MySQL存储过程的异常处理方法

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。