UFN_COMMUNICATION_LETTEREXISTS

create function dbo.UFN_COMMUNICATION_LETTEREXISTS
(
    @SEGMENTATIONID uniqueidentifier,
    @COMMUNICATIONLETTERID uniqueidentifier
)
returns bit
as begin    
    declare @RET bit;

    select 
        @RET = case 
                    when exists(
                        select ID 
                        from dbo.COMMUNICATIONLETTER
                        where SEGMENTATIONID = @SEGMENTATIONID
                            and ID = @COMMUNICATIONLETTERID)
                        then 1 
                    else 0 
                end;

    return @RET;
end