sql-statement-deallocate.md

title	summary	aliases
DEALLOCATE | TiDB SQL Statement Reference	An overview of the usage of DEALLOCATE for the TiDB database.	/docs/dev/sql-statements/sql-statement-deallocate/ /docs/dev/reference/sql/statements/deallocate/

DEALLOCATE

The DEALLOCATE statement provides an SQL interface to server-side prepared statements.

Synopsis

DeallocateStmt ::=
    DeallocateSym 'PREPARE' Identifier

DeallocateSym ::=
    'DEALLOCATE'
|   'DROP'

Identifier ::=
    identifier
|   UnReservedKeyword
|   NotKeywordToken
|   TiDBKeyword

Examples

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 compatibility

This statement is understood to be fully compatible with MySQL. Any compatibility differences should be reported via an issue on GitHub.

See also

• PREPARE
• EXECUTE