[Solved] 2 rows presented as 1

Just a wild guess:

SELECT *
FROM table AS S1
WHERE EXISTS 
      ( SELECT *
        FROM table AS S2
        WHERE ( S2.code = S1.code )
          AND (  ( S1.column1 IS NULL  AND  S2.column1 IS NOT NULL ) 
              OR ( S2.column1 IS NULL  AND  S1.column1 IS NOT NULL )
              )
      ) ;