Question

我一直在寻找但我找不到我想要的东西。这就是我所拥有的：

SELECT user_email, post_type
FROM `wp_users`
INNER JOIN `wp_posts` ON wp_users.id = wp_posts.post_author
WHERE post_type LIKE '%topic%'
OR post_type LIKE '%reply%

它带来了我需要的东西：我需要一个查询，向我显示用户的电子邮件以及他做了多少主题和回复（BBPRESS）。

问题在于它带来了所有这些但它并没有告诉我用户做了多少主题/回复。这就是它带来的： http://i.stack.imgur.com/sMymU.png 有没有办法在它重要的地方添加第3列？

Answer 1

条件聚合：

SELECT user_email, 
       SUM(CASE WHEN post_type LIKE '%reply%' THEN 1 ELSE 0 END) AS Replies,
       SUM(CASE WHEN post_type LIKE '%topic%' THEN 1 ELSE 0 END) AS Topics
FROM `wp_users`
INNER JOIN `wp_posts` ON wp_users.id = wp_posts.post_author
WHERE post_type LIKE '%topic%' OR post_type LIKE '%reply%'
GROUP BY user_mail

Answer 2

试试这个：

  SELECT user_email,
    SUM(CASE WHEN post_type LIKE '%topic%' THEN 1 ELSE 0 END) AS Topics, 
    SUM(CASE WHEN post_type LIKE '%reply%' THEN 1 ELSE 0 END ) AS Replies
  FROM `wp_users`
  INNER JOIN `wp_posts` ON wp_users.id = wp_posts.post_author
  GROUP BY user_email

MySQL计算具有相同值的行

2 个答案: