if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[purchase]') and OBJECTPROPERTY(id, N'IsTable') = 1)
drop table [dbo].[purchase]
GOcreate table purchase(
编号 int identity(11001,1) not null,
名称 nvarchar (255),
单价 money ,
编号reverse int,
primary key(编号)
)如何实现呢?
drop table [dbo].[purchase]
GOcreate table purchase(
编号 int identity(11001,1) not null,
名称 nvarchar (255),
单价 money ,
编号reverse int,
primary key(编号)
)如何实现呢?
编号 int identity(11001,1) not null,
名称 nvarchar (255),
单价 money ,
编号reverse as -编号,
primary key(编号)
) insert purchase select 'a',0.5
select * from purchase
/*
编号 名称 单价 编号reverse
11001 a 0.50 -11001
*/
编号 int identity(11001,1) not null,
名称 nvarchar (255),
单价 money ,
编号reverse int,
primary key(编号)
)
goCREATE TRIGGER my_trig ON tb FOR INSERT
as
update tb set 编号reverse = 0 - (select 编号 from inserted) where 编号 = (select 编号 from inserted)
goinsert into tb (名称 , 单价) values('a' , 1)
insert into tb (名称 , 单价) values('b' , 2)select * from tbdrop table tb/*
编号 名称 单价 编号reverse
----------- --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --------------------- -----------
11001 a 1.0000 -11001
11002 b 2.0000 -11002(所影响的行数为 2 行)*/
编号 int identity(11001,1) not null,
名称 nvarchar (255),
单价 money ,
编号reverse as reverse(编号),
primary key(编号)
) insert purchase select 'a',0.5
select * from purchase
/*
编号 名称 单价 编号reverse
11001 a 0.50 10011
*/