mysql命令根據條款

Question

我得到一個錯誤，指出： 「未知列‘story2.time’‘以條款’」

我的SQL語句是：

mysql_query("SELECT headline, story2.time FROM story2 WHERE username='Michael' UNION 
SELECT headline, story2.time FROM story2 JOIN subscriptions WHERE subscriptions.subpaperid = story2.artnewsid AND subscriptions.papernameurl = story2.papernameurl AND subscriptions.username = 'Michael' UNION 
SELECT headline, story2.time FROM story2 JOIN bookmark WHERE bookmark.writername = story2.username AND bookmark.articleid = story2.random AND bookmark.username = 'Michael' 
ORDER BY story2.time DESC LIMIT 0,25") or die(mysql_error()); 

上做任何幫助下面的查詢工作將不勝感激。謝謝！

Answer 1

您不能在order by中使用table別名。所以，只是做：

SELECT headline, story2.time 
FROM story2 
WHERE username='Michael' 
UNION 
SELECT headline, story2.time 
FROM story2 JOIN 
    subscriptions 
WHERE subscriptions.subpaperid = story2.artnewsid AND subscriptions.papernameurl = story2.papernameurl AND subscriptions.username = 'Michael' 
UNION 
SELECT headline, story2.time 
FROM story2 JOIN 
    bookmark 
WHERE bookmark.writername = story2.username AND bookmark.articleid = story2.random AND bookmark.username = 'Michael' 
ORDER BY time DESC 
LIMIT 0, 25 

表名是唯一的範圍在每union子查詢。順便說一下，除非您故意要承擔刪除重複項的開銷，否則您應該使用union all。

Answer 2

聯合結果的列名設置爲時間，所以按時間排序。