How could your collegue get the results? It's an impossible query. If you have 2 records with the same ID (MAPREF) and the same date and your question is "give me the record with the greatest date" then the only answer is to return both or neither. returning just one is not necessraily the "greatest date" because they both have the exact same date. There has to be more criteria to return just one record if both your current criteria fields are equal.