MySQL---储存过程

创建存储过程

调用存储过程

# 创建无参数的储存过程
mysql> CREATE PROCEDURE sp1() SELECT VERSION();

# 调用无参数的储存过程可以不加括号
mysql> CALL sp1;
mysql> CALL sp1();
+------------+
| VERSION()  |
+------------+
| 5.7.18-log |
+------------+

# 创建IN类型参数
mysql> CREATE PROCEDURE removeUserById(IN p_id INT UNSIGNED)
-> BEGIN
-> DELETE FROM user WHERE id = p_id ;
-> END
-> //

mysql> CALL removeUserById(9)//

删除储存过程

示例

// 删除指定的记录，并返回剩余记录的数量
mysql> CREATE PROCEDURE removeUserAndReturnUserNums(IN p_id INT UNSIGNED,OUT userNums INT UNSIGNED)
-> BEGIN
-> DELETE FROM user WHERE id = p_id;
-> SELECT COUNT(id) FROM user INTO userNums;
-> END
-> //
Query OK, 0 rows affected (0.00 sec)

# 使用ROW_COUNT() 获得被更改的行数
mysql> DELIMITER //
mysql> CREATE PROCEDURE removeUserByUserName(IN user_name VARCHAR(20),OUT deleteCount INT,OUT restCount INT)
-> BEGIN
-> DELETE FROM user WHERE username = user_name;
-> SELECT ROW_COUNT() INTO deleteCount;
-> SELECT COUNT(id) FROM user INTO restCount;
-> END
-> //

mysql> SELECT @a,@b;
+------+------+
| @a   | @b   |
+------+------+
|    3 |    4 |
+------+------+