DEALLOCATE

DEALLOCATE 语句用于为服务器端预处理语句提供 SQL 接口。

语法图

DeallocateStmt

DEALLOCATE - 图1

DeallocateSym

DEALLOCATE - 图2

Identifier

DEALLOCATE - 图3

1. DeallocateStmt ::=
2. DeallocateSym 'PREPARE' Identifier

4. DeallocateSym ::=
5. 'DEALLOCATE'
6. |   'DROP'

8. Identifier ::=
9. identifier
10. |   UnReservedKeyword
11. |   NotKeywordToken
12. |   TiDBKeyword

示例

1. PREPARE mystmt FROM 'SELECT ? as num FROM DUAL';

1. Query OK, 0 rows affected (0.00 sec)

1. SET @number = 5;

1. Query OK, 0 rows affected (0.00 sec)

1. EXECUTE mystmt USING @number;

1. +------+
2. | num  |
3. +------+
4. | 5    |
5. +------+
6. 1 row in set (0.00 sec)

1. DEALLOCATE PREPARE mystmt;

1. Query OK, 0 rows affected (0.00 sec)

MySQL 兼容性

DEALLOCATE 语句与 MySQL 完全兼容。如发现任何兼容性差异，请尝试 TiDB 支持资源。

另请参阅