要声明变量,请在MySQL存储过程中使用DECLARE。让我们首先创建一个表-
mysql> create table DemoTable2034 -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(20), -> StudentAge int -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable2034(StudentName,StudentAge) values('Chris',23); mysql> insert into DemoTable2034(StudentName,StudentAge) values('David',21); mysql> insert into DemoTable2034(StudentName,StudentAge) values('Robert',25); mysql> insert into DemoTable2034(StudentName,StudentAge) values('Mike',19);
使用select语句显示表中的所有记录-
mysql> select *from DemoTable2034;
这将产生以下输出-
+-----------+-------------+------------+ | StudentId | StudentName | StudentAge | +-----------+-------------+------------+ | 1 | Chris | 23 | | 2 | David | 21 | | 3 | Robert | 25 | | 4 | Mike | 19 | +-----------+-------------+------------+ 4 rows in set (0.00 sec)
这是创建存储过程并将上述表的列值存储在存储过程变量中的查询-
mysql> delimiter // mysql> create procedure select_into_variable(id int) -> begin -> declare name varchar(50); -> select StudentName into name from DemoTable2034 where StudentId=id; -> select concat('Your Name is= ',name); -> end -> // mysql> delimiter ;
调用存储过程-
mysql> call select_into_variable(4);
这将产生以下输出-
+-------------------------------+ | concat('Your Name is= ',name) | +-------------------------------+ | Your Name is= Mike | +-------------------------------+ 1 row in set (0.04 sec)