escape= '\\';
3889

3890
    /*
3891 3892
      We could also do boyer-more for non-const items, but as we would have to
      recompute the tables for each row it's not worth it.
3893
    */
3894 3895
    if (args[1]->const_item() && !use_strnxfrm(collation.collation) &&
       !(specialflag & SPECIAL_NO_NEW_FUNC))
3896
    {
3897 3898
      String* res2 = args[1]->val_str(&tmp_value2);
      if (!res2)
3899
        return FALSE;				// Null argument
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      const size_t len   = res2->length();
      const char*  first = res2->ptr();
      const char*  last  = first + len - 1;
      /*
        len must be > 2 ('%pattern%')
        heuristic: only do TurboBM for pattern_len > 2
      */
      
      if (len > MIN_TURBOBM_PATTERN_LEN + 2 &&
          *first == wild_many &&
          *last  == wild_many)
      {
        const char* tmp = first + 1;
        for (; *tmp != wild_many && *tmp != wild_one && *tmp != escape; tmp++) ;
        canDoTurboBM = (tmp == last) && !use_mb(args[0]->collation.collation);
      }
      if (canDoTurboBM)
      {
        pattern     = first + 1;
3920
        pattern_len = (int) len - 2;
3921
        DBUG_PRINT("info", ("Initializing pattern: '%s'", first));
3922 3923 3924
        int *suff = (int*) thd->alloc((int) (sizeof(int)*
                                      ((pattern_len + 1)*2+
                                      alphabet_size)));
3925 3926 3927 3928 3929 3930
        bmGs      = suff + pattern_len + 1;
        bmBc      = bmGs + pattern_len + 1;
        turboBM_compute_good_suffix_shifts(suff);
        turboBM_compute_bad_character_shifts();
        DBUG_PRINT("info",("done"));
      }
3931 3932
    }
  }
3933
  return FALSE;
3934 3935
}

3936 3937 3938 3939 3940 3941
void Item_func_like::cleanup()
{
  canDoTurboBM= FALSE;
  Item_bool_func2::cleanup();
}

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#ifdef USE_REGEX

bool
3945
Item_func_regex::fix_fields(THD *thd, Item **ref)
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{
3947
  DBUG_ASSERT(fixed == 0);
3948
  if ((!args[0]->fixed &&
3949
       args[0]->fix_fields(thd, args)) || args[0]->check_cols(1) ||
3950
      (!args[1]->fixed &&
3951
       args[1]->fix_fields(thd, args + 1)) || args[1]->check_cols(1))
3952
    return TRUE;				/* purecov: inspected */
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3953
  with_sum_func=args[0]->with_sum_func || args[1]->with_sum_func;
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  max_length= 1;
  decimals= 0;
3956

3957
  if (agg_arg_charsets(cmp_collation, args, 2, MY_COLL_CMP_CONV, 1))
3958
    return TRUE;
3959

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  used_tables_cache=args[0]->used_tables() | args[1]->used_tables();
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  not_null_tables_cache= (args[0]->not_null_tables() |
			  args[1]->not_null_tables());
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  const_item_cache=args[0]->const_item() && args[1]->const_item();
  if (!regex_compiled && args[1]->const_item())
  {
    char buff[MAX_FIELD_WIDTH];
3967
    String tmp(buff,sizeof(buff),&my_charset_bin);
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    String *res=args[1]->val_str(&tmp);
    if (args[1]->null_value)
    {						// Will always return NULL
      maybe_null=1;
3972
      return FALSE;
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    }
    int error;
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    if ((error= my_regcomp(&preg,res->c_ptr(),
                           ((cmp_collation.collation->state &
                             (MY_CS_BINSORT | MY_CS_CSSORT)) ?
                            REG_EXTENDED | REG_NOSUB :
                            REG_EXTENDED | REG_NOSUB | REG_ICASE),
                           cmp_collation.collation)))
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    {
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      (void) my_regerror(error,&preg,buff,sizeof(buff));
3983
      my_error(ER_REGEXP_ERROR, MYF(0), buff);
3984
      return TRUE;
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    }
    regex_compiled=regex_is_const=1;
    maybe_null=args[0]->maybe_null;
  }
  else
    maybe_null=1;
3991
  fixed= 1;
3992
  return FALSE;
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}

3995

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longlong Item_func_regex::val_int()
{
3998
  DBUG_ASSERT(fixed == 1);
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  char buff[MAX_FIELD_WIDTH];
4000
  String *res, tmp(buff,sizeof(buff),&my_charset_bin);
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  res=args[0]->val_str(&tmp);
  if (args[0]->null_value)
  {
    null_value=1;
    return 0;
  }
  if (!regex_is_const)
  {
    char buff2[MAX_FIELD_WIDTH];
4011
    String *res2, tmp2(buff2,sizeof(buff2),&my_charset_bin);
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    res2= args[1]->val_str(&tmp2);
    if (args[1]->null_value)
    {
      null_value=1;
      return 0;
    }
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    if (!regex_compiled || stringcmp(res2,&prev_regexp))
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    {
      prev_regexp.copy(*res2);
      if (regex_compiled)
      {
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4024
	my_regfree(&preg);
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	regex_compiled=0;
      }
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Merge  
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      if (my_regcomp(&preg,res2->c_ptr_safe(),
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                     ((cmp_collation.collation->state &
                       (MY_CS_BINSORT | MY_CS_CSSORT)) ?
                      REG_EXTENDED | REG_NOSUB :
                      REG_EXTENDED | REG_NOSUB | REG_ICASE),
                     cmp_collation.collation))
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      {
	null_value=1;
	return 0;
      }
      regex_compiled=1;
    }
  }
  null_value=0;
4041
  return my_regexec(&preg,res->c_ptr_safe(),0,(my_regmatch_t*) 0,0) ? 0 : 1;
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}


4045
void Item_func_regex::cleanup()
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{
4047 4048
  DBUG_ENTER("Item_func_regex::cleanup");
  Item_bool_func::cleanup();
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  if (regex_compiled)
  {
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4051
    my_regfree(&preg);
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    regex_compiled=0;
  }
4054
  DBUG_VOID_RETURN;
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}

4057

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4058
#endif /* USE_REGEX */
4059 4060 4061


#ifdef LIKE_CMP_TOUPPER
4062
#define likeconv(cs,A) (uchar) (cs)->toupper(A)
4063
#else
4064
#define likeconv(cs,A) (uchar) (cs)->sort_order[(uchar) (A)]
4065 4066 4067 4068 4069 4070 4071 4072
#endif


/**********************************************************************
  turboBM_compute_suffixes()
  Precomputation dependent only on pattern_len.
**********************************************************************/

4073
void Item_func_like::turboBM_compute_suffixes(int *suff)
4074 4075 4076 4077
{
  const int   plm1 = pattern_len - 1;
  int            f = 0;
  int            g = plm1;
4078
  int *const splm1 = suff + plm1;
4079
  CHARSET_INFO	*cs= cmp.cmp_collation.collation;
4080 4081 4082

  *splm1 = pattern_len;

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  if (!cs->sort_order)
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  {
    int i;
    for (i = pattern_len - 2; i >= 0; i--)
    {
      int tmp = *(splm1 + i - f);
      if (g < i && tmp < i - g)
	suff[i] = tmp;
      else
      {
	if (i < g)
	  g = i; // g = min(i, g)
	f = i;
	while (g >= 0 && pattern[g] == pattern[g + plm1 - f])
	  g--;
	suff[i] = f - g;
      }
    }
  }
  else
  {
    int i;
    for (i = pattern_len - 2; 0 <= i; --i)
    {
      int tmp = *(splm1 + i - f);
      if (g < i && tmp < i - g)
	suff[i] = tmp;
      else
      {
	if (i < g)
	  g = i; // g = min(i, g)
	f = i;
4115
	while (g >= 0 &&
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	       likeconv(cs, pattern[g]) == likeconv(cs, pattern[g + plm1 - f]))
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	  g--;
	suff[i] = f - g;
      }
    }
  }
}


/**********************************************************************
   turboBM_compute_good_suffix_shifts()
   Precomputation dependent only on pattern_len.
**********************************************************************/

4130
void Item_func_like::turboBM_compute_good_suffix_shifts(int *suff)
4131 4132 4133
{
  turboBM_compute_suffixes(suff);

4134 4135
  int *end = bmGs + pattern_len;
  int *k;
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  for (k = bmGs; k < end; k++)
    *k = pattern_len;

  int tmp;
  int i;
  int j          = 0;
  const int plm1 = pattern_len - 1;
  for (i = plm1; i > -1; i--)
  {
    if (suff[i] == i + 1)
    {
      for (tmp = plm1 - i; j < tmp; j++)
      {
4149
	int *tmp2 = bmGs + j;
4150 4151 4152 4153 4154 4155
	if (*tmp2 == pattern_len)
	  *tmp2 = tmp;
      }
    }
  }

4156
  int *tmp2;
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  for (tmp = plm1 - i; j < tmp; j++)
  {
    tmp2 = bmGs + j;
    if (*tmp2 == pattern_len)
      *tmp2 = tmp;
  }

  tmp2 = bmGs + plm1;
  for (i = 0; i <= pattern_len - 2; i++)
    *(tmp2 - suff[i]) = plm1 - i;
}


/**********************************************************************
   turboBM_compute_bad_character_shifts()
   Precomputation dependent on pattern_len.
**********************************************************************/

void Item_func_like::turboBM_compute_bad_character_shifts()
{
4177 4178 4179 4180
  int *i;
  int *end = bmBc + alphabet_size;
  int j;
  const int plm1 = pattern_len - 1;
4181
  CHARSET_INFO	*cs= cmp.cmp_collation.collation;
4182

4183 4184 4185
  for (i = bmBc; i < end; i++)
    *i = pattern_len;

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  if (!cs->sort_order)
4187
  {
4188
    for (j = 0; j < plm1; j++)
4189
      bmBc[(uint) (uchar) pattern[j]] = plm1 - j;
4190
  }
4191
  else
4192
  {
4193
    for (j = 0; j < plm1; j++)
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4194
      bmBc[(uint) likeconv(cs,pattern[j])] = plm1 - j;
4195
  }
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}


/**********************************************************************
  turboBM_matches()
  Search for pattern in text, returns true/false for match/no match
**********************************************************************/

bool Item_func_like::turboBM_matches(const char* text, int text_len) const
{
  register int bcShift;
  register int turboShift;
  int shift = pattern_len;
  int j     = 0;
  int u     = 0;
4211
  CHARSET_INFO	*cs= cmp.cmp_collation.collation;
4212

4213 4214
  const int plm1=  pattern_len - 1;
  const int tlmpl= text_len - pattern_len;
4215 4216

  /* Searching */
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  if (!cs->sort_order)
4218 4219 4220
  {
    while (j <= tlmpl)
    {
4221
      register int i= plm1;
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      while (i >= 0 && pattern[i] == text[i + j])
      {
	i--;
	if (i == plm1 - shift)
4226
	  i-= u;
4227 4228
      }
      if (i < 0)
4229
	return 1;
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      register const int v = plm1 - i;
      turboShift = u - v;
4233
      bcShift    = bmBc[(uint) (uchar) text[i + j]] - plm1 + i;
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      shift      = max(turboShift, bcShift);
      shift      = max(shift, bmGs[i]);
      if (shift == bmGs[i])
	u = min(pattern_len - shift, v);
      else
      {
	if (turboShift < bcShift)
	  shift = max(shift, u + 1);
	u = 0;
      }
4244
      j+= shift;
4245
    }
4246
    return 0;
4247 4248 4249 4250 4251 4252
  }
  else
  {
    while (j <= tlmpl)
    {
      register int i = plm1;
4253
      while (i >= 0 && likeconv(cs,pattern[i]) == likeconv(cs,text[i + j]))
4254 4255 4256
      {
	i--;
	if (i == plm1 - shift)
4257
	  i-= u;
4258 4259
      }
      if (i < 0)
4260
	return 1;
4261 4262 4263

      register const int v = plm1 - i;
      turboShift = u - v;
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      bcShift    = bmBc[(uint) likeconv(cs, text[i + j])] - plm1 + i;
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      shift      = max(turboShift, bcShift);
      shift      = max(shift, bmGs[i]);
      if (shift == bmGs[i])
	u = min(pattern_len - shift, v);
      else
      {
	if (turboShift < bcShift)
	  shift = max(shift, u + 1);
	u = 0;
      }
4275
      j+= shift;
4276
    }
4277
    return 0;
4278 4279
  }
}
4280

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/*
  Make a logical XOR of the arguments.

  SYNOPSIS
    val_int()

  DESCRIPTION
  If either operator is NULL, return NULL.

  NOTE
    As we don't do any index optimization on XOR this is not going to be
    very fast to use.

  TODO (low priority)
    Change this to be optimized as:
      A XOR B   ->  (A) == 1 AND (B) <> 1) OR (A <> 1 AND (B) == 1)
    To be able to do this, we would however first have to extend the MySQL
    range optimizer to handle OR better.
*/

4302 4303
longlong Item_cond_xor::val_int()
{
4304
  DBUG_ASSERT(fixed == 1);
4305 4306 4307
  List_iterator<Item> li(list);
  Item *item;
  int result=0;	
4308
  null_value=0;
4309 4310
  while ((item=li++))
  {
4311 4312 4313 4314 4315 4316
    result^= (item->val_int() != 0);
    if (item->null_value)
    {
      null_value=1;
      return 0;
    }
4317
  }
4318
  return (longlong) result;
4319
}
4320 4321 4322 4323

/*
  Apply NOT transformation to the item and return a new one.

4324
  SYNOPSIS
4325
    neg_transformer()
4326
    thd		thread handler
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  DESCRIPTION
    Transform the item using next rules:
       a AND b AND ...    -> NOT(a) OR NOT(b) OR ...
       a OR b OR ...      -> NOT(a) AND NOT(b) AND ...
       NOT(a)             -> a
       a = b              -> a != b
       a != b             -> a = b
       a < b              -> a >= b
       a >= b             -> a < b
       a > b              -> a <= b
       a <= b             -> a > b
       IS NULL(a)         -> IS NOT NULL(a)
       IS NOT NULL(a)     -> IS NULL(a)

  RETURN
    New item or
    NULL if we cannot apply NOT transformation (see Item::neg_transformer()).
*/

4347
Item *Item_func_not::neg_transformer(THD *thd)	/* NOT(x)  ->  x */
4348
{
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  return args[0];
4350 4351
}

4352 4353

Item *Item_bool_rowready_func2::neg_transformer(THD *thd)
4354
{
4355 4356
  Item *item= negated_item();
  return item;
4357 4358
}

4359 4360 4361

/* a IS NULL  ->  a IS NOT NULL */
Item *Item_func_isnull::neg_transformer(THD *thd)
4362
{
4363 4364
  Item *item= new Item_func_isnotnull(args[0]);
  return item;
4365 4366
}

4367 4368 4369

/* a IS NOT NULL  ->  a IS NULL */
Item *Item_func_isnotnull::neg_transformer(THD *thd)
4370
{
4371 4372
  Item *item= new Item_func_isnull(args[0]);
  return item;
4373 4374
}

4375 4376 4377

Item *Item_cond_and::neg_transformer(THD *thd)	/* NOT(a AND b AND ...)  -> */
					/* NOT a OR NOT b OR ... */
4378
{
4379 4380 4381
  neg_arguments(thd);
  Item *item= new Item_cond_or(list);
  return item;
4382 4383
}

4384 4385 4386

Item *Item_cond_or::neg_transformer(THD *thd)	/* NOT(a OR b OR ...)  -> */
					/* NOT a AND NOT b AND ... */
4387
{
4388 4389 4390
  neg_arguments(thd);
  Item *item= new Item_cond_and(list);
  return item;
4391 4392
}

4393

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Item *Item_func_nop_all::neg_transformer(THD *thd)
{
  /* "NOT (e $cmp$ ANY (SELECT ...)) -> e $rev_cmp$" ALL (SELECT ...) */
  Item_func_not_all *new_item= new Item_func_not_all(args[0]);
  Item_allany_subselect *allany= (Item_allany_subselect*)args[0];
  allany->func= allany->func_creator(FALSE);
  allany->all= !allany->all;
  allany->upper_item= new_item;
  return new_item;
}

Item *Item_func_not_all::neg_transformer(THD *thd)
{
  /* "NOT (e $cmp$ ALL (SELECT ...)) -> e $rev_cmp$" ANY (SELECT ...) */
  Item_func_nop_all *new_item= new Item_func_nop_all(args[0]);
  Item_allany_subselect *allany= (Item_allany_subselect*)args[0];
  allany->all= !allany->all;
  allany->func= allany->func_creator(TRUE);
  allany->upper_item= new_item;
  return new_item;
}

4416
Item *Item_func_eq::negated_item()		/* a = b  ->  a != b */
4417
{
4418
  return new Item_func_ne(args[0], args[1]);
4419 4420
}

4421 4422

Item *Item_func_ne::negated_item()		/* a != b  ->  a = b */
4423
{
4424
  return new Item_func_eq(args[0], args[1]);
4425 4426
}

4427 4428

Item *Item_func_lt::negated_item()		/* a < b  ->  a >= b */
4429
{
4430
  return new Item_func_ge(args[0], args[1]);
4431 4432
}

4433 4434

Item *Item_func_ge::negated_item()		/* a >= b  ->  a < b */
4435
{
4436
  return new Item_func_lt(args[0], args[1]);
4437 4438
}

4439 4440

Item *Item_func_gt::negated_item()		/* a > b  ->  a <= b */
4441
{
4442
  return new Item_func_le(args[0], args[1]);
4443 4444
}

4445 4446

Item *Item_func_le::negated_item()		/* a <= b  ->  a > b */
4447
{
4448
  return new Item_func_gt(args[0], args[1]);
4449 4450
}

4451 4452
// just fake method, should never be called
Item *Item_bool_rowready_func2::negated_item()
4453
{
4454 4455
  DBUG_ASSERT(0);
  return 0;
4456
}
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Item_equal::Item_equal(Item_field *f1, Item_field *f2)
  : Item_bool_func(), const_item(0), eval_item(0), cond_false(0)
{
  const_item_cache= 0;
  fields.push_back(f1);
  fields.push_back(f2);
}

Item_equal::Item_equal(Item *c, Item_field *f)
  : Item_bool_func(), eval_item(0), cond_false(0)
{
  const_item_cache= 0;
  fields.push_back(f);
  const_item= c;
}

4474

4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499
Item_equal::Item_equal(Item_equal *item_equal)
  : Item_bool_func(), eval_item(0), cond_false(0)
{
  const_item_cache= 0;
  List_iterator_fast<Item_field> li(item_equal->fields);
  Item_field *item;
  while ((item= li++))
  {
    fields.push_back(item);
  }
  const_item= item_equal->const_item;
  cond_false= item_equal->cond_false;
}

void Item_equal::add(Item *c)
{
  if (cond_false)
    return;
  if (!const_item)
  {
    const_item= c;
    return;
  }
  Item_func_eq *func= new Item_func_eq(c, const_item);
  func->set_cmp_func();
4500
  func->quick_fix_field();
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  if ((cond_false= !func->val_int()))
    const_item_cache= 1;
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}

void Item_equal::add(Item_field *f)
{
  fields.push_back(f);
}

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uint Item_equal::members()
{
4512
  return fields.elements;
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}


/*
  Check whether a field is referred in the multiple equality 

  SYNOPSIS
    contains()
4521
    field   field whose occurrence is to be checked
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  DESCRIPTION
4524
    The function checks whether field is occurred in the Item_equal object 
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  RETURN VALUES
    1       if nultiple equality contains a reference to field
    0       otherwise    
*/

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bool Item_equal::contains(Field *field)
{
  List_iterator_fast<Item_field> it(fields);
  Item_field *item;
  while ((item= it++))
  {
    if (field->eq(item->field))
        return 1;
  }
  return 0;
}

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/*
  Join members of another Item_equal object  

  SYNOPSIS
    merge()
    item    multiple equality whose members are to be joined
  
  DESCRIPTION
4552
    The function actually merges two multiple equalities.
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    After this operation the Item_equal object additionally contains
    the field items of another item of the type Item_equal.
    If the optional constant items are not equal the cond_false flag is
    set to 1.  
       
  RETURN VALUES
    none    
*/

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void Item_equal::merge(Item_equal *item)
{
  fields.concat(&item->fields);
  Item *c= item->const_item;
  if (c)
  {
    /* 
      The flag cond_false will be set to 1 after this, if 
      the multiple equality already contains a constant and its 
      value is  not equal to the value of c.
    */
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    add(c);
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  }
  cond_false|= item->cond_false;
} 

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/*
  Order field items in multiple equality according to a sorting criteria 

  SYNOPSIS
    sort()
    cmp          function to compare field item 
    arg          context extra parameter for the cmp function
  
  DESCRIPTION
    The function perform ordering of the field items in the Item_equal
    object according to the criteria determined by the cmp callback parameter.
    If cmp(item_field1,item_field2,arg)<0 than item_field1 must be
    placed after item_fiel2.

  IMPLEMENTATION
    The function sorts field items by the exchange sort algorithm.
    The list of field items is looked through and whenever two neighboring
    members follow in a wrong order they are swapped. This is performed
    again and again until we get all members in a right order.
         
  RETURN VALUES
    None    
*/

void Item_equal::sort(Item_field_cmpfunc cmp, void *arg)
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{
  bool swap;
  List_iterator<Item_field> it(fields);
  do
  {
    Item_field *item1= it++;
    Item_field **ref1= it.ref();
    Item_field *item2;

    swap= FALSE;
    while ((item2= it++))
    {
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      Item_field **ref2= it.ref();
      if (cmp(item1, item2, arg) < 0)
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      {
        Item_field *item= *ref1;
        *ref1= *ref2;
        *ref2= item;
        swap= TRUE;
      }
      else
      {
        item1= item2;
        ref1= ref2;
      }
    }
    it.rewind();
  } while (swap);
}

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/*
  Check appearance of new constant items in the multiple equality object

  SYNOPSIS
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    update_const()
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  DESCRIPTION
    The function checks appearance of new constant items among
    the members of multiple equalities. Each new constant item is
    compared with the designated constant item if there is any in the
    multiple equality. If there is none the first new constant item
    becomes designated.
      
  RETURN VALUES
    none    
*/

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void Item_equal::update_const()
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{
  List_iterator<Item_field> it(fields);
  Item *item;
  while ((item= it++))
  {
    if (item->const_item())
    {
      it.remove();
      add(item);
    }
  }
}

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bool Item_equal::fix_fields(THD *thd, Item **ref)
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{
  List_iterator_fast<Item_field> li(fields);
  Item *item;
  not_null_tables_cache= used_tables_cache= 0;
  const_item_cache= 0;
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  while ((item= li++))
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  {
    table_map tmp_table_map;
    used_tables_cache|= item->used_tables();
    tmp_table_map= item->not_null_tables();
    not_null_tables_cache|= tmp_table_map;
    if (item->maybe_null)
      maybe_null=1;
  }
  fix_length_and_dec();
  fixed= 1;
  return 0;
}

void Item_equal::update_used_tables()
{
  List_iterator_fast<Item_field> li(fields);
  Item *item;
  not_null_tables_cache= used_tables_cache= 0;
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  if ((const_item_cache= cond_false))
    return;
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  while ((item=li++))
  {
    item->update_used_tables();
    used_tables_cache|= item->used_tables();
    const_item_cache&= item->const_item();
  }
}

longlong Item_equal::val_int()
{
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  Item_field *item_field;
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  if (cond_false)
    return 0;
  List_iterator_fast<Item_field> it(fields);
  Item *item= const_item ? const_item : it++;
  if ((null_value= item->null_value))
    return 0;
  eval_item->store_value(item);
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  while ((item_field= it++))
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  {
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    /* Skip fields of non-const tables. They haven't been read yet */
    if (item_field->field->table->const_table)
    {
      if ((null_value= item_field->null_value) || eval_item->cmp(item_field))
        return 0;
    }
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  }
  return 1;
}

void Item_equal::fix_length_and_dec()
{
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  Item *item= get_first();
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  eval_item= cmp_item::get_comparator(item->result_type(),
                                      item->collation.collation);
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}

bool Item_equal::walk(Item_processor processor, byte *arg)
{
  List_iterator_fast<Item_field> it(fields);
  Item *item;
  while ((item= it++))
    if (item->walk(processor, arg))
      return 1;
  return Item_func::walk(processor, arg);
}

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Item *Item_equal::transform(Item_transformer transformer, byte *arg)
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{
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  List_iterator<Item_field> it(fields);
  Item *item;
  while ((item= it++))
  {
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    Item *new_item= item->transform(transformer, arg);
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    if (!new_item)
      return 0;
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    /*
      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.
    */
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    if (new_item != item)
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      current_thd->change_item_tree((Item **) it.ref(), new_item);
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  }
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  return Item_func::transform(transformer, arg);
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}

void Item_equal::print(String *str)
{
  str->append(func_name());
  str->append('(');
  List_iterator_fast<Item_field> it(fields);
  Item *item;
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  if (const_item)
    const_item->print(str);
  else
  {
    item= it++;
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    item->print(str);
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  }
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  while ((item= it++))
  {
    str->append(',');
    str->append(' ');
    item->print(str);
  }
  str->append(')');
}