UFN_CONSTITUENTDATAREVIEWROLLBACK_UNIQUEROLLBACK

create function dbo.UFN_CONSTITUENTDATAREVIEWROLLBACK_UNIQUEROLLBACK(
    @ID uniqueidentifier
)
returns bit
with execute as caller
as begin
    declare @NULLID uniqueidentifier;
    set @NULLID = 'B884DE97-1AC1-43DD-B011-1B28CFD30F5E';

    declare @VALID bit;

    select @VALID = case count(*) when 1 then 1 else 0 end
    from dbo.CONSTITUENTDATAREVIEWROLLBACK [CK]
    inner join dbo.CONSTITUENTDATAREVIEWROLLBACK [MATCH] on
        [MATCH].CONTEXTRECORDID = [CK].CONTEXTRECORDID and
        isnull([MATCH].ROLLBACKAUDITID,@NULLID) = isnull([CK].ROLLBACKAUDITID,@NULLID) and
        ([CK].ROLLBACKAUDITID is null or
         isnull([MATCH].SOURCEAUDITID,@NULLID) = isnull([CK].SOURCEAUDITID,@NULLID))
    where [CK].ID = @ID;

    return @VALID;
end