本文實例講述了MySQL存儲過程的異常處理方法。。具體如下：
| 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) |
希望本文所述對大家的MySQL數據庫程序設計有所幫助。
新聞熱點
疑難解答
