sql - 每月 Wordpress 帖子数

Question

我需要在 Wordpress 中运行查询以获取每月有多少帖子(包括零)。

我的查询现在返回我要返回的内容的第一部分:

select
distinct date_format(post_date, '%y') "year",
date_format(post_date, '%b') "month",
from wp_posts
where post_type = 'post'
and post_status = 'publish'
group by date_format(post_date, '%y'), date_format(post_date, '%b')
order by date_format(post_date, '%y') desc, post_date

它返回如下内容:

|   year   |   month   |   count   |
------------------------------------
|   10     |   Jan     |     4     |
|   10     |   Feb     |     2     |
|   10     |   Mar     |     1     |
|   10     |   Apr     |     6     |
|   09     |   Jan     |     4     |
|   09     |   Feb     |     2     |

我需要返回类似的东西:

|   year   |   month   |   count   |
------------------------------------
|   10     |   Jan     |     4     |
|   10     |   Feb     |     2     |
|   10     |   Mar     |     1     |
|   10     |   Apr     |     6     |
|   10     |   May     |     0     |
|   10     |   Jun     |     0     |
|   10     |   Jul     |     0     |
|   10     |   Aug     |     0     |
|   10     |   Sep     |     0     |
|   10     |   Oct     |     0     |
|   10     |   Nov     |     0     |
|   10     |   Dec     |     0     |
|   09     |   Jan     |     4     |
|   09     |   Feb     |     2     |
|   09     |   Mar     |     0     |
|   09     |   Apr     |     0     |
|   09     |   May     |     0     |
|   09     |   Jun     |     0     |
|   09     |   Jul     |     0     |
|   09     |   Aug     |     0     |
|   09     |   Sep     |     0     |
|   09     |   Oct     |     0     |
|   09     |   Nov     |     0     |
|   09     |   Dec     |     0     |

我会在 Oracle 中使用 rownum，但我无法使用 MySQL 语法找出查询。非常感谢任何帮助。

Answer 1

这需要数字表技巧 -

1. 创建一个名为 NUMBERS 的表:

   DROP TABLE IF EXISTS `example`.`numbers`;
   CREATE TABLE  `example`.`numbers` (
     `id` int(10) unsigned NOT NULL auto_increment,
      PRIMARY KEY  (`id`)
   ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
   

2. 通过至少运行以下命令来填充表:

   INSERT INTO NUMBERS (id) VALUES (NULL)
   

这将允许您使用以下方法生成日期列表:

SELECT DATE(DATE_ADD('2009-01-01', INTERVAL n.id MONTH)) AS dt
  FROM NUMBERS n

现在，您可以将当前查询加入到日期列表中:

   SELECT DATE_FORMAT(x.dt, '%y') "year",
          DATE_FORMAT(x.dt, '%b') "month",
          COUNT(*) AS count
     FROM (SELECT DATE_ADD('2009-01-01', INTERVAL n.id MONTH) AS dt
             FROM NUMBERS n) x
LEFT JOIN WP_POSTS wp ON MONTH(wp.post_date) = MONTH(x.dt)
                     AND YEAR(wp.post_date) = YEAR(x.dt)
                     AND wp.post_type = 'post'
                     AND wp.post_status = 'publish'
    WHERE YEAR(x.dt) IN (2009, 2010)
 GROUP BY DATE_FORMAT(x.dt, '%y'), DATE_FORMAT(x.dt, '%b')
 ORDER BY DATE_FORMAT(x.dt, '%y') DESC, MONTH(x.dt)