触发器和存储过程

1.触发器建立两个表:goods(商品表)、orders(订单表)use mydb16_trigger; create table goods( gid char(8) primary key, #商品编号 name varchar(10), #商品名 price decimal(8,2), #价格 num int); #数量 create table orders( oid int primary key auto_increment, #订单号 gid char(10) not null, #商品号 name varchar(10), #商品名 price decimal(8,2), #价格 onum int, #订单数量 otime date); #订单时间在商品表中导入商品记录insert into goods values (A0001,橡皮,2.5,100), (B0001,小楷本,2.8,210), (C0001,铅笔,1.2,120), (D0001,计算机,28,20);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create trigger orders_after_insert_trigger after insert on orders for each row update goods set numnum-new.onum where gidnew.gid; select * from goods; select * from orders; insert into orders values(null,C0001,铅笔,1.2,20,now()); select * from goods; select * from orders;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create trigger orders_after_delete_trigger after delete on orders for each row update goods set numnumold.onum where gidold.gid; select * from goods; select * from orders; delete from orders where oid1; select * from orders; select * from goods;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insert into orders values(null,A0001,橡皮,2.5,20,now()); create trigger orders_after_update_trigger after update on orders for each row update goods set numnum(old.onum-new.onum) where gidnew.gid; select * from goods; select * from orders; update orders set onum5 where oid2; select * from orders; select * from goods;2.存储过程使用mydb7_openlab库use mydb7_openlab; select database();创建提取emp_new表所有员工姓名和工资的存储过程s1select * from emp_new; delimiter // create procedure s1() begin select name 员工姓名,incoming 工资 from emp_new; end // delimiter ; call s1();创建存储过程s2实现输入员工姓名后返回员工的年龄select * from emp; delimiter // desc emp// create procedure s2(in p_ename varchar(20),out p_age int) begin select year(now())-year(hiredate) into p_age from emp where enamep_ename; end // delimiter ; call s2(WARD,age); select age 年龄;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select * from emp_new; desc emp_new; delimiter // create procedure s3(in p_dept int,out p_avgincoming decimal(8,2)) begin select avg(incoming) into p_avgincoming from emp_new where dept2p_dept; end // delimiter ; call s3(101,avg_incoming); select avg_incoming 平均工资;