WordPress 查询帮助

Question

尝试构建一个有点复杂的 WordPress 查询。在一个查询中，我试图：

1. 拉出所有 WordPress 作者
2. 仅限发表过 10 篇或更多帖子的作者（我遇到的问题）
3. 按最新帖子对作者进行排序。

这是我原来的查询：

SELECT wp_users.ID, display_name, user_url, user_email, MAX(post_date) as date FROM wp_users, wp_posts WHERE wp_users.ID = wp_posts.post_author AND wp_posts.post_status = 'publish' AND wp_posts.post_type = 'post' GROUP BY display_name ORDER BY date DESC;

此查询返回所有作者，甚至那些发表文章不超过 9 篇的作者。

这里是帖子计数的查询：

SELECT wp_users.ID, display_name, user_url, user_email, MAX(post_date) as date, COUNT(post_date) as post_count FROM wp_users, wp_posts WHERE wp_users.ID = wp_posts.post_author AND wp_posts.post_status = 'publish' AND wp_posts.post_type = 'post' GROUP BY display_name ORDER BY date DESC;

在这个查询中你可以看到我已经添加了：

COUNT(post_date) as post_count

它完美地返回了一切。

只有当我添加这个 WHERE 子句时，查询才会中断

post_count > 9

我收到此错误消息：

“where 子句”中的未知列“post_count”

知道为什么会这样吗？我的理论：

1. 不适用于分组
2. 或者 MySQL 不允许超过一个 AS 语句

如果你能解释一下，我将不胜感激。

谢谢。

Answer 1

更改查询post_count > 9的WHERE部分中的条件

HAVING post_count > 9 在GROUP BY 之后

最终查询将是SELECT wp_users.ID, display_name, user_url, user_email, MAX(post_date) as date, COUNT(post_date) as post_count FROM wp_users, wp_posts WHERE wp_users.ID = wp_posts.post_author AND wp_posts.post_status = 'publish' AND wp_posts.post_type = 'post' GROUP BY display_name HAVING post_count > 9 ORDER BY date DESC;

Answer 2

您正在寻找“HAVING”运算符。

SELECT wp_users.ID, display_name, user_url, user_email, MAX(post_date) as date, COUNT(post_date) as post_count FROM wp_users, wp_posts WHERE wp_users.ID = wp_posts.post_author AND wp_posts.post_status = 'publish' AND wp_posts.post_type = 'post' GROUP BY display_name HAVING post_count>9 ORDER BY date DESC;