如何创建存储过程以更新MySQL表中的值？
我们可以使用IN运算符创建一个存储过程来更新MySQL表中的值。为了理解它，我们以一个名为“student_info”的表为例，该表包含以下数据：
mysql> Select * from student_info; +------+---------+------------+------------+ | id | Name | Address | Subject | +------+---------+------------+------------+ | 101 | YashPal | Amritsar | History | | 105 | Gaurav | Jaipur | Literature | | 110 | Rahul | Chandigarh | History | | 125 | Raman | Bangalore | Computers | +------+---------+------------+------------+ 4 rows in set (0.01 sec)
现在，通过如下创建名为“update_studentinfo”的过程，我们可以更新“student_info”表中的值-
mysql> DELIMITER // ; mysql> Create Procedure Update_studentinfo ( IN p_id INT, IN p_address varchar(20)) -> BEGIN -> UPDATE student_info -> SET -> address = p_address WHERE id = p_id; -> END //
现在，使用我们要在表中更新的值调用该过程，如下所示：
mysql> Delimiter ; // mysql> CALL Update_studentinfo(125, 'Shimla'); mysql> Select * from student_info; +------+---------+------------+------------+ | id | Name | Address | Subject | +------+---------+------------+------------+ | 101 | YashPal | Amritsar | History | | 105 | Gaurav | Jaipur | Literature | | 110 | Rahul | Chandigarh | History | | 125 | Raman | Shimla | Computers | +------+---------+------------+------------+ 4 rows in set (0.00 sec)
上面的结果集表明，表中更新了ID=125的记录的地址。