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
- DeallocateSym
- Identifier
DeallocateStmt ::=
DeallocateSym 'PREPARE' Identifier
DeallocateSym ::=
'DEALLOCATE'
| 'DROP'
Identifier ::=
identifier
| UnReservedKeyword
| NotKeywordToken
| TiDBKeyword
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，请尝试 TiDB 支持资源。