请问高手，大于0时必需唯一的约束怎么写？
------解决方案--------------------
create function dbo.funtest(@colname int)
returns int
as
declare @i int
if @colname > 0
select @i = count(*) from tb where [email protected]
else
set @i=1
return @i
alter table dbo.tablename add
constraint chenkname check (dbo.funtest(colname)=1)