触发器示例

题目:
表InGoods中的记录添加如下：
GoodsID    Shuliang
001           20.5
002            10
001            30

在添加的同时，自动触发更新累加另一表Goods中的NowSum字段值
GoodsID     NowSum
001           50.5
002           10

-----------------------------------------------------------------------------
create table InGoods
(
GoodsID varchar(10),
Shuliang numeric(10,1)
)
create table Goods
(
GoodsID varchar(10),
NowSum numeric(10,1)
)
insert Goods
select '001',0.0 union all
select '002',0.0
select * from Goods

go
create trigger trg_update
on Ingoods for insert
as
begin
update Goods
set NowSum=NowSum+(select Shuliang from inserted) where
Goods.GoodsID=(select GoodsID from inserted)
end
go

insert InGoods
select '001',20.5
select * from Goods
go
insert InGoods
select '002',10
select * from Goods
go
insert InGoods
select '001',30
select * from Goods
select * from Ingoods
drop trigger trg_update
drop table Goods,InGoods