Order by Column1 if Column1 is not null, otherwise order by Column2

Question

Is there a way to combine ORDER BY and IS NULL in sql so that I can order by a column if the column isn't null, but if it is null, order by another column?

Answer 1

Something like:

ORDER BY CASE      WHEN Column1 IS NOT NULL THEN Column1     ELSE Column2 END 

Same as writing:

ORDER BY COALESCE(Column1, Column2) 

Both should work in any sane RDBMS.

Answer 2

Try this

  ORDER BY COALESCE(fieldA, fieldB);