Question

     SELECT old.REF_ID, old.DATE FROM REFID_HISTORY old 
     INNER JOIN REFID_HISTORY new 
     ON new.REF_ID = old.REF_ID 
UNION
     SELECT new.REF_ID, new.DATE FROM REFID_HISTORY new
     INNER JOIN REFID_HISTORY old
     ON new.REF_ID = old._REF_ID
ORDER BY DATE DESC;

上面的脚本显示了REFID的家谱。 REF_ID如何在不选择的情况下对DATE进行排序？

Answer 1

将查询用作子查询，然后仅选择要显示的列。像这样：

SELECT REF_ID
FROM (
      SELECT old.REF_ID, old.DATE FROM REFID_HISTORY old 
      INNER JOIN REFID_HISTORY new 
      ON new.REF_ID = old.REF_ID 
      UNION
      SELECT new.REF_ID, new.DATE FROM REFID_HISTORY new
      INNER JOIN REFID_HISTORY old
      ON new.REF_ID = old._REF_ID
     ) t
ORDER BY DATE DESC;

我创建了一个示例演示看看：

http://sqlfiddle.com/#!4/d5e9e8/3

<强>编辑： 问。对于Cust_ID ='ABC123'

SELECT REF_ID
FROM (
      SELECT old.REF_ID, old.CUST_ID,old.DATE FROM REFID_HISTORY old 
      INNER JOIN REFID_HISTORY new 
      ON new.REF_ID = old.REF_ID 
      UNION
      SELECT new.REF_ID, new.CUST_ID, new.DATE FROM REFID_HISTORY new
      INNER JOIN REFID_HISTORY old
      ON new.REF_ID = old._REF_ID
     ) t
WHERE CUST_ID = 'ABC123'
ORDER BY DATE DESC;

Answer 2

我没有得到查询。为什么不这样做？

SELECT h.REF_ID
FROM REFID_HISTORY h
ORDER BY h.DATE DESC;

这似乎比你的方法简单得多。

按列排序数据而不在SELECT列表中

2 个答案: