mysql - 日期列的 MySQL 条件 ORDER BY ASC/DESC

Question

我需要一个日期时间字段的 MySQL 条件 ORDER BY 语句。我有一张桌子，上面有我想按以下方式订购的帖子：所有未来的帖子都应该按ASC排序，所有历史帖子都应该按DESC排序。例如。：

post_status     post_date     post_title
===========     =========     ==========
future          2012-10-01    Title 1
future          2012-12-01    Title 2
publish         2012-05-01    Title 3
publish         2012-01-01    Title 4

我需要类似于以下 SQL 的东西...

SELECT post_status, post_date, post_title FROM wp_posts
WHERE post_status IN ('future', 'publish')
ORDER BY post_status ASC,
 CASE post_status 
  WHEN 'future' THEN 'post_date ASC'
  ELSE 'post_date DESC'
 END;

关于如何做到这一点的任何提示？谢谢！

Answer 1

试试这个：

ORDER BY post_status ASC,
CASE post_status WHEN 'future' THEN POST_DATE END ASC,
CASE WHEN post_status <> 'future' THEN post_date END DESC

Answer 2

试试这个——

SELECT
  post_status, post_date, post_title
FROM
  wp_posts
WHERE
  post_status IN ('future', 'publish')
ORDER BY
  IF(post_status = 'future', 0, 1),
  IF(post_status = 'future', TO_DAYS(post_date), TO_DAYS(post_date) * -1);

Answer 3

这样的事情怎么样？选择两次并合并结果。

Select * from (SELECT post_status, post_date, post_title 
FROM wp_posts WHERE post_status IN ('future') 
ORDER BY post_status ASC  ) alias1  
UNION
Select * from (SELECT post_status, post_date, post_title 
FROM wp_posts WHERE post_status IN ('publish') 
ORDER BY post_status DESC ) alias2  

Answer 4

我会使用一个union all, 技巧 in order bycan't use index 并且速度较慢。

SELECT * FROM
((SELECT
  1 AS a, @rownum:=@rownum+1 B, post_status, post_date, post_title
FROM
  wp_posts, (SELECT @rownum:=0) r 
WHERE
  post_status='publish'
ORDER BY
  post_date DESC)
UNION ALL
(SELECT
  2 AS a,  @rownum:=@rownum+1 B, post_status, post_date, post_title
FROM
  wp_posts, (SELECT @rownum:=0) r2
WHERE
  post_status='future'
ORDER BY
  post_date)) ORDER BY A,B;