SQL语句NOT EXISTS实现除法运算

create procedure findall
as
begin
   declare @i int,
   declare @j int,
   declare @id2count int,
   declare @sidcount int,
   declare @sidtable table(id int identity(1,1),sid int),
   declare @id2coursetable table(id int identity(1,1),cid int),
   declare @result int
   declare @sidtmp int
   declare @cidtmp int    
   
   select @sidcount = count(sid) from grade group by sid
   select @id2count = count(*) from grade where sid=2
   insert into @sidtable(sid) select sid from grade group by sid
   insert into @id2coursetable(cid) select cid from grade where sid =2
   set @i=1
   set @j=1
   set @result=1
   
   while @i < @sidcount
   begin
       select @sidtmp = sid from @sidtable where id=@i
       while @j<@id2count
       begin
           select @cidtmp = cid from @id2coursetable where id=@j
           select @result=count(*) from grade where sid = @sidtmp and cid = @cidtmp
           if(@result = 0)
           begin
               break
           end
       end
       if(@result = 1)
       begin
          print @sidtmp
       end
   end
end

select sid from grade as grade1 where sid <> 2 and not exists 
         (select * from grade as grade2 where grade2.sid =2 and not exists
                  (select * from grade as grade3 where grade3.sid = grade1.sid and grade3.cid = grade2.cid)
         ) group by sid