Manual merge for WL#1622 code, will need fixes

sql/item.cc:
  Auto merged
sql/item.h:
  Auto merged
sql/mysqld.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_prepare.cc:
  Manual merge, will need fixes

mysql-test/r/ps.result

+drop table if exists t1,t2;
+create table t1
+(
+a int primary key,
+b char(10),
+);
+insert into t1 values (1,'one');
+insert into t1 values (2,'two');
+insert into t1 values (3,'three');
+insert into t1 values (4,'four');
+set @a=2;
+prepare stmt1 from 'select * from t1 where a <= ?';
+execute stmt1 using @a;
+a	b
+1	one
+2	two
+set @a=3;
+execute stmt1 using @a;
+a	b
+1	one
+2	two
+3	three
+deallocate prepare no_such_statement;
+ERROR HY000: Undefined prepared statement
+execute stmt1;
+ERROR HY000: Wrong arguments to mysql_execute
+prepare stmt2 from 'prepare nested_stmt from "select 1"';
+ERROR 42000: You have an error in your SQL syntax.  Check the manual that corresponds to your MySQL server version for the right syntax to use near '"select 1"' at line 1
+prepare stmt2 from 'execute stmt1';
+ERROR 42000: You have an error in your SQL syntax.  Check the manual that corresponds to your MySQL server version for the right syntax to use near 'stmt1' at line 1
+prepare stmt2 from 'deallocate prepare z';
+ERROR 42000: You have an error in your SQL syntax.  Check the manual that corresponds to your MySQL server version for the right syntax to use near 'z' at line 1
+prepare stmt3 from 'insert into t1 values (?,?)';
+set @arg1=5, @arg2='five';
+execute stmt3 using @arg1, @arg2;
+select * from t1 where a>3;
+a	b
+4	four
+5	five
+prepare stmt4 from 'update t1 set a=? where b=?';
+set @arg1=55, @arg2='five';
+execute stmt4 using @arg1, @arg2;
+select * from t1 where a>3;
+a	b
+4	four
+55	five
+prepare stmt4 from 'create table t2 (a int)';
+execute stmt4;
+prepare stmt4 from 'drop table t2';
+execute stmt4;
+execute stmt4;
+ERROR 42S02: Unknown table 't2'
+prepare stmt5 from 'select ? + a from t1';
+set @a=1;
+execute stmt5 using @a;
+? + a
+2
+3
+4
+5
+56
+execute stmt5 using @no_such_var;
+? + a
+NULL
+NULL
+NULL
+NULL
+NULL
+set @nullvar=1;
+set @nullvar=NULL;
+execute stmt5 using @nullvar;
+? + a
+NULL
+NULL
+NULL
+NULL
+NULL
+set @nullvar2=NULL;
+execute stmt5 using @nullvar2;
+? + a
+NULL
+NULL
+NULL
+NULL
+NULL
+prepare stmt6 from 'select 1; select2';
+ERROR 42000: You have an error in your SQL syntax.  Check the manual that corresponds to your MySQL server version for the right syntax to use near '; select2' at line 1
+prepare stmt6 from 'insert into t1 values (5,"five"); select2';
+ERROR 42000: You have an error in your SQL syntax.  Check the manual that corresponds to your MySQL server version for the right syntax to use near '; select2' at line 1
+explain prepare stmt6 from 'insert into t1 values (5,"five"); select2';
+ERROR 42000: You have an error in your SQL syntax.  Check the manual that corresponds to your MySQL server version for the right syntax to use near 'from 'insert into t1 values (5,"five"); select2'' at line 1
+drop table t1;

mysql-test/t/ps.test

+#
+# SQL Syntax for Prepared Statements test
+#
+--disable_warnings
+drop table if exists t1,t2;
+--enable_warnings
+
+create table t1
+(
+  a int primary key,
+  b char(10),
+);
+insert into t1 values (1,'one');
+insert into t1 values (2,'two');
+insert into t1 values (3,'three');
+insert into t1 values (4,'four');
+
+# basic functionality
+set @a=2;
+prepare stmt1 from 'select * from t1 where a <= ?';
+execute stmt1 using @a;
+set @a=3;
+execute stmt1 using @a;
+
+# non-existant statement
+--error 1243
+deallocate prepare no_such_statement;
+
+--error 1210
+execute stmt1;
+
+# Nesting ps commands is not allowed: 
+--error 1064
+prepare stmt2 from 'prepare nested_stmt from "select 1"';
+
+--error 1064
+prepare stmt2 from 'execute stmt1';
+
+--error 1064
+prepare stmt2 from 'deallocate prepare z';
+
+# PS insert 
+prepare stmt3 from 'insert into t1 values (?,?)';
+set @arg1=5, @arg2='five';
+execute stmt3 using @arg1, @arg2;
+select * from t1 where a>3;
+
+# PS update 
+prepare stmt4 from 'update t1 set a=? where b=?';
+set @arg1=55, @arg2='five';
+execute stmt4 using @arg1, @arg2;
+select * from t1 where a>3;
+
+# PS create/delete
+prepare stmt4 from 'create table t2 (a int)';
+execute stmt4;
+prepare stmt4 from 'drop table t2';
+execute stmt4;
+
+# Do something that will cause error
+--error 1051
+execute stmt4;
+
+# placeholders in result field names.
+prepare stmt5 from 'select ? + a from t1';
+set @a=1;
+execute stmt5 using @a;
+
+execute stmt5 using @no_such_var;
+
+set @nullvar=1;
+set @nullvar=NULL;
+execute stmt5 using @nullvar;
+
+set @nullvar2=NULL;
+execute stmt5 using @nullvar2;
+
+# Check that multiple SQL statements are disabled inside PREPARE
+--error 1064
+prepare stmt6 from 'select 1; select2';
+
+--error 1064
+prepare stmt6 from 'insert into t1 values (5,"five"); select2';
+
+# This shouldn't parse
+--error 1064
+explain prepare stmt6 from 'insert into t1 values (5,"five"); select2';
+
+drop table t1;
+

sql/item.cc

@@ -644,10 +644,10 @@ void Item_param::set_double(double value)
 }
 
 
-void Item_param::set_value(const char *str, uint length)
+void Item_param::set_value(const char *str, uint length, CHARSET_INFO *ci)
 {
   DBUG_ENTER("Item_param::set_value");
-  str_value.copy(str,length,default_charset());
+  str_value.copy(str,length,ci);
   item_type= STRING_ITEM;
   value_is_set= 1;
   maybe_null= 0;
@@ -655,6 +655,11 @@ void Item_param::set_value(const char *str, uint length)
   DBUG_VOID_RETURN;
 }
 
+void Item_param::set_value(const char *str, uint length)
+{
+  set_value(str, length, default_charset());
+}
+
 
 void Item_param::set_time(TIME *tm, timestamp_type type)
 { 
@@ -1528,7 +1533,7 @@ bool Item::send(Protocol *protocol, String *buffer)
   }
   case MYSQL_TYPE_TINY:
   {
-    longlong nr;
+    longlong nr;  
     nr= val_int();
     if (!null_value)
       result= protocol->store_tiny(nr);

sql/item.h

@@ -413,6 +413,7 @@ class Item_param :public Item
   void set_int(longlong i);
   void set_double(double i);
   void set_value(const char *str, uint length);
+  void set_value(const char *str, uint length, CHARSET_INFO *ci);
   void set_long_str(const char *str, ulong length);
   void set_long_binary(const char *str, ulong length);
   void set_longdata(const char *str, ulong length);

sql/lex.h

@@ -133,6 +133,7 @@ static SYMBOL symbols[] = {
   { "DAY_MICROSECOND",	SYM(DAY_MICROSECOND_SYM)},
   { "DAY_MINUTE",	SYM(DAY_MINUTE_SYM)},
   { "DAY_SECOND",	SYM(DAY_SECOND_SYM)},
+  { "DEALLOCATE",       SYM(DEALLOCATE_SYM)},     
   { "DEC",		SYM(DECIMAL_SYM)},
   { "DECIMAL",		SYM(DECIMAL_SYM)},
   { "DEFAULT",		SYM(DEFAULT)},
@@ -324,6 +325,7 @@ static SYMBOL symbols[] = {
   { "POINT",		SYM(POINT_SYM)},
   { "POLYGON",		SYM(POLYGON)},
   { "PRECISION",	SYM(PRECISION)},
+  { "PREPARE",          SYM(PREPARE_SYM)},
   { "PREV",		SYM(PREV_SYM)},
   { "PRIMARY",		SYM(PRIMARY_SYM)},
   { "PRIVILEGES",	SYM(PRIVILEGES)},

sql/mysql_priv.h

@@ -634,8 +634,10 @@ int mysqld_show_column_types(THD *thd);
 int mysqld_help (THD *thd, const char *text);
 
 /* sql_prepare.cc */
-void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length);
+int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length, 
+                       LEX_STRING *name=NULL);
 void mysql_stmt_execute(THD *thd, char *packet, uint packet_length);
+void mysql_sql_stmt_execute(THD *thd, LEX_STRING *stmt_name);
 void mysql_stmt_free(THD *thd, char *packet);
 void mysql_stmt_reset(THD *thd, char *packet);
 void mysql_stmt_get_longdata(THD *thd, char *pos, ulong packet_length);

sql/mysqld.cc

@@ -4822,6 +4822,9 @@ struct show_var_st status_vars[]= {
   {"Com_unlock_tables",	       (char*) (com_stat+(uint) SQLCOM_UNLOCK_TABLES),SHOW_LONG},
   {"Com_update",	       (char*) (com_stat+(uint) SQLCOM_UPDATE),SHOW_LONG},
   {"Com_update_multi",	       (char*) (com_stat+(uint) SQLCOM_UPDATE_MULTI),SHOW_LONG},
+  {"Com_prepare_sql",          (char*) (com_stat+(uint) SQLCOM_PREPARE), SHOW_LONG}, 
+  {"Com_execute_sql",          (char*) (com_stat+(uint) SQLCOM_EXECUTE), SHOW_LONG},
+  {"Com_dealloc_sql",          (char*) (com_stat+(uint) SQLCOM_DEALLOCATE_PREPARE), SHOW_LONG},
   {"Connections",              (char*) &thread_id,              SHOW_LONG_CONST},
   {"Created_tmp_disk_tables",  (char*) &created_tmp_disk_tables,SHOW_LONG},
   {"Created_tmp_files",	       (char*) &my_tmp_file_created,	SHOW_LONG},

sql/sql_class.cc

@@ -78,7 +78,6 @@ extern "C" void free_user_var(user_var_entry *entry)
   my_free((char*) entry,MYF(0));
 }
 
-
 /****************************************************************************
 ** Thread specific functions
 ****************************************************************************/
@@ -160,7 +159,7 @@ THD::THD():user_time(0), current_statement(0), is_fatal_error(0),
 			  16);
   else
     bzero((char*) &user_var_events, sizeof(user_var_events));
-
+  
   /* Protocol */
   protocol= &protocol_simple;			// Default protocol
   protocol_simple.init(this);
@@ -1199,6 +1198,7 @@ Statement::Statement(THD *thd)
   query_length(0),
   free_list(0)
 {
+  name.str= NULL;
   init_sql_alloc(&mem_root,
                  thd->variables.query_alloc_block_size,
                  thd->variables.query_prealloc_size);
@@ -1282,17 +1282,52 @@ static void delete_statement_as_hash_key(void *key)
   delete (Statement *) key;
 }
 
+static byte *get_stmt_name_hash_key(Statement *entry, uint *length,
+                                    my_bool not_used __attribute__((unused)))
+{
+  *length=(uint) entry->name.length;
+  return (byte*) entry->name.str;
+}
+
 C_MODE_END
 
 Statement_map::Statement_map() :
   last_found_statement(0)
 {
-  enum { START_HASH_SIZE = 16 };
-  hash_init(&st_hash, default_charset_info, START_HASH_SIZE, 0, 0,
+  enum
+  {
+    START_STMT_HASH_SIZE = 16,
+    START_NAME_HASH_SIZE = 16
+  };
+  hash_init(&st_hash, default_charset_info, START_STMT_HASH_SIZE, 0, 0,
             get_statement_id_as_hash_key,
             delete_statement_as_hash_key, MYF(0));
+  hash_init(&names_hash, &my_charset_bin, START_NAME_HASH_SIZE, 0, 0,
+            (hash_get_key) get_stmt_name_hash_key,
+            NULL,MYF(0));
 }
 
+int Statement_map::insert(Statement *statement)
+{
+  int rc= my_hash_insert(&st_hash, (byte *) statement);
+  if (rc == 0)
+    last_found_statement= statement;
+  if (statement->name.str)
+  {
+    /*
+      If there is a statement with the same name, remove it. It is ok to 
+      remove old and fail to insert new one at the same time.
+    */
+    Statement *old_stmt;
+    if ((old_stmt= find_by_name(&statement->name)))
+      erase(old_stmt); 
+    if ((rc= my_hash_insert(&names_hash, (byte*)statement)))
+      hash_delete(&st_hash, (byte*)statement);
+  }
+  return rc;
+}
+
+
 bool select_dumpvar::send_data(List<Item> &items)
 {
   List_iterator_fast<Item_func_set_user_var> li(vars);

sql/sql_class.h

@@ -456,6 +456,7 @@ class Statement
   */
   bool allow_sum_func;
 
+  LEX_STRING name; /* name for named prepared statements */
   LEX *lex;                                     // parse tree descriptor
   /*
     Points to the query associated with this statement. It's const, but
@@ -522,8 +523,14 @@ class Statement
 
 
 /*
-  Used to seek all existing statements in the connection
-  Deletes all statements in destructor.
+  Container for all statements created/used in a connection.
+  Statements in Statement_map have unique Statement::id (guaranteed by id
+  assignment in Statement::Statement)
+  Non-empty statement names are unique too: attempt to insert a new statement
+  with duplicate name causes older statement to be deleted
+  
+  Statements are auto-deleted when they are removed from the map and when the
+  map is deleted.
 */
 
 class Statement_map
@@ -531,12 +538,14 @@ class Statement_map
 public:
   Statement_map();
   
-  int insert(Statement *statement)
+  int insert(Statement *statement);
+
+  Statement *find_by_name(LEX_STRING *name)
   {
-    int rc= my_hash_insert(&st_hash, (byte *) statement);
-    if (rc == 0)
-      last_found_statement= statement;
-    return rc;
+    Statement *stmt;
+    stmt= (Statement*)hash_search(&names_hash, (byte*)name->str,
+                                  name->length);
+    return stmt;
   }
 
   Statement *find(ulong id)
@@ -550,15 +559,21 @@ class Statement_map
   {
     if (statement == last_found_statement)
       last_found_statement= 0;
+    if (statement->name.str)
+    {
+      hash_delete(&names_hash, (byte *) statement);  
+    }
     hash_delete(&st_hash, (byte *) statement);
   }
 
   ~Statement_map()
   {
     hash_free(&st_hash);
+    hash_free(&names_hash);
   }
 private:
   HASH st_hash;
+  HASH names_hash;
   Statement *last_found_statement;
 };
 

sql/sql_lex.h

@@ -76,6 +76,7 @@ enum enum_sql_command {
   SQLCOM_SHOW_COLUMN_TYPES, SQLCOM_SHOW_STORAGE_ENGINES, SQLCOM_SHOW_PRIVILEGES,
   SQLCOM_HELP, SQLCOM_DROP_USER, SQLCOM_REVOKE_ALL, SQLCOM_CHECKSUM,
 
+  SQLCOM_PREPARE, SQLCOM_EXECUTE, SQLCOM_DEALLOCATE_PREPARE,
   /* This should be the last !!! */
   SQLCOM_END
 };
@@ -592,6 +593,11 @@ typedef struct st_lex
   bool in_comment, ignore_space, verbose, simple_alter, no_write_to_binlog;
   bool derived_tables;
   bool safe_to_cache_query;
+  /* Prepared statements SQL syntax:*/
+  LEX_STRING prepared_stmt_name; /* Statement name (in all queries) */
+  LEX_STRING prepared_stmt_code; /* Statement query (in PREPARE )*/
+  /* Names of user variables holding parameters (in EXECUTE) */
+  List<LEX_STRING> prepared_stmt_params; 
   st_lex() {}
   inline void uncacheable(uint8 cause)
   {

sql/sql_parse.cc

@@ -1964,7 +1964,44 @@ mysql_execute_command(THD *thd)
     }
     break;
   }
-
+  case SQLCOM_PREPARE:
+  {   
+    DBUG_PRINT("info", ("PREPARE: %.*s FROM '%.*s' \n", 
+                        lex->prepared_stmt_name.length,
+                        lex->prepared_stmt_name.str,
+                        lex->prepared_stmt_code.length,
+                        lex->prepared_stmt_code.str));
+    thd->command= COM_PREPARE;
+    if (!mysql_stmt_prepare(thd, lex->prepared_stmt_code.str,
+                            lex->prepared_stmt_code.length + 1, 
+                            &lex->prepared_stmt_name))    
+      send_ok(thd, 0L, 0L, "Statement prepared");
+    break;
+  }
+  case SQLCOM_EXECUTE:
+  {
+    DBUG_PRINT("info", ("EXECUTE: %.*s\n", 
+                        lex->prepared_stmt_name.length,
+                        lex->prepared_stmt_name.str));
+    mysql_sql_stmt_execute(thd, &lex->prepared_stmt_name);
+    lex->prepared_stmt_params.empty();
+    break;
+  }
+  case SQLCOM_DEALLOCATE_PREPARE:
+  {
+    Statement* stmt;
+    DBUG_PRINT("info", ("DEALLOCATE PREPARE: %.*s\n", 
+                        lex->prepared_stmt_name.length,
+                        lex->prepared_stmt_name.str));
+    if ((stmt= thd->stmt_map.find_by_name(&lex->prepared_stmt_name)))
+    {
+      thd->stmt_map.erase(stmt);
+      send_ok(thd);
+    }
+    else
+      send_error(thd,ER_UNKNOWN_STMT_HANDLER,"Undefined prepared statement");
+    break;
+  }
   case SQLCOM_DO:
     if (tables && ((res= check_table_access(thd, SELECT_ACL, tables,0)) ||
 		   (res= open_and_lock_tables(thd,tables))))

sql/sql_prepare.cc

@@ -98,12 +98,15 @@ class Prepared_statement: public Statement
 #else
   bool (*set_params_data)(Prepared_statement *st);
 #endif
+  bool (*set_params_from_vars)(Prepared_statement *stmt, 
+                               List<LEX_STRING>& varnames);
 public:
   Prepared_statement(THD *thd_arg);
   virtual ~Prepared_statement();
   virtual Statement::Type type() const;
 };
 
+static void execute_stmt(THD *thd, Prepared_statement *stmt);
 
 /******************************************************************************
   Implementation
@@ -639,6 +642,116 @@ static bool emb_insert_params_withlog(Prepared_statement *stmt)
 #endif /*!EMBEDDED_LIBRARY*/
 
 
+/* 
+  Set prepared statement parameters from user variables.
+  SYNOPSIS
+    insert_params_from_vars()
+      stmt      Statement
+      varnames  List of variables. Caller must ensure that number of variables
+                in the list is equal to number of statement parameters
+
+*/
+
+static bool insert_params_from_vars(Prepared_statement *stmt, 
+                                    List<LEX_STRING>& varnames)
+{
+  Item_param **begin= stmt->param_array;
+  Item_param **end= begin + stmt->param_count;
+  user_var_entry *entry;
+  LEX_STRING *varname;
+  DBUG_ENTER("insert_params_from_vars"); 
+
+  List_iterator<LEX_STRING> var_it(varnames);
+  for (Item_param **it= begin; it < end; ++it)
+  {
+    Item_param *param= *it;
+    varname= var_it++;
+    if ((entry= (user_var_entry*)hash_search(&stmt->thd->user_vars, 
+                                             (byte*) varname->str,
+                                             varname->length))
+        && entry->value)
+    {
+      param->item_result_type= entry->type;
+      switch (entry->type)
+      {
+        case REAL_RESULT:
+          param->set_double(*(double*)entry->value);
+          break;
+        case INT_RESULT:
+          param->set_int(*(longlong*)entry->value);
+          break;
+        case STRING_RESULT:
+          param->set_value(entry->value, entry->length, 
+                           entry->collation.collation);
+          break;
+        default:
+          DBUG_ASSERT(0);
+      }
+    }
+    else
+      param->maybe_null= param->null_value= param->value_is_set= 1;
+  }
+  DBUG_RETURN(0);
+}
+
+static bool insert_params_from_vars_with_log(Prepared_statement *stmt,
+                                             List<LEX_STRING>& varnames)
+{
+  Item_param **begin= stmt->param_array;
+  Item_param **end= begin + stmt->param_count;
+  user_var_entry *entry;
+  LEX_STRING *varname;
+  DBUG_ENTER("insert_params_from_vars"); 
+
+  List_iterator<LEX_STRING> var_it(varnames);
+  String str, query;
+  const String *res;
+  uint32 length= 0;
+  if (query.copy(stmt->query, stmt->query_length, default_charset_info))
+    DBUG_RETURN(1);
+
+  for (Item_param **it= begin; it < end; ++it)
+  {
+    Item_param *param= *it;
+    varname= var_it++;
+    if ((entry= (user_var_entry*)hash_search(&stmt->thd->user_vars, 
+                                             (byte*) varname->str,
+                                             varname->length))
+        && entry->value)
+    {
+      param->item_result_type= entry->type;
+      switch (entry->type)
+      {
+        case REAL_RESULT:
+          param->set_double(*(double*)entry->value);
+          break;
+        case INT_RESULT:
+          param->set_int(*(longlong*)entry->value);
+          break;
+        case STRING_RESULT:
+          param->set_value(entry->value, entry->length, 
+                           entry->collation.collation);
+          break;
+        default:
+          DBUG_ASSERT(0);
+      }
+      res= param->query_val_str(&str);
+    }
+    else
+    {
+      param->maybe_null= param->null_value= param->value_is_set= 1;
+      res= &my_null_string;
+    }
+
+    if (query.replace(param->pos_in_query+length, 1, *res))
+      DBUG_RETURN(1);
+    length+= res->length()-1;
+  }
+  if (alloc_query(stmt->thd, (char *) query.ptr(), query.length()+1))
+    DBUG_RETURN(1);
+  DBUG_RETURN(0);
+}
+
 /*
   Validate INSERT statement: 
 
@@ -835,7 +948,7 @@ static int mysql_test_delete(Prepared_statement *stmt,
 */
 
 static int mysql_test_select(Prepared_statement *stmt,
-			     TABLE_LIST *tables)
+			     TABLE_LIST *tables, bool text_protocol)
 {
   THD *thd= stmt->thd;
   LEX *lex= stmt->lex;
@@ -867,7 +980,7 @@ static int mysql_test_select(Prepared_statement *stmt,
 
   if (lex->describe)
   {
-    if (send_prep_stmt(stmt, 0))
+    if (!text_protocol && send_prep_stmt(stmt, 0))
       goto err;
   }
   else
@@ -881,14 +994,16 @@ static int mysql_test_select(Prepared_statement *stmt,
       goto err_prep;
     }
 
-    if (send_prep_stmt(stmt, lex->select_lex.item_list.elements) ||
+    if (!text_protocol)
+    {
+      if (send_prep_stmt(stmt, lex->select_lex.item_list.elements) ||
         thd->protocol_simple.send_fields(&lex->select_lex.item_list, 0)
 #ifndef EMBEDDED_LIBRARY
-        || net_flush(&thd->net)
+          || net_flush(&thd->net)
 #endif
-       )
-      goto err_prep;
-
+         )
+        goto err_prep;
+    }
     unit->cleanup();
   }
   thd->free_temporary_memory_pool_for_ps_preparing();
@@ -1166,7 +1281,7 @@ static int mysql_test_insert_select(Prepared_statement *stmt,
     0   success
     1   error, sent to client
 */
-static int send_prepare_results(Prepared_statement *stmt)
+static int send_prepare_results(Prepared_statement *stmt, bool text_protocol)
 {   
   THD *thd= stmt->thd;
   LEX *lex= stmt->lex;
@@ -1203,7 +1318,7 @@ static int send_prepare_results(Prepared_statement *stmt)
     break;
 
   case SQLCOM_SELECT:
-    if ((res= mysql_test_select(stmt, tables)))
+    if ((res= mysql_test_select(stmt, tables, text_protocol)))
       goto error;
     /* Statement and field info has already been sent */
     DBUG_RETURN(0);
@@ -1261,7 +1376,7 @@ static int send_prepare_results(Prepared_statement *stmt)
     goto error;
   }
   if (res == 0)
-    DBUG_RETURN(send_prep_stmt(stmt, 0));
+    DBUG_RETURN(text_protocol?0:send_prep_stmt(stmt, 0));
 error:
   if (res < 0)
     send_error(thd, thd->killed ? ER_SERVER_SHUTDOWN : 0);
@@ -1302,6 +1417,14 @@ static bool init_param_array(Prepared_statement *stmt)
 
 
 /*
+  SYNOPSIS
+    mysql_stmt_prepare()
+      packet         Prepared query 
+      packet_length  query length, with ignored trailing NULL or quote char.
+      name           NULL or statement name. For unnamed statements binary PS
+                     protocol is used, for named statmenents text protocol is 
+                     used.
+
   Parse the query and send the total number of parameters 
   and resultset metadata information back to client (if any), 
   without executing the query i.e. without any log/disk 
@@ -1313,9 +1436,11 @@ static bool init_param_array(Prepared_statement *stmt)
   list in lex->param_array, so that a fast and direct
   retrieval can be made without going through all field
   items.
+   
 */
 
-void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
+int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
+                       LEX_STRING *name)
 {
   LEX *lex;
   Prepared_statement *stmt= new Prepared_statement(thd);
@@ -1327,14 +1452,26 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
   if (stmt == 0)
   {
     send_error(thd, ER_OUT_OF_RESOURCES);
-    DBUG_VOID_RETURN;
+    DBUG_RETURN(1);
+  }
+
+  if (name)
+  {
+    stmt->name.length= name->length;
+    if (!(stmt->name.str= memdup_root(&stmt->mem_root, (byte*)name->str,
+                                      name->length)))
+    {
+      delete stmt;
+      send_error(thd, ER_OUT_OF_RESOURCES);
+      DBUG_RETURN(1);
+    }
   }
 
   if (thd->stmt_map.insert(stmt))
   {
     delete stmt;
     send_error(thd, ER_OUT_OF_RESOURCES);
-    DBUG_VOID_RETURN;
+    DBUG_RETURN(1);
   }
 
   thd->stmt_backup.set_statement(thd);
@@ -1351,7 +1488,7 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
     /* Statement map deletes statement on erase */
     thd->stmt_map.erase(stmt);
     send_error(thd, ER_OUT_OF_RESOURCES);
-    DBUG_VOID_RETURN;
+    DBUG_RETURN(1);
   }
 
   mysql_log.write(thd, COM_PREPARE, "%s", packet);
@@ -1363,7 +1500,7 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
 
   error= yyparse((void *)thd) || thd->is_fatal_error ||
          init_param_array(stmt) ||
-         send_prepare_results(stmt);
+         send_prepare_results(stmt, test(name));
 
   /* restore to WAIT_PRIOR: QUERY_PRIOR is set inside alloc_query */
   if (!(specialflag & SPECIAL_NO_PRIOR))
@@ -1379,6 +1516,7 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
   {
     /* Statement map deletes statement on erase */
     thd->stmt_map.erase(stmt);
+    stmt= NULL;
     /* error is sent inside yyparse/send_prepare_results */
   }
   else
@@ -1393,7 +1531,7 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
       sl->prep_where= sl->where;
     }
   }
-  DBUG_VOID_RETURN;
+  DBUG_RETURN(!stmt);
 }
 
 /* Reinit statement before execution */
@@ -1472,7 +1610,6 @@ static void reset_stmt_params(Prepared_statement *stmt)
     mysql_stmt_execute()
 */
 
-
 void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
 {
   ulong stmt_id= uint4korr(packet);
@@ -1496,9 +1633,7 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
     DBUG_VOID_RETURN;
   }
 
-  thd->stmt_backup.set_statement(thd);
-  thd->set_statement(stmt);
-  reset_stmt_for_execute(stmt);
+  
 #ifndef EMBEDDED_LIBRARY
   if (stmt->param_count)
   {
@@ -1516,28 +1651,11 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
   if (stmt->param_count && stmt->set_params_data(stmt))
     goto set_params_data_err;
 #endif
-
-  if (!(specialflag & SPECIAL_NO_PRIOR))
-    my_pthread_setprio(pthread_self(),QUERY_PRIOR);
- 
-  /*
-    TODO:
-    Also, have checks on basic executions such as mysql_insert(), 
-    mysql_delete(), mysql_update() and mysql_select() to not to 
-    have re-check on setup_* and other things ..
-  */
   thd->protocol= &thd->protocol_prep;           // Switch to binary protocol
-  mysql_execute_command(thd);
-  thd->lex->unit.cleanup();
+  execute_stmt(thd, stmt);
   thd->protocol= &thd->protocol_simple;         // Use normal protocol
-
-  if (!(specialflag & SPECIAL_NO_PRIOR))
-    my_pthread_setprio(pthread_self(), WAIT_PRIOR);
-
-  cleanup_items(stmt->free_list);
+  //psergey-todo: move this into execute_stmt: 
   reset_stmt_params(stmt);
-  close_thread_tables(thd); // to close derived tables
-  thd->set_statement(&thd->stmt_backup);
   /* 
     Free Items that were created during this execution of the PS by query
     optimizer.
@@ -1546,14 +1664,75 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
   DBUG_VOID_RETURN;
 
 set_params_data_err:
-  reset_stmt_params(stmt);
-  thd->set_statement(&thd->stmt_backup);
+  reset_stmt_params(stmt); //psergey-todo: check if this belongs here
   my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_execute");
   send_error(thd);
   DBUG_VOID_RETURN;
 }
 
 
+/*
+  Execute prepared statement using parameter values from 
+  lex->prepared_stmt_params and send result to the client using text protocol.
+*/
+
+void mysql_sql_stmt_execute(THD *thd, LEX_STRING *stmt_name)
+{
+  Prepared_statement *stmt;
+  DBUG_ENTER("mysql_stmt_execute");
+    
+  if (!(stmt= (Prepared_statement*)thd->stmt_map.find_by_name(stmt_name)))
+  {
+      send_error(thd, ER_UNKNOWN_STMT_HANDLER, 
+                 "Undefined prepared statement");
+      DBUG_VOID_RETURN;
+  }
+
+  if (stmt->param_count != thd->lex->prepared_stmt_params.elements)
+  {
+    my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_execute");
+    send_error(thd);
+    DBUG_VOID_RETURN;
+  }
+  /* Item_param allows setting parameters in COM_EXECUTE only */
+  thd->command= COM_EXECUTE;
+
+  if (stmt->set_params_from_vars(stmt, thd->lex->prepared_stmt_params))
+  {
+    my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_execute");
+    send_error(thd);
+  }
+  execute_stmt(thd, stmt);
+  DBUG_VOID_RETURN;
+}
+
+/*
+  Execute prepared statement.
+  Caller must set parameter values and thd::protocol.
+*/
+static void execute_stmt(THD *thd, Prepared_statement *stmt)
+{
+  DBUG_ENTER("execute_stmt");
+  thd->stmt_backup.set_statement(thd);
+  thd->set_statement(stmt);
+  reset_stmt_for_execute(stmt);
+
+  if (!(specialflag & SPECIAL_NO_PRIOR))
+    my_pthread_setprio(pthread_self(),QUERY_PRIOR);
+  mysql_execute_command(thd);
+  thd->lex->unit.cleanup();
+  if (!(specialflag & SPECIAL_NO_PRIOR))
+    my_pthread_setprio(pthread_self(), WAIT_PRIOR);
+
+  cleanup_items(stmt->free_list);
+  reset_stmt_params(stmt);
+  close_thread_tables(thd); // to close derived tables
+  thd->set_statement(&thd->stmt_backup);
+  DBUG_VOID_RETURN;
+}
+
+
+
 /*
     Reset a prepared statement, in case there was an error in send_longdata.
     Note: we don't send any reply to that command.
@@ -1690,6 +1869,7 @@ Prepared_statement::Prepared_statement(THD *thd_arg)
   if (mysql_bin_log.is_open())
   {
     log_full_query= 1;
+    set_params_from_vars= insert_params_from_vars_with_log;
 #ifndef EMBEDDED_LIBRARY
     set_params= insert_params_withlog;
 #else
@@ -1697,11 +1877,14 @@ Prepared_statement::Prepared_statement(THD *thd_arg)
 #endif
   }
   else
+  {
+    set_params_from_vars= insert_params_from_vars;
 #ifndef EMBEDDED_LIBRARY
     set_params= insert_params;
 #else
     set_params_data= emb_insert_params;
 #endif
+  }
 }
 
 

sql/sql_yacc.yy

@@ -432,6 +432,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %token	MEDIUMTEXT
 %token	NUMERIC_SYM
 %token	PRECISION
+%token  PREPARE_SYM
+%token  DEALLOCATE_SYM
 %token	QUICK
 %token	REAL
 %token	SIGNED_SYM
@@ -724,6 +726,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 	precision subselect_start opt_and charset
 	subselect_end select_var_list select_var_list_init help opt_len
 	opt_extended_describe
+        prepare execute deallocate 
 END_OF_INPUT
 
 %type <NONE>
@@ -760,10 +763,12 @@ verb_clause:
 	| checksum
 	| commit
 	| create
+        | deallocate 
 	| delete
 	| describe
 	| do
 	| drop
+        | execute 
 	| flush
 	| grant
 	| handler
@@ -775,6 +780,7 @@ verb_clause:
 	| optimize
         | keycache
 	| preload
+        | prepare 
 	| purge
 	| rename
 	| repair
@@ -795,6 +801,71 @@ verb_clause:
 	| use
         ;
 
+deallocate:
+        DEALLOCATE_SYM PREPARE_SYM ident 
+        {
+          THD *thd=YYTHD;
+          LEX *lex= thd->lex;
+          if (thd->command == COM_PREPARE)
+          {
+            yyerror(ER(ER_SYNTAX_ERROR));
+            YYABORT;
+          }
+          lex->sql_command= SQLCOM_DEALLOCATE_PREPARE;
+          lex->prepared_stmt_name= $3;
+        };
+
+prepare:
+        PREPARE_SYM ident FROM TEXT_STRING_sys
+        {
+          THD *thd=YYTHD;
+          LEX *lex= thd->lex;
+          if (thd->command == COM_PREPARE)
+          {
+            yyerror(ER(ER_SYNTAX_ERROR));
+            YYABORT;
+          }
+          lex->sql_command= SQLCOM_PREPARE;
+          lex->prepared_stmt_name= $2;
+          lex->prepared_stmt_code= $4;
+        };
+
+execute:
+        EXECUTE_SYM ident
+        {
+          THD *thd=YYTHD;
+          LEX *lex= thd->lex;
+          if (thd->command == COM_PREPARE)
+          {
+            yyerror(ER(ER_SYNTAX_ERROR));
+            YYABORT;
+          }
+          lex->sql_command= SQLCOM_EXECUTE;
+          lex->prepared_stmt_name= $2;
+        }
+        execute_using
+        {}
+        ;
+
+execute_using:
+        /* nothing */
+        | USING execute_var_list
+        ;
+
+execute_var_list:
+        execute_var_list ',' execute_var_ident
+        | execute_var_ident
+        ;
+
+execute_var_ident: '@' ident_or_text
+        {
+          LEX *lex=Lex;
+          LEX_STRING *lexstr= (LEX_STRING*)sql_memdup(&$2, sizeof(LEX_STRING));
+          if (!lexstr || lex->prepared_stmt_params.push_back(lexstr))
+              YYABORT;
+        }
+        ;
+
 /* help */
 
 help:
@@ -4900,6 +4971,7 @@ keyword:
 	| DATETIME		{}
 	| DATE_SYM		{}
 	| DAY_SYM		{}
+        | DEALLOCATE_SYM        {}
 	| DELAY_KEY_WRITE_SYM	{}
 	| DES_KEY_FILE		{}
 	| DIRECTORY_SYM		{}
@@ -4998,6 +5070,7 @@ keyword:
 	| PASSWORD		{}
 	| POINT_SYM		{}
 	| POLYGON		{}
+        | PREPARE_SYM           {}
 	| PREV_SYM		{}
 	| PROCESS		{}
 	| PROCESSLIST_SYM	{}