MySQL存储过程的异常处理方法

数据库  /  管理员 发布于 6年前   118

本文实例讲述了MySQL存储过程的异常处理方法。分享给大家供大家参考。具体如下：

mysql>mysql> delimiter $$mysql>mysql> CREATE PROCEDURE myProc  ->   (p_first_name     VARCHAR(30),  ->    p_last_name      VARCHAR(30),  ->    p_city        VARCHAR(30),  ->    p_description     VARCHAR(30),  ->    OUT p_sqlcode     INT,  ->    OUT p_status_message VARCHAR(100))  -> BEGIN  ->  -> /* START Declare Conditions */  ->  ->  DECLARE duplicate_key CONDITION FOR 1062;  ->  DECLARE foreign_key_violated CONDITION FOR 1216;  ->  -> /* END Declare Conditions */  ->  -> /* START Declare variables and cursors */  ->  ->   DECLARE l_manager_id    INT;  ->  ->   DECLARE csr_mgr_id CURSOR FOR  ->    SELECT id  ->     FROM employee  ->    WHERE first_name=p_first_name  ->       AND last_name=p_last_name;  ->  -> /* END Declare variables and cursors */  ->  -> /* START Declare Exception Handlers */  ->  ->  DECLARE CONTINUE HANDLER FOR duplicate_key  ->   BEGIN  ->    SET p_sqlcode=1052;  ->    SET p_status_message='Duplicate key error';  ->   END;  ->  ->  DECLARE CONTINUE HANDLER FOR foreign_key_violated  ->   BEGIN  ->    SET p_sqlcode=1216;  ->    SET p_status_message='Foreign key violated';  ->   END;  ->  ->  DECLARE CONTINUE HANDLER FOR not FOUND  ->   BEGIN  ->    SET p_sqlcode=1329;  ->    SET p_status_message='No record found';  ->   END;  ->  -> /* END Declare Exception Handlers */  ->  -> /* START Execution */  ->  ->  SET p_sqlcode=0;  ->  OPEN csr_mgr_id;  ->  FETCH csr_mgr_id INTO l_manager_id;  ->  ->  IF p_sqlcode<>0 THEN      /* Failed to get manager id*/  ->   SET p_status_message=CONCAT(p_status_message,' when fetching manager id');  ->  ELSE  ->   INSERT INTO employee (first_name,id,city)  ->   VALUES(p_first_name,l_manager_id,p_city);  ->  ->   IF p_sqlcode<>0 THEN   /* Failed to insert new department */  ->    SET p_status_message=CONCAT(p_status_message,  ->  ' when inserting new department');  ->   END IF;  ->  END IF;  ->  ->  CLOSE csr_mgr_id;  ->  -> /* END Execution */  ->  -> END$$Query OK, 0 rows affected (0.02 sec)mysql>mysql> delimiter ;mysql> set @myCode = 0;Query OK, 0 rows affected (0.00 sec)mysql> set @myMessage = 0;Query OK, 0 rows affected (0.00 sec)mysql>mysql> call myProc('Jason','Martin','New City','New Description',@myCode,@myMessage);Query OK, 1 row affected (0.00 sec)mysql>mysql> select @myCode, @myMessage;+---------+------------+| @myCode | @myMessage |+---------+------------+| 0    | NULL    |+---------+------------+1 row in set (0.00 sec)mysql>mysql> drop procedure myProc;Query OK, 0 rows affected (0.00 sec)

希望本文所述对大家的MySQL数据库程序设计有所帮助。