如何创建带有 INOUT 参数的 MySQL 存储过程?
以下示例将演示 MySQL 存储过程与 INOUT 参数 −
mysql> DELIMITER // ; mysql> Create PROCEDURE counter(INOUT count INT, IN increment INT) -> BEGIN -> SET count = count + increment; -> END // Query OK, 0 rows affected (0.03 sec)
此处,‘count’是 INOUT 参数,它可以存储和返回值,而‘increment’是 IN 参数,它接受用户输入的值。
mysql> DELIMITER ; mysql> SET @counter = 0; Query OK, 0 rows affected (0.00 sec) mysql> CALL counter(@Counter, 1); Query OK, 0 rows affected (0.00 sec) mysql> Select @Counter; +----------+ | @Counter | +----------+ | 1 | +----------+ 1 row in set (0.00 sec) mysql> CALL counter(@Counter, 5); Query OK, 0 rows affected (0.00 sec) mysql> Select @Counter; +----------+ | @Counter | +----------+ | 6 | +----------+ 1 row in set (0.00 sec)
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