MySQL 练习题16.1

Posted 2022-01-07 Aoian51CTO

mysql 练习题16.1

1…创建存储过程，使用流程控制语句，编写SQL语句，要求以下：
（1）实现1-10之间数字的遍历。
（2）当数字大于10退出遍历。
（3）数字在1-10之间时，遍历数字并输出。

mysql> delimiter //
mysql> create procedure proc10()
    -> begin
    -> declare id int default 0;
    -> my_loop:loop
    -> set id=id+1;
    -> if id>10 then leave my_loop;
    -> end if;
    -> select id;
    -> end loop my_loop;
    -> end //

mysql> create procedure proc10()
    -> begin
    -> declare i int default 1;
    -> while i<=10 do
    -> select i;
    -> set i=i+1;
    -> end while;
    -> end //
Query OK, 0 rows affected (0.00 sec)

2…创建的学生表及数据，创建存储过程，定义两个变量，分别接收tom的成绩和性别，输出这两个变量，调用并删除存储过程

mysql> select * from student;
+----+------+-------+--------+
| id | name | grade | gender |
+----+------+-------+--------+
|  1 | tom  |    60 | 男     |
|  2 | jack |    70 | 男     |
|  3 | rose |    90 | 女     |
|  4 | lucy |   100 | 女     |
+----+------+-------+--------+
4 rows in set (0.00 sec)

mysql> delimiter //
mysql> create procedure proc10()
    -> begin
    -> declare s_grade float;
    -> declare s_gender char(4);
    -> select grade,gender into s_grade,s_gender from student where name=tom;
    -> select s_grade,s_gender;
    -> end //
Query OK, 0 rows affected (0.00 sec)

mysql> call proc10() //
+---------+----------+
| s_grade | s_gender |
+---------+----------+
|      60 | 男       |
+---------+----------+
1 row in set (0.02 sec)

Query OK, 0 rows affected (0.02 sec)