SQL SELECT Ordering columns with Null Values

...or in order to avoid value clashing...

SELECT 
   ColumnA, 
   ColumnB
FROM YourTable
ORDER BY 
   CASE WHEN ColumnB IS NULL THEN 1 ELSE 0 END ASC,
   ColumnB

http://stackoverflow.com/questions/5492589/sql-select-ordering-columns-with-null-values