将列的值存储到 MySQL 存储过程的变量中
mysqlmysqli database更新于 2023/10/24 9:00:00
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 -> ); Query OK, 0 rows affected (0.49 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable2034(StudentName,StudentAge) values('Chris',23);
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable2034(StudentName,StudentAge) values('David',21);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable2034(StudentName,StudentAge) values('Robert',25);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable2034(StudentName,StudentAge) values('Mike',19);
Query OK, 1 row affected (0.14 sec)
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)
以下查询用于创建存储过程并将上表的列值存储在存储过程变量中 −
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
-> //
Query OK, 0 rows affected (0.09 sec)
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)
Query OK, 0 rows affected (0.06 sec)
