我有一张表树形表（TreeGrid），字段是 id parent ishaveleaf（是否含有叶子节点）
当这张表发生变化的时候，我就检查是否含有叶子节点，如果含有就更新ishaveleaf的值为1否则为0

请问这样的触发器怎么写？ 

我用的是sqlserver2005

CREATE TRIGGER TIG1 ON TREEGRID
AS
BEGIN
UPDATE T1
SET T1.ISHAVLEAF=CASE WHEN EXISTS(
SELECT 1 FROM TREEGRID T2 WHERE T2.PARENTID=T1.ID
) THEN 1 ELSE 0 END
FROM TREEGRID T1
INNER JOIN INSERTED T2 ON T1.ID=T2.ID OR T1.ID=T2.PARENTID
END

------解决方案--------------------
看错了 可以写
SQL code
create table csdn(id int identity, parent int ,ishaveleaf int)
insert csdn(parent,ishaveleaf)  
select 1,0 
union all select 4,0
select * from csdn

alter trigger ins_csdn
 on csdn
 for insert 
as 
begin
   if exists(select * from csdn a,inserted b where a.id=b.id and a.ishaveleaf=1 )
   return
   else
   update csdn set ishaveleaf=1 from  csdn a,inserted b where a.id=b.parent
end