关于触发器递归死循环的有关问题

关于触发器递归死循环的问题
CREATE TRIGGER delfiled on tablename1 FOR DELETE 
AS
declare @id int,@ename varchar(50),@strdrop varchar(200)

select @id=id from deleted

select @ename=ename from deleted

delete from tablename1 where fatherid=@id

set @strdrop='alter table tablename2 drop column '+@ename+''

exec (@strdrop)

这个触发器产生了死循环，怎样修改才能避免此循环，谢谢

[解决办法]

SQL code

CREATE TRIGGER delfiled  on tablename1 FOR  DELETE  AS IF @@ROWCOUNT = 0    RETURNdeclare @id int,@ename varchar(50),@strdrop varchar(200) select @id=id from deleted select @ename=ename from deleted delete from tablename1 where fatherid=@id set @strdrop= 'alter table tablename2  drop column   '+@ename+ ' ' exec (@strdrop)