select b.fileno
from a,b
where charindex(a.grup,Priv)>0 and a.UserID=1

------解决方案--------------------
SQL code
declare @表A table(userid int,grup varchar(10))
insert into @表A select 1,2
insert into @表A select 1,4
insert into @表A select 2,3


declare @表B table(FileNo varchar(10),Priv varchar(10))
insert into @表B select '1001','1,2,5'
insert into @表B select '1002','2,3'
insert into @表B select '1003','3'

declare @userid int
set @userid=1
select fileno from @表A a,@表B b
where charindex(a.grup,b.priv)>0
and a.userid=@userid