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MYSQL触发器和存储过程习题

news 2025/11/12 18:41:21

1.1 建立触发器，订单表中增加订单数量后，商品表商品数量同步减少对应的商品订单出数量,并测试

mysql> delimiter //
mysql> create trigger trg_orders_insert-> after insert on orders for each row-> begin->       update goods->       set num=num-new.onum->       where gid=new.gid;-> end //

1.2 建立触发器，实现功能:客户取消订单，恢复商品表对应商品的数量

mysql> create trigger trg_orders_delete-> after delete on orders for each row-> begin->       update goods->       set num=num+old.onum->       where gid=old.gid;-> end //

1.3 建立触发器，实现功能:客户修改订单，商品表对应商品数量同步更新

mysql> create trigger trg_orders_update-> after update on orders for each row-> begin->       update goods->       set num=num+old.onum-new.onum->       where gid=new.gid;-> end //
Query OK, 0 rows affected (0.01 sec)

测试触发器

新增订单

mysql> insert into orders(gid,name,price,onum,otime) values('A0001','橡皮',2.5,5,curdate());
Query OK, 1 row affected (0.01 sec)mysql> select * from orders;
+-----+-------+--------+-------+------+------------+
| oid | gid   | name   | price | onum | otime      |
+-----+-------+--------+-------+------+------------+
|   1 | A0001 | 橡皮   |  2.50 |    5 | 2025-11-11 |
+-----+-------+--------+-------+------+------------+
1 row in set (0.00 sec)mysql> select * from goods;
+-------+-----------+-------+------+
| gid   | name      | price | num  |
+-------+-----------+-------+------+
| A0001 | 橡皮      |  2.50 |   95 |
| B0001 | 小楷本    |  2.80 |  210 |
| C0001 | 铅笔      |  1.20 |  120 |
| D0001 | 计算机    | 28.00 |   20 |
+-------+-----------+-------+------+
4 rows in set (0.00 sec)

删除订单

mysql> delete from orders where oid=1;
Query OK, 1 row affected (0.00 sec)mysql> select * from orders;
Empty set (0.00 sec)mysql> select * from goods;
+-------+-----------+-------+------+
| gid   | name      | price | num  |
+-------+-----------+-------+------+
| A0001 | 橡皮      |  2.50 |  100 |
| B0001 | 小楷本    |  2.80 |  210 |
| C0001 | 铅笔      |  1.20 |  120 |
| D0001 | 计算机    | 28.00 |   20 |
+-------+-----------+-------+------+
4 rows in set (0.01 sec)

修改订单

mysql> update orders set onum=10 where oid=1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0mysql> select * from goods;
+-------+-----------+-------+------+
| gid   | name      | price | num  |
+-------+-----------+-------+------+
| A0001 | 橡皮      |  2.50 |   90 |
| B0001 | 小楷本    |  2.80 |  210 |
| C0001 | 铅笔      |  1.20 |  120 |
| D0001 | 计算机    | 28.00 |   20 |
+-------+-----------+-------+------+
4 rows in set (0.00 sec)mysql> select * from orders;
+-----+-------+--------+-------+------+------------+
| oid | gid   | name   | price | onum | otime      |
+-----+-------+--------+-------+------+------------+
|   1 | A0001 | 橡皮   |  2.50 |   10 | 2025-11-11 |
+-----+-------+--------+-------+------+------------+
1 row in set (0.00 sec)

2.1 使用mydb7 openlab库

mysql> use mydb7_openlab;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> show tables;
+-------------------------+
| Tables_in_mydb7_openlab |
+-------------------------+
| dept                    |
| emp_new                 |
+-------------------------+
2 rows in set (0.00 sec)

2.2 创建提取emp_new表所有员工姓名和工资的存储过程s

mysql> select * from dept;
+-------+-----------+
| dept1 | dept_name |
+-------+-----------+
|   101 | 财务      |
|   102 | 销售      |
|   103 | 运维      |
|   104 | 行政      |
+-------+-----------+
4 rows in set (0.00 sec)mysql> select * from emp_new;
+------+--------+------+----------------+----------+-------+
| sid  | name   | age  | worktime_start | incoming | dept2 |
+------+--------+------+----------------+----------+-------+
| 1789 | 张三   |   35 | 1980-01-01     |     4000 |   101 |
| 1674 | 李四   |   32 | 1983-04-01     |     3500 |   101 |
| 1776 | 王五   |   24 | 1990-07-01     |     2000 |   101 |
| 1568 | 赵六   |   57 | 1970-10-11     |     7500 |   102 |
| 1564 | 荣七   |   64 | 1963-10-11     |     8500 |   102 |
| 1879 | 牛八   |   55 | 1971-10-20     |     7300 |   103 |
+------+--------+------+----------------+----------+-------+
6 rows in set (0.00 sec)mysql> delimiter //
mysql> create procedure s1()-> begin->       select name,incoming from emp_new;-> end //
Query OK, 0 rows affected (0.04 sec)mysql> delimiter ;
mysql> call s1();
+--------+----------+
| name   | incoming |
+--------+----------+
| 张三   |     4000 |
| 李四   |     3500 |
| 王五   |     2000 |
| 赵六   |     7500 |
| 荣七   |     8500 |
| 牛八   |     7300 |
+--------+----------+
6 rows in set (0.01 sec)

2.3 创建存储过程s2，实现输入员工姓名后返回员工的年龄

mysql> delimiter //
mysql> create procedure s2(in emp_name varchar(10),out emp_age int)-> begin->       select age into emp_age from emp_new where name=emp_name;-> end //
Query OK, 0 rows affected (0.00 sec)mysql> delimiter ;
mysql> set @age=0;
Query OK, 0 rows affected (0.00 sec)mysql> call s2('张三',@age);
Query OK, 1 row affected (0.00 sec)mysql> select @age;
+------+
| @age |
+------+
|   35 |
+------+
1 row in set (0.00 sec)

2.4 创建一个存储过程s3，有2个参数，传入部门号，返回该部门的平均工资

mysql> delimiter //
mysql> create procedure s3(in dept_id int,out avg_incoming decimal(8,2))-> begin->       select avg(incoming) into avg_incoming from emp_new where dept2=dept_id;-> end //
Query OK, 0 rows affected (0.01 sec)mysql> delimiter ;
mysql> set @avg=0;
Query OK, 0 rows affected (0.00 sec)mysql> call s3(101,@avg);
Query OK, 1 row affected, 1 warning (0.00 sec)mysql> select @avg;
+---------+
| @avg    |
+---------+
| 3166.67 |
+---------+
1 row in set (0.00 sec)

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