向表中插入数据的时候,自动删除重复的数据

create table EE ( ID int identity(1,1) primary key, bh int, rq datetime, sj varchar(20) ) insert into EE select 1,'2009-09-09','09:01' insert into EE select 1,'2009-09-09','09:02' create trigger tg_Del on EE for insert as --如果表中存在的话 if exists(select * from EE join inserted i on EE.bh=i.bh and EE.rq=i.rq and EE.sj=i.sj) --删除刚刚插入的信息 delete E1 from EE E1,inserted i where E1.bh=i.bh and E1.rq=i.rq and E1.sj=i.sj and i.ID>E1.ID --测试数据 insert into EE(bh,rq,sj) select 1,'2009-09-09','09:02' select * from EE ID bh rq sj ----------- ----------- ----------------------- -------------------- 1 1 2009-09-09 00:00:00.000 09:01 3 1 2009-09-09 00:00:00.000 09:02 insert into EE(bh,rq,sj) select 1,'2009-09-09','09:03' select * from EE ID bh rq sj ----------- ----------- ----------------------- -------------------- 1 1 2009-09-09 00:00:00.000 09:01 3 1 2009-09-09 00:00:00.000 09:02 4 1 2009-09-09 00:00:00.000 09:03