Many files:

  SQL Syntax for Prepared Statements (WL#1622)
ps.test, ps.result:
  new file

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=NULL;
+execute stmt5 using @nullvar;
+? + a
+NULL
+NULL
+NULL
+NULL
+NULL
+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=NULL;
+execute stmt5 using @nullvar;
+
+drop table t1;
+

sql/item.cc

@@ -610,16 +610,21 @@ 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;
   DBUG_PRINT("info", ("string: %s", str_value.ptr()));
   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)
 { 

sql/item.h

@@ -385,6 +385,7 @@ public:
   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

@@ -131,6 +131,7 @@ 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)},
@@ -320,6 +321,7 @@ 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

@@ -604,8 +604,11 @@ 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);
+class Prepared_statement;
+Prepared_statement *mysql_stmt_prepare(THD *thd, char *packet, 
+                                       uint packet_length, bool text_protocol=false);
 void mysql_stmt_execute(THD *thd, char *packet, uint packet_length);
+void mysql_sql_stmt_execute(THD *thd, Prepared_statement *stmt);
 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

@@ -4805,6 +4805,9 @@ 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

@@ -78,6 +78,23 @@ extern "C" void free_user_var(user_var_entry *entry)
   my_free((char*) entry,MYF(0));
 }
 
+/****************************************************************************
+** SQL syntax names for Prepared Statements
+****************************************************************************/
+
+extern "C" byte *get_stmt_key(SQL_PREP_STMT_ENTRY *entry, uint *length,
+			     my_bool not_used __attribute__((unused)))
+{
+  *length=(uint) entry->name.length;
+  return (byte*) entry->name.str;
+}
+
+extern "C" void free_sql_stmt(SQL_PREP_STMT_ENTRY *entry)
+{
+  char *pos= (char*) entry+ALIGN_SIZE(sizeof(*entry));
+  my_free((char*) entry,MYF(0));
+}
+
 
 /****************************************************************************
 ** Thread specific functions
@@ -161,6 +178,9 @@ THD::THD():user_time(0), current_statement(0), is_fatal_error(0),
   else
     bzero((char*) &user_var_events, sizeof(user_var_events));
   
+  hash_init(&sql_prepared_stmts, &my_charset_bin, USER_VARS_HASH_SIZE, 0, 0,
+	    (hash_get_key) get_stmt_key,
+	    (hash_free_key) free_sql_stmt,0);
   /* Protocol */
   protocol= &protocol_simple;			// Default protocol
   protocol_simple.init(this);
@@ -279,6 +299,7 @@ void THD::cleanup(void)
   my_free((char*) variables.datetime_format, MYF(MY_ALLOW_ZERO_PTR));
   delete_dynamic(&user_var_events);
   hash_free(&user_vars);
+  hash_free(&sql_prepared_stmts);
   if (global_read_lock)
     unlock_global_read_lock(this);
   if (ull)

sql/sql_class.h

@@ -594,6 +594,12 @@ public:
   struct  system_variables variables;	// Changeable local variables
   pthread_mutex_t LOCK_delete;		// Locked before thd is deleted
 
+  /* 
+    statement_name -> (Statement*) map of statements prepared using SQL syntax.
+    Hash element is SQL_PREP_STMT_ENTRY.
+  */
+  HASH    sql_prepared_stmts;
+
   /* all prepared statements and cursors of this connection */
   Statement_map stmt_map; 
   /*
@@ -1269,6 +1275,14 @@ class user_var_entry
   DTCollation collation;
 };
 
+class Prepared_statement;
+/* Needed by THD::sql_prepared_stmts */
+typedef struct st_sql_prep_stmt_entry
+{
+ public:
+  LEX_STRING name;
+  Prepared_statement *stmt;
+}SQL_PREP_STMT_ENTRY;
 
 /* Class for unique (removing of duplicates) */
 

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
 };
@@ -583,6 +584,11 @@ 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

@@ -1956,7 +1956,91 @@ mysql_execute_command(THD *thd)
     }
     break;
   }
+  case SQLCOM_PREPARE:
+  {    
+    char *stmt_name= lex->prepared_stmt_name.str;
+    uint name_len=   lex->prepared_stmt_name.length;
+    Prepared_statement *stmt;
+    SQL_PREP_STMT_ENTRY *entry;
+    DBUG_PRINT("info", ("PREPARE: %.*s FROM '%.*s' \n", name_len, stmt_name,
+                        lex->prepared_stmt_code.length,
+                        lex->prepared_stmt_code.str));
+    if ((entry=(SQL_PREP_STMT_ENTRY*)hash_search(&thd->sql_prepared_stmts,
+                                                 (byte*)stmt_name, name_len)))
+    {
+      /* Free the statement with the same name and reuse hash entry */
+      thd->stmt_map.erase((Statement*)entry->stmt);
+    }
+    else
+    {
+      uint size=ALIGN_SIZE(sizeof(SQL_PREP_STMT_ENTRY))+name_len+1;
+      if (!hash_inited(&thd->sql_prepared_stmts) || 
+          !(entry= (SQL_PREP_STMT_ENTRY*)my_malloc(size,MYF(MY_WME))))
+      {
+        send_error(thd, ER_OUT_OF_RESOURCES);
+        break;
+      }
+      entry->name.str= (char*)entry + ALIGN_SIZE(sizeof(SQL_PREP_STMT_ENTRY));
+      entry->name.length= name_len;
+      memcpy(entry->name.str, stmt_name, name_len+1);
+      if (my_hash_insert(&thd->sql_prepared_stmts, (byte*)entry))
+      {
+        my_free((char*)entry,MYF(0));
+        send_error(thd, ER_OUT_OF_RESOURCES);
+        break;
+      }
+    }
+    /* Pretend this is a COM_PREPARE query so parser allows placeholders etc*/
+    thd->command= COM_PREPARE;
+    /* 'length+1' is for alloc_query that strips the last character */
+    stmt= mysql_stmt_prepare(thd, lex->prepared_stmt_code.str,
+                             lex->prepared_stmt_code.length + 1, true);
+    if (stmt)
+    {
+      entry->stmt= stmt;
+      send_ok(thd, 0L, 0L, "Statement prepared");
+    }
+    else
+      hash_delete(&thd->sql_prepared_stmts, (byte*)entry);
+    break;
+  }
+  case SQLCOM_EXECUTE:
+  {
+    char *stmt_name= lex->prepared_stmt_name.str;
+    uint name_len=   lex->prepared_stmt_name.length;
+    SQL_PREP_STMT_ENTRY *entry;
+    DBUG_PRINT("info", ("EXECUTE: %.*s\n", name_len, stmt_name));
     
+    if (!(entry= (SQL_PREP_STMT_ENTRY*)hash_search(&thd->sql_prepared_stmts,
+                                                   (byte*)stmt_name, 
+                                                   name_len)))
+    {
+      send_error(thd, ER_UNKNOWN_STMT_HANDLER, "Undefined prepared statement");
+      lex->prepared_stmt_params.empty();
+      break;
+    }
+    mysql_sql_stmt_execute(thd, entry->stmt);
+    lex->prepared_stmt_params.empty();
+    break;
+  }
+  case SQLCOM_DEALLOCATE_PREPARE:
+  {
+    char *stmt_name= lex->prepared_stmt_name.str;
+    uint name_len=   lex->prepared_stmt_name.length;
+    SQL_PREP_STMT_ENTRY *entry;
+    DBUG_PRINT("info", ("DEALLOCATE PREPARE: %.*s\n", name_len, stmt_name));
+    if (!(entry= (SQL_PREP_STMT_ENTRY*)hash_search(&thd->sql_prepared_stmts,
+                                                   (byte*)stmt_name, 
+                                                   name_len)))
+    {
+      send_error(thd, ER_UNKNOWN_STMT_HANDLER, "Undefined prepared statement");
+      break;
+    }
+    thd->stmt_map.erase((Statement*)entry->stmt);
+    hash_delete(&thd->sql_prepared_stmts, (byte*)entry);
+    send_ok(thd);
+    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

@@ -99,6 +99,8 @@ public:
 #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();
@@ -623,6 +625,120 @@ static bool emb_insert_params_withlog(Prepared_statement *stmt)
 
 #endif /*!EMBEDDED_LIBRARY*/
 
+
+/* 
+  Set prepared statement parameters from user variables.
+  Also replace '?' marks with values in thd->query if binary logging is on.
+  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)))
+    {
+      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->item_result_type= INT_RESULT;
+      param->maybe_null= param->null_value= 1;
+      param->value_is_set= 0;
+    }
+  }
+  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;
+
+  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)))
+    {
+      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->item_result_type= INT_RESULT;
+      param->maybe_null= param->null_value= 1;
+      param->value_is_set= 0;
+      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 the following information for INSERT statement: 
     - field existence
@@ -780,7 +896,8 @@ static int mysql_test_select_fields(Prepared_statement *stmt,
                                     Item *having, ORDER *proc,
                                     ulong select_options, 
                                     SELECT_LEX_UNIT *unit,
-                                    SELECT_LEX *select_lex)
+                                    SELECT_LEX *select_lex,
+                                    bool text_protocol)
 {
   THD *thd= stmt->thd;
   LEX *lex= stmt->lex;
@@ -814,7 +931,7 @@ static int mysql_test_select_fields(Prepared_statement *stmt,
 
   if (lex->describe)
   {
-    if (send_prep_stmt(stmt, 0))
+    if (!text_protocol && send_prep_stmt(stmt, 0))
       goto err;
   }
   else 
@@ -834,6 +951,8 @@ static int mysql_test_select_fields(Prepared_statement *stmt,
       goto err_prep;
     }
 
+    if (!text_protocol)
+    {
       if (send_prep_stmt(stmt, fields.elements) ||
           thd->protocol_simple.send_fields(&fields, 0)
 #ifndef EMBEDDED_LIBRARY
@@ -841,7 +960,7 @@ static int mysql_test_select_fields(Prepared_statement *stmt,
 #endif
          )
         goto err_prep;
-
+    }
     unit->cleanup();
   }
   thd->free_temporary_memory_pool_for_ps_preparing();
@@ -865,7 +984,7 @@ err:
     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;
@@ -905,7 +1024,8 @@ static int send_prepare_results(Prepared_statement *stmt)
                                        select_lex->having,
                                        (ORDER*)lex->proc_list.first,
                                        select_lex->options | thd->options,
-                                       &(lex->unit), select_lex)))
+                                       &(lex->unit), select_lex,
+                                       text_protocol)))
       goto error;
     /* Statement and field info has already been sent */
     DBUG_RETURN(0);
@@ -917,7 +1037,7 @@ static int send_prepare_results(Prepared_statement *stmt)
     */
     break;
   }
-  DBUG_RETURN(send_prep_stmt(stmt, 0));
+  DBUG_RETURN(text_protocol? 0: send_prep_stmt(stmt, 0));
 
 error:
   if (res < 0)
@@ -970,9 +1090,11 @@ 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)
+Prepared_statement *mysql_stmt_prepare(THD *thd, char *packet,
+                                       uint packet_length, bool text_protocol)
 {
   LEX *lex;
   Prepared_statement *stmt= new Prepared_statement(thd);
@@ -982,14 +1104,14 @@ 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(NULL);
   }
 
   if (thd->stmt_map.insert(stmt))
   {
     delete stmt;
     send_error(thd, ER_OUT_OF_RESOURCES);
-    DBUG_VOID_RETURN;
+    DBUG_RETURN(NULL);
   }
 
   thd->stmt_backup.set_statement(thd);
@@ -1006,7 +1128,7 @@ 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(NULL);
   }
 
   mysql_log.write(thd, COM_PREPARE, "%s", packet);
@@ -1018,7 +1140,7 @@ 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, text_protocol);
 
   /* restore to WAIT_PRIOR: QUERY_PRIOR is set inside alloc_query */
   if (!(specialflag & SPECIAL_NO_PRIOR))
@@ -1034,6 +1156,7 @@ 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
@@ -1048,7 +1171,7 @@ 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 */
@@ -1109,7 +1232,6 @@ static void reset_stmt_for_execute(Prepared_statement *stmt)
     mysql_stmt_execute()
 */
 
-
 void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
 {
   ulong stmt_id= uint4korr(packet);
@@ -1181,6 +1303,46 @@ set_params_data_err:
 }
 
 
+/*
+  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, Prepared_statement *stmt)
+{
+  DBUG_ENTER("mysql_stmt_execute");
+  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;
+  }
+  thd->stmt_backup.set_statement(thd);
+  thd->set_statement(stmt);
+  reset_stmt_for_execute(stmt);
+  thd->command= COM_EXECUTE;
+
+  if (stmt->set_params_from_vars(stmt, thd->stmt_backup.lex->
+                                        prepared_stmt_params))
+  {
+    thd->set_statement(&thd->stmt_backup);
+    my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_execute");
+    send_error(thd);
+  }
+
+  if (!(specialflag & SPECIAL_NO_PRIOR))
+    my_pthread_setprio(pthread_self(),QUERY_PRIOR);
+  mysql_execute_command(thd);
+  if (!(specialflag & SPECIAL_NO_PRIOR))
+    my_pthread_setprio(pthread_self(), WAIT_PRIOR);
+
+  cleanup_items(stmt->free_list);
+  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.
@@ -1322,6 +1484,7 @@ 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
@@ -1329,11 +1492,14 @@ 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

@@ -430,6 +430,8 @@ 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
@@ -722,6 +724,7 @@ 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>
@@ -758,10 +761,12 @@ verb_clause:
 	| checksum
 	| commit
 	| create
+        | deallocate 
 	| delete
 	| describe
 	| do
 	| drop
+        | execute 
 	| flush
 	| grant
 	| handler
@@ -773,6 +778,7 @@ verb_clause:
 	| optimize
         | keycache
 	| preload
+        | prepare 
 	| purge
 	| rename
 	| repair
@@ -793,6 +799,72 @@ 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:
@@ -4782,6 +4854,7 @@ keyword:
 	| DATETIME		{}
 	| DATE_SYM		{}
 	| DAY_SYM		{}
+        | DEALLOCATE_SYM        {}
 	| DELAY_KEY_WRITE_SYM	{}
 	| DES_KEY_FILE		{}
 	| DIRECTORY_SYM		{}
@@ -4879,6 +4952,7 @@ keyword:
 	| PASSWORD		{}
 	| POINT_SYM		{}
 	| POLYGON		{}
+        | PREPARE_SYM           {}
 	| PREV_SYM		{}
 	| PROCESS		{}
 	| PROCESSLIST_SYM	{}