SCRUM

prepared statements in embedded library


include/mysql.h:
  stmt_execute 'virtual' method added
include/sql_common.h:
  two functions became global
libmysql/client_settings.h:
  declaration for cli_stmt_execute
libmysql/libmysql.c:
  some functions changed to be usable from embedded library
libmysqld/lib_sql.cc:
  code for embedded stmt_execute added
sql-common/client.c:
  cli_stmt_execute added to the methods table
sql/client_settings.h:
  no need for prepared statements in miniclient

include/mysql.h

@@ -560,6 +560,7 @@ typedef struct st_mysql_methods
 				MYSQL_ROW column, uint field_count);
   MYSQL_FIELD * (STDCALL *list_fields)(MYSQL *mysql);
   my_bool (STDCALL *read_prepare_result)(MYSQL *mysql, MYSQL_STMT *stmt);
+  int (STDCALL *stmt_execute)(MYSQL_STMT *stmt);
 } MYSQL_METHODS;
 
 MYSQL_STMT * STDCALL mysql_prepare(MYSQL * mysql, const char *query,

include/sql_common.h

@@ -34,6 +34,13 @@ void end_server(MYSQL *mysql);
 my_bool mysql_reconnect(MYSQL *mysql);
 void mysql_read_default_options(struct st_mysql_options *options,
 				const char *filename,const char *group);
+my_bool STDCALL
+cli_advanced_command(MYSQL *mysql, enum enum_server_command command,
+		     const char *header, ulong header_length,
+		     const char *arg, ulong arg_length, my_bool skip_check);
+
+void set_stmt_errmsg(MYSQL_STMT * stmt, const char *err, int errcode,
+		     const char *sqlstate);
 #ifdef	__cplusplus
 }
 #endif

libmysql/client_settings.h

@@ -54,3 +54,4 @@ MYSQL_FIELD * STDCALL cli_list_fields(MYSQL *mysql);
 my_bool STDCALL cli_read_prepare_result(MYSQL *mysql, MYSQL_STMT *stmt);
 MYSQL_DATA *cli_read_rows(MYSQL *mysql,MYSQL_FIELD *mysql_fields,
 			  uint fields);
+int STDCALL cli_stmt_execute(MYSQL_STMT *stmt);

libmysql/libmysql.c

@@ -1494,8 +1494,8 @@ static void set_stmt_error(MYSQL_STMT * stmt, int errcode,
   Copy error message to statement handler
 */
 
-static void set_stmt_errmsg(MYSQL_STMT * stmt, const char *err, int errcode,
-			    const char *sqlstate)
+void set_stmt_errmsg(MYSQL_STMT * stmt, const char *err, int errcode,
+		     const char *sqlstate)
 {
   DBUG_ENTER("set_stmt_error_msg");
   DBUG_PRINT("enter", ("error: %d/%s '%s'", errcode, sqlstate, err));
@@ -1601,6 +1601,16 @@ my_bool STDCALL cli_read_prepare_result(MYSQL *mysql, MYSQL_STMT *stmt)
   }
   stmt->field_count=  (uint) field_count;
   stmt->param_count=  (ulong) param_count;
+  if (!(stmt->params= (MYSQL_BIND *) alloc_root(&stmt->mem_root,
+						sizeof(MYSQL_BIND)*
+                                                (stmt->param_count + 
+                                                 stmt->field_count))))
+  {
+    set_stmt_error(stmt, CR_OUT_OF_MEMORY, unknown_sqlstate);
+    DBUG_RETURN(1);
+  }
+  stmt->bind= stmt->params + stmt->param_count;
+
   DBUG_RETURN(0);
 }
 
@@ -1649,12 +1659,6 @@ mysql_prepare(MYSQL  *mysql, const char *query, ulong length)
     stmt_close(stmt, 1);
     DBUG_RETURN(0);
   }
-  if (!(stmt->params= (MYSQL_BIND *) alloc_root(&stmt->mem_root,
-						sizeof(MYSQL_BIND)*
-                                                (stmt->param_count + 
-                                                 stmt->field_count))))
-    set_stmt_error(stmt, CR_OUT_OF_MEMORY, unknown_sqlstate);
-  stmt->bind= stmt->params + stmt->param_count;
 
   stmt->state= MY_ST_PREPARE;
   stmt->mysql= mysql;
@@ -1975,36 +1979,21 @@ static my_bool execute(MYSQL_STMT * stmt, char *packet, ulong length)
 
   mysql->last_used_con= mysql;
   int4store(buff, stmt->stmt_id);		/* Send stmt id to server */
-  if ((*mysql->methods->advanced_command)(mysql, COM_EXECUTE, buff, 
-					  MYSQL_STMT_HEADER, packet, 
-					  length, 1) ||
+  if (cli_advanced_command(mysql, COM_EXECUTE, buff, 
+			    MYSQL_STMT_HEADER, packet, 
+			    length, 1) ||
       mysql_read_query_result(mysql))
   {
     set_stmt_errmsg(stmt, net->last_error, net->last_errno, net->sqlstate);
     DBUG_RETURN(1);
   }
-  stmt->state= MY_ST_EXECUTE;
-  mysql_free_result(stmt->result);
-  stmt->result= (MYSQL_RES *)0;
-  stmt->result_buffered= 0;
-  stmt->current_row= 0;
   DBUG_RETURN(0);
 }
 
-
-/*
-  Execute the prepare query
-*/
-
-int STDCALL mysql_execute(MYSQL_STMT *stmt)
+int STDCALL cli_stmt_execute(MYSQL_STMT *stmt)
 {
-  DBUG_ENTER("mysql_execute");
+  DBUG_ENTER("cli_stmt_execute");
 
-  if (stmt->state == MY_ST_UNKNOWN)
-  {
-    set_stmt_error(stmt, CR_NO_PREPARE_STMT, unknown_sqlstate);
-    DBUG_RETURN(1);
-  }
   if (stmt->param_count)
   {
     NET        *net= &stmt->mysql->net;
@@ -2065,6 +2054,30 @@ int STDCALL mysql_execute(MYSQL_STMT *stmt)
   DBUG_RETURN((int) execute(stmt,0,0));
 }
 
+/*
+  Execute the prepare query
+*/
+
+int STDCALL mysql_execute(MYSQL_STMT *stmt)
+{
+  DBUG_ENTER("mysql_execute");
+
+  if (stmt->state == MY_ST_UNKNOWN)
+  {
+    set_stmt_error(stmt, CR_NO_PREPARE_STMT, unknown_sqlstate);
+    DBUG_RETURN(1);
+  }
+  if ((*stmt->mysql->methods->stmt_execute)(stmt))
+    DBUG_RETURN(1);
+      
+  stmt->state= MY_ST_EXECUTE;
+  mysql_free_result(stmt->result);
+  stmt->result= (MYSQL_RES *)0;
+  stmt->result_buffered= 0;
+  stmt->current_row= 0;
+  DBUG_RETURN(0);
+}
+
 
 /*
   Return total parameters count in the statement

libmysqld/lib_sql.cc

@@ -100,7 +100,18 @@ emb_read_rows(MYSQL *mysql, MYSQL_FIELD *mysql_fields __attribute__((unused)),
 {
   MYSQL_DATA *result= ((THD*)mysql->thd)->data;
   if (!result)
-    return NULL;
+  {
+    if (!(result=(MYSQL_DATA*) my_malloc(sizeof(MYSQL_DATA),
+					 MYF(MY_WME | MY_ZEROFILL))))
+    {
+      NET *net = &mysql->net;
+      net->last_errno=CR_OUT_OF_MEMORY;
+      strmov(net->sqlstate, unknown_sqlstate);
+      strmov(net->last_error,ER(net->last_errno));
+      return NULL;
+    }    
+    return result;
+  }
   *result->prev_ptr= NULL;
   ((THD*)mysql->thd)->data= NULL;
   return result;
@@ -126,6 +137,16 @@ static my_bool STDCALL emb_read_prepare_result(MYSQL *mysql, MYSQL_STMT *stmt)
     stmt->fields= mysql->fields;
     stmt->mem_root= mysql->field_alloc;
   }
+
+  if (!(stmt->bind= 
+	(MYSQL_BIND *) alloc_root(&stmt->mem_root,
+				  sizeof(MYSQL_BIND)*stmt->field_count)))
+  {
+    set_stmt_error(stmt, CR_OUT_OF_MEMORY, unknown_sqlstate);
+    return 1;
+  }
+  stmt->params= NULL; // we don't need parameter's buffer in embedded library
+
   return 0;
 }
 
@@ -154,6 +175,23 @@ static my_bool STDCALL emb_mysql_read_query_result(MYSQL *mysql)
   return 0;
 }
 
+static int STDCALL emb_stmt_execute(MYSQL_STMT *stmt)
+{
+  DBUG_ENTER("emb_stmt_execute");
+  THD *thd= (THD*)stmt->mysql->thd;
+  thd->client_param_count= stmt->param_count;
+  thd->client_parameters= stmt->params;
+  if (emb_advanced_command(stmt->mysql, COM_EXECUTE,0,0,
+			   (const char*)&stmt->stmt_id,sizeof(stmt->stmt_id),1)
+      || emb_mysql_read_query_result(stmt->mysql))
+  {
+    NET *net= &stmt->mysql->net;
+    set_stmt_errmsg(stmt, net->last_error, net->last_errno, net->sqlstate);
+    DBUG_RETURN(1);
+  }
+  DBUG_RETURN(0);
+}
+
 MYSQL_METHODS embedded_methods= 
 {
   emb_mysql_read_query_result,
@@ -162,7 +200,8 @@ MYSQL_METHODS embedded_methods=
   mysql_store_result,
   emb_fetch_lengths, 
   emb_list_fields,
-  emb_read_prepare_result
+  emb_read_prepare_result,
+  emb_stmt_execute
 };
 
 C_MODE_END

sql-common/client.c

@@ -636,10 +636,10 @@ void free_rows(MYSQL_DATA *cur)
   }
 }
 
-static my_bool STDCALL
+my_bool STDCALL
 cli_advanced_command(MYSQL *mysql, enum enum_server_command command,
-		 const char *header, ulong header_length,
-		 const char *arg, ulong arg_length, my_bool skip_check)
+		     const char *header, ulong header_length,
+		     const char *arg, ulong arg_length, my_bool skip_check)
 {
   NET *net= &mysql->net;
   my_bool result= 1;
@@ -1407,7 +1407,8 @@ static MYSQL_METHODS client_methods=
   cli_mysql_use_result,
   cli_fetch_lengths,
   cli_list_fields,
-  cli_read_prepare_result
+  cli_read_prepare_result,
+  cli_stmt_execute
 };
 
 MYSQL * STDCALL 

sql/client_settings.h

@@ -34,4 +34,5 @@
 
 #define cli_list_fields NULL
 #define cli_read_prepare_result NULL
+#define cli_stmt_execute NULL