MERGE INTO TABLENAME WITH (HOLDLOCK) AS target
            USING
            (SELECT :id AS id, :lastaccess AS lastaccess ) AS SOURCE
            (id,lastaccess)
            ON
            (target.id = SOURCE.id)
            WHEN MATCHED THEN UPDATE SET lastaccess = :lastaccess2
            WHEN NOT MATCHED THEN INSERT (id, lastaccess)
            VALUES (:id2, :lastaccess3);