WordPress的WP_List_Table排序数据查询问题

如何解决WordPress的WP_List_Table排序数据查询问题

我正在使用wordpress 5.5，PHP 7.4和MysqL 5.7.30 我正在为我的电子商务系统使用woocomerce订阅插件。我想要的是能够在管理面板中显示paginatd订阅的列表并（重要部分）根据管理面板中的“ next_payment_schedule”，“ first_payment_schedule”日期对其进行排序。 woocommerce订阅插件将所有订阅保留为自定义帖子类型，其类型为“ shop_subscription”，并且还将其所有特定字段保留在postMeta表中。

问题是，正如我所说的，该插件将这些日期保留在postMeta表中。我如何同时支持分页和排序？

这是我当前的查询：

SELECT p.id AS post_id,p.post_status,u.id AS user_id,u.user_login,u.user_email,GROUP_CONCAT(pm.Meta_value)
FROM posts AS p
INNER JOIN users AS u ON p.post_author = u.id
INNER JOIN postMeta AS pm ON pm.post_id = p.id 
WHERE post_type = 'shop_subscription'
AND pm.Meta_key in ('_schedule_start','_schedule_next_payment')
GROUP BY p.id
ORDER BY user_login ASC

当我想处理分页时，此查询很好。

，当我想处理排序时，以下查询很好用

SELECT p.id AS post_id,p.post_title,p.post_name,pm.Meta_key,pm.Meta_value from posts AS p
INNER JOIN postMeta AS pm ON pm.post_id = p.id 
INNER JOIN users AS u ON p.post_author = u.id 
WHERE post_type = 'shop_subscription' 
AND pm.Meta_key in ('_schedule_start','_schedule_next_payment') 
ORDER BY CASE WHEN pm.Meta_key IN('_schedule_next_payment') THEN pm.Meta_value END desc

我应该如何处理这种情况？

解决方法

最后，我使用以下查询解决了我的问题：

        $sql = "SELECT p.id AS post_id,p.post_status,u.id AS user_id,u.user_login,u.user_email,pm2.schedule_start,pm2.schedule_next_payment
                FROM `$wpdb->posts` AS p
                INNER JOIN `$wpdb->users` AS u ON p.post_author = u.id
                INNER JOIN (
                    SELECT t.post_id,MAX(t.schedule_start) AS schedule_start,MAX(t.schedule_next_payment) AS schedule_next_payment
                    FROM (
                
                    SELECT 
                            post_id,case when pm.meta_key = '_schedule_start' then pm.meta_value else 0 end AS schedule_start,case when pm.meta_key = '_schedule_next_payment' then pm.meta_value else 0 end AS schedule_next_payment
                            FROM (SELECT * FROM `$wpdb->postmeta` pm where pm.meta_key IN ('_schedule_next_payment','_schedule_start')) AS pm
                    ) AS t
                    GROUP BY t.post_id
                ) 
                
                AS pm2 ON pm2.post_id = p.id
                WHERE post_type = '".self::POST_TYPE."'"

如果您仔细查看以下子查询：

                    SELECT t.post_id,MAX(t.schedule_next_payment) AS schedule_next_payment
                    FROM (
                        SELECT 
                                post_id,case when pm.meta_key = '_schedule_next_payment' then pm.meta_value else 0 end AS schedule_next_payment
                                FROM (SELECT * FROM `$wpdb->postmeta` pm where pm.meta_key IN ('_schedule_next_payment','_schedule_start')) AS pm
                        ) AS t
                    GROUP BY t.post_id

您可以看到我更改了postmeta表的列和行（旋转表），我可以根据这两个日期字段轻松地将其与我的posts表和订单加入。