SQL中的大值

为空标志使用一个额外的列:

order by 
   case when some_table.ord is null then 2 else 1 end ,
   some_table.ord

order by coalesce(some_table.ord, 9999999999)

在甲骨文中,它只是

ORDER BY some_table.ord NULLS LAST

SELECT S.VAL1, S.VAL2, S.VAL3, COALESCE(S.ORD, O.MAX_ORD+1) AS ORD
  FROM SOME_TABLE S,
       (SELECT MAX(ORDER) AS MAX_ORD FROM SOME_TABLE) O
  WHERE S.whatever = whichever AND
        S.something <> something_else
  ORDER BY ORD

不确定MySQL是否允许FROM列表中的子查询。这里的想法是避免使用魔术值来处理NULL情况。