Question

DEALLOCATE 语句用于为服务器端预处理语句提供 SQL 接口。

语法图

DeallocateStmt:

DeallocateSym:

Identifier:

示例

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

Query OK, 0 rows affected (0.00 sec)

SET @number = 5;

Query OK, 0 rows affected (0.00 sec)

EXECUTE mystmt USING @number;

+------+
| num  |
+------+
| 5    |
+------+
1 row in set (0.00 sec)

DEALLOCATE PREPARE mystmt;

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，请在 GitHub 上提交 issue。

另请参阅

• PREPARE
• EXECUTE