Question

I have an Sql Query. It does not have any compilation error but in runtime it shows
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

 SELECT a.UserID FROM USERGROUPS a WHERE a.GroupID IN 
                      (CASE WHEN @group_id IS NULL THEN (select groupid from usergroups) ELSE 
                       CASE WHEN @group_id=0 THEN (select groupid from usergroups  where userid = @userid)ELSE
                      @group_id END END )

Thanks in advance.

Answer 1

Try this instead:

SELECT a.UserID 
  FROM USERGROUPS a 
  WHERE 
    (@groupid is NUll and a.GroupID IN   (select groupid from usergroups)) 
     or (@groupid = 0 and a.GroupID IN  (select groupid from usergroups  where (userid = @userid)))
      or a.GroupID IN  (@groupid)