根据图片内容完成作业

1.建表

（1）建立两个表:goods(商品表)、orders(订单表)

mysql> create table goods(
    -> gid char(8) primary key,
    -> name varchar(10),
    -> price decimal(8,2),
    -> num int);

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); 

 （2）在商品表中导入商品记录

mysql> insert into goods values
    -> ('A0001','橡皮',2.5,100),
    -> ('B0001','小楷本',2.8,210),
    -> ('C0001','铅笔',1.2,120),
    -> ('D0001','计算器',28,20);

2.建立触发器

（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> create trigger order_after_insert_trigger
    -> after insert on orders for each row
    -> update goods set num=goods.num-new.onum where gid=new.gid;

（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 order_after_delete_trigger
    -> after delete on orders for each row
    -> update goods set num=num+old.onum where gid=old.gid; 

 （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 order_after_update_trigger
    -> after update on orders for each row
    -> update goods set num=num+(old.onum-new.onum) where gid=old.gid;

 3.存储过程

（1）使用mydb7 openlab，创建提取emp_new表所有员工姓名和工资的存储过程proc01

mysql> delimiter //
mysql> create procedure proc01()
    -> begin
    ->          select name,incoming from emp_new;
    -> end //

mysql> delimiter ;
mysql> call proc01();

 （2）创建存储过程proc02，实现输入员工姓名后返回员工的年龄

mysql> delimiter //
mysql> create procedure proc02(in in_name varchar(10), out out_age int)
    -> begin
    ->          select age into out_age from emp_new where name=in_name;
    -> end //

mysql> delimiter ;
mysql> call proc02('张三',@out_age);

mysql> select @out_age;

 （3）创建一个存储过程proc03，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 proc03(in in_dept2 int, out out_avg float)
    -> begin
    ->          select avg(incoming) into out_avg from emp_new where in_dept2=dept2;
    -> end //

mysql> delimiter ;
mysql> call proc03(101,@out_avg);

mysql> select @out_avg;