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. 只有拥有10个或更多发布帖子的作者（我遇到问题）
3. 按最新帖子排序作者。

这是我的原始查询：

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;

此查询会返回所有作者，甚至包含9个或更少发布帖子的作者。

以下是包含帖子计数的查询：

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;

在此查询中，您可以看到我添加了：

COUNT(post_date) as post_count

它可以很好地回报所有内容。

只有在我添加此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MySQL不允许多个AS语句

如果你能说清楚，我会非常感激。

感谢。

Answer 1

更改查询post_count > 9

的WHERE部分中的条件 在HAVING post_count > 9

之后使用GROUP BY

最终查询将为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”操作员。

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;