fnGetClientSiteUsage_Filtered

CREATE FUNCTION [dbo].[fnGetClientSiteUsage_Filtered]
(
      @ID int,
      @FilterBy int
)
RETURNS 
@RESULTS TABLE 
(
      ClientSitesID int
)
AS
BEGIN
      /*
            @FilterBy:
                  1 = LayoutID
                  2 = TemplateID
                  3 = PageID
                  4 = ContentID
      */
      if @FilterBy = 1 --LayoutID
      begin
            insert into @RESULTS
            select distinct ClientSitesID 
            from vwSitePages
            where templatelayoutid=@id or layoutid=@id
      end
      else if @FilterBy = 2 --TemplateID
      begin
            insert into @RESULTS
            select distinct ClientSitesID 
            from vwSitePages
            where TemplatePageID=@ID or id=@ID
      end
      else if @FilterBy = 3 --PageID
      begin
            insert into @RESULTS
            select distinct ClientSitesID 
            from vwSitePages
            where ID=@ID      
      end
      else if @FilterBy = 4 --ContentID
      begin
            insert into @RESULTS
            select distinct vsp.ClientSitesID 
            from vwSitePages vsp
            inner join vwPageContent vpc on vpc.PageID=vsp.ID and vpc.ID=@ID
      end
      RETURN 
END