I know this is a long shot without seeing something, but I figured, what the heck. I am merging data from an old database to a new database. The structure is a little different.So, anything with an _ prefix is from the old DB and anything from the new DB has no prefix. So, the subselect is returning more than one row. I for the life of me cannot figure out why. A registration typically has only one account and race per line. So, I can't figure out why the sub is returning more than 1 row. Any thoughts?SELECT (SELECT Registration.[Guid] FROM Registration WHERE RaceGuid = r.Guid AND AccountGuid = a.Guid AND Registration.isPaid = 1),r.Guid as RaceGuid,evt.Guid as EventGuid,ath.Guid as AthleteGuid,c2.CodeName,c3.CodeName,ur.IsPaid,ur.IsPaid,CASE WHEN u.USATNUMBER LIKE '%[^-+ 0-9]%' THEN 0 ELSE NULL END,ur.IsPaidFROM _UserRaceFee urfINNER JOIN _Events e ON e.RaceID = urf.RaceIDINNER JOIN _Users u ON u.UserID = urf.UserIDINNER JOIN Account a ON a.UserID = u.UserIDINNER JOIN Race r ON r.RaceID = urf.RaceIDINNER JOIN _Codes c ON c.CodeID = urf.FeeID INNER JOIN [Event] evt ON evt.EventID = urf.FeeID AND evt.RaceGuid = r.GuidINNER JOIN _Profiles p ON p.ProfileID = urf.ProfileIDINNER JOIN Athlete ath ON ath.ProfileID = p.ProfileIDINNER JOIN _UserRace ur ON ur.ProfileID = urf.ProfileID AND ur.UserID = urf.UserID AND urf.RaceID = ur.RaceIDINNER JOIN _Codes c2 ON c2.CodeID = ur.TShirtSizeINNER JOIN _Codes c3 ON c3.CodeID = ur.DivisionWHERE urf.RaceID = 146