DEALLOCATE

DEALLOCATE 语句提供了一个用于服务器端预处理语句的 SQL 接口。

语法概述

DeallocateStmt ::=
    DeallocateSym 'PREPARE' Identifier

DeallocateSym ::=
    'DEALLOCATE'
|   'DROP'

Identifier ::=
    identifier
|   UnReservedKeyword
|   NotKeywordToken
|   TiDBKeyword

示例

mysql> PREPARE mystmt FROM 'SELECT ? as num FROM DUAL';
Query OK, 0 rows affected (0.00 sec)

mysql> SET @number = 5;
Query OK, 0 rows affected (0.00 sec)

mysql> EXECUTE mystmt USING @number;
+------+
| num  |
+------+
| 5    |
+------+
1 row in set (0.00 sec)

mysql> DEALLOCATE PREPARE mystmt;
Query OK, 0 rows affected (0.00 sec)

MySQL 兼容性

TiDB 中的 DEALLOCATE 语句与 MySQL 完全兼容。如果你发现任何兼容性差异，请报告一个 bug。

相关链接

• PREPARE
• EXECUTE