求一个删除语句！
一、建表
CREATE TABLE [dbo].[Table_del](
[id] [int] IDENTITY(1,1) NOT NULL,
[tcode] [varchar](20) NULL,
[tyear] [varchar](20) NULL,
[tmon] [varchar](10) NULL,
[tmmemo] [varchar](10) NULL,
[tvalue] [numeric](18, 2) NULL
) ON [PRIMARY]

二、测试数据


insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1001','2012','12','a',0)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1001','2012','12','b',-1)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1001','2012','12','c',1)

insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1002','2012','12','a',0)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1002','2012','12','b',0)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1002','2012','12','c',0)

insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1003','2013','01','a'0)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1003','2013','01','b'2)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1003','2013','01','c'-1)

insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1004','2013','01','a'0)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1004','2013','01','b'0)
insert into Table_del(tcode, tyear,tmon,tmmemo,tvalue) values('1004','2013','01','c'0)

...............


三、求一个sql删除语句。（删除条件：tcode, tyear,tmon相同，三行的tvalue均为0.）


------解决方案--------------------

delete table_del where tcode in(

select tcode from table_del

where tvalue=0

group by tcode

having COUNT(1)=3)

------解决方案--------------------

delete table_del where exists(

select 1 from table_del as a

where a.tvalue=0 and table_del.tcode=a.tcode

and table_del.tyear=a.tyear and table_del.tmon=a.tmon

group by tcode,tyear,tmon

having COUNT(1)=3)