cr一:创建goods表和orders表;
mysql> use mydb16_tirgeer
Database changed
mysql> create table goods(
-> gid char(8) primary key,
-> name varchar(10),
-> price decimal(8,2),
->
-> num int);
Query OK, 0 rows affected (0.03 sec)
```powershell
mysql> create table orders(
-> oid int primary key auto_increment,
-> gid char(10) not null,
-> name varchar(10),
-> price decimal(8,2),
-> onum int,
-> otime date);
Query OK, 0 rows affected (0.01 sec)
二:导入商品记录;
```powershell
mysql> insert into goods values('A0001','橡皮',2.5,100),('B0001','小谐本',2.8,210);
Query OK, 2 rows affected (0.01 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> insert into goods values('C0001','铅笔',1.2,120),('D0001','计算器',28,20);
Query OK, 2 rows affected (0.00 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from goods;
+-------+--------+-------+------+
| gid | name | price | num |
+-------+--------+-------+------+
| A0001 | 橡皮 | 2.50 | 100 |
| B0001 | 小谐本 | 2.80 | 210 |
| C0001 | 铅笔 | 1.20 | 120 |
| D0001 | 计算器 | 28.00 | 20 |
+-------+--------+-------+------+
4 rows in set (0.00 sec)
三:
mysql> create trigger orders_after_insert_trigger
-> after insert on orders for each row
-> update goods set num=num-new.onum
-> where gid=new.gid;
Query OK, 0 rows affected (0.01 sec)
mysql> insert into orders (gid,name,price,onum,otime) value('C0001','铅笔',1.2,80,now());
Query OK, 1 row affected, 1 warning (0.01 sec)
mysql> select * from goods;
+-------+--------+-------+------+
| gid | name | price | num |
+-------+--------+-------+------+
| A0001 | 橡皮 | 2.50 | 100 |
| B0001 | 小谐本 | 2.80 | 210 |
| C0001 | 铅笔 | 1.20 | 40 |
| D0001 | 计算器 | 28.00 | 20 |
+-------+--------+-------+------+
4 rows in set (0.00 sec)
mysql> select * from orders;
+-----+-------+------+-------+------+------------+
| oid | gid | name | price | onum | otime |
+-----+-------+------+-------+------+------------+
| 1 | C0001 | 铅笔 | 1.20 | 80 | 2024-07-26 |
+-----+-------+------+-------+------+------------+
1 row in set (0.00 sec)
2.
mysql> create trigger orders_after_delete_trigger
-> after delete on orders for each row
-> update goods set num=num+old.onum
-> where gid = old.gid;
Query OK, 0 rows affected (0.00 sec)
mysql> delete From orders where gid='C0001';
Query OK, 1 row affected (0.00 sec)
mysql> select * from goods;
+-------+--------+-------+------+
| gid | name | price | num |
+-------+--------+-------+------+
| A0001 | 橡皮 | 2.50 | 100 |
| B0001 | 小谐本 | 2.80 | 210 |
| C0001 | 铅笔 | 1.20 | 120 |
| D0001 | 计算器 | 28.00 | 20 |
+-------+--------+-------+------+
4 rows in set (0.00 sec)
mysql> select * from orders;
Empty set (0.00 sec)
3.
mysql> create trigger orders_after_update_trigger
-> after update on orders for each row
-> update goods set num=num+(old.onum-new.onum)
-> where gid=old.gid;
Query OK, 0 rows affected (0.01 sec)
mysql> insert into orders (gid,name,price,onum,otime) value('C0001','铅笔',1.2,80,now());
Query OK, 1 row affected, 1 warning (0.00 sec)
mysql> select * from orders;
+-----+-------+------+-------+------+------------+
| oid | gid | name | price | onum | otime |
+-----+-------+------+-------+------+------------+
| 2 | C0001 | 铅笔 | 1.20 | 80 | 2024-07-26 |
+-----+-------+------+-------+------+------------+
1 row in set (0.00 sec)
mysql> select * from goods;
+-------+--------+-------+------+
| gid | name | price | num |
+-------+--------+-------+------+
| A0001 | 橡皮 | 2.50 | 100 |
| B0001 | 小谐本 | 2.80 | 210 |
| C0001 | 铅笔 | 1.20 | 40 |
| D0001 | 计算器 | 28.00 | 20 |
+-------+--------+-------+------+
4 rows in set (0.00 sec)
mysql> update orders set onum=35 where gid = 'C0001';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from orders;
+-----+-------+------+-------+------+------------+
| oid | gid | name | price | onum | otime |
+-----+-------+------+-------+------+------------+
| 2 | C0001 | 铅笔 | 1.20 | 35 | 2024-07-26 |
+-----+-------+------+-------+------+------------+
1 row in set (0.00 sec)
mysql> select * from goods;
+-------+--------+-------+------+
| gid | name | price | num |
+-------+--------+-------+------+
| A0001 | 橡皮 | 2.50 | 100 |
| B0001 | 小谐本 | 2.80 | 210 |
| C0001 | 铅笔 | 1.20 | 85 |
| D0001 | 计算器 | 28.00 | 20 |
+-------+--------+-------+------+
4 rows in set (0.00 sec)
mysql> use mydb7_openlab;
Database changed
mysql> show tables;
+-------------------------+
| Tables_in_mydb7_openlab |
+-------------------------+
| dept |
| emp |
| emp_new |
| user |
+-------------------------+
4 rows in set (0.00 sec)
delimiter //
mysql> create procedure s1()
-> begin
-> select name,incoming from emp_new;
-> end //
Query OK, 0 rows affected (0.01 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 (0.00 sec)
Query OK, 0 rows affected (0.02 sec)
mysql>
mysql> create procedure s2(in_name varchar(11),out out_age int)
-> begin
-> select age into out_age from emp_new where name=in_name;
-> end //
Query OK, 0 rows affected (0.00 sec)
mysql> call s2('王五',@age);
-> //
Query OK, 1 row affected (0.00 sec)
mysql> delimiter ;
mysql> select @age;
+------+
| @age |
+------+
| 24 |
+------+
1 row in set (0.00 sec)
mysql> create procedure s3(in in_dept int , out avg_sal float)
-> begin
-> select avg(incoming) into avg_sal from emp_new where dept2=in_dept;
-> end //
Query OK, 0 rows affected (0.00 sec)
mysql> call s3(101,@avg_sal)//
Query OK, 1 row affected (0.00 sec)
mysql> delimiter ;
mysql> select @avg_sal;
+-------------------+
| @avg_sal |
+-------------------+
| 3166.666748046875 |
+-------------------+
1 row in set (0.00 sec)