php - WordPress 查询根据自定义表获取帖子

Question

我有一些常规的 WordPress 帖子，需要按父类别从数据库中获取，并按我在数据库中创建的自定义表的结果排序。

我要检索帖子的父类别(包括子类别)称为 explorer，id 为 29。

自定义表称为 wp_upvotes。在这个表中有几列，但我们唯一关心的列可能是 id 和 postID。我想按 postID 等于 wp_post.ID 的行数对 wp_posts 进行排序，如果没有行其他帖子的那个表，那么它们应该在最后按日期排序。我希望按日期获得最多的 upvotes 和最少的 upvotes。

我试过的查询是这样的(它只返回第一篇文章，而不是所有文章):

$catIDs = array(29,30,31,32);

SELECT wp_posts.*, COUNT(wp_upvotes.id) AS upvotes FROM wp_posts
LEFT JOIN wp_upvotes ON (wp_posts.ID = wp_upvotes.postID)
INNER JOIN wp_term_relationships
ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_term_taxonomy
ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id
AND wp_term_taxonomy.taxonomy = 'category'
AND wp_term_taxonomy.term_id IN (" . implode(',', $catIDs) . "))
AND wp_posts.post_status = 'publish'
ORDER BY upvotes DESC, wp_posts.post_date DESC

当我删除 wp_upvotes 表的 LEFT JOIN 时，它会返回所有正确的帖子。为什么当我使用 LEFT JOIN 时它只返回一行？

SELECT wp_posts.* FROM wp_posts
INNER JOIN wp_term_relationships
ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_term_taxonomy
ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id
AND wp_term_taxonomy.taxonomy = 'category'
AND wp_term_taxonomy.term_id IN (" . implode(',', $catIDs) . "))
AND wp_posts.post_status = 'publish'
ORDER BY wp_posts.post_date DESC

Answer 1

看起来主要因素是出于某种原因使用 ORDER BY wp_posts.ID 使其显示所有行而不是仅显示一行。奇怪但这是我的最终代码来执行我的操作上面想做的:

SELECT wp_posts.*, COUNT(wp_upvotes.id) AS upvotes FROM wp_posts
INNER JOIN wp_term_relationships
ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_term_taxonomy
ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id
AND wp_term_taxonomy.taxonomy = 'category'
AND wp_term_taxonomy.parent = 29)
LEFT JOIN wp_upvotes ON (wp_posts.ID = wp_upvotes.postID)
WHERE wp_posts.post_status = 'publish'
GROUP BY wp_posts.ID
ORDER BY upvotes DESC, wp_posts.post_date DESC