Question

我大部分时间都在努力解决这个问题所以我想是时候问专家了：我正在尝试在WordPress之外访问我的WordPress数据库，所以我正在编写查询以从稍微复杂的WordPress数据库中获取输出。
数据库中有几个表使用meta_values和meta_keys存储多行中的帖子或用户数据。
例如，我需要从中获取四个表：

表：wp_postmeta

post_id  |    meta_key     |  meta_value
---------+-----------------+------------
2001     | _customer_user  | 3
2001     |order_description| smith
2001     | _order_total    | 300

表：wp_posts

ID  | post_type | post_status
----+-----------+------------
2001| shop_order| publish

表：wp_term_relationships

object_id | term_taxonomy_id
----------+-----------------
 2001     |  190

表：wp_usermeta

user_id  | meta_key        |meta_value
---------+-----------------+----------
  3      | first_name      | Andy
  3      | last_name       | Mccormick

我的查询非常有效，可以在一行中显示订单号（post_id）客户ID，订单描述和订单总数：

 SELECT wp_posts.ID, wp_posts.post_title,ot.meta_value as total,od.meta_value as order_desc, cu.meta_value as customer                
        FROM wp_posts
        LEFT JOIN wp_postmeta AS ot ON (wp_posts.ID = ot.post_id AND ot.meta_key='_order_total')
        LEFT JOIN wp_postmeta AS od ON (wp_posts.ID = od.post_id  AND od.meta_key='order_description')
        LEFT JOIN wp_postmeta AS cu ON (wp_posts.ID =cu.post_id  AND cu.meta_key='_customer_user')
        LEFT JOIN wp_term_relationships ON wp_posts.ID = wp_term_relationships.object_id
        WHERE wp_posts.post_type = 'shop_order'
        AND wp_posts.post_status = 'publish'
        AND wp_term_relationships.term_taxonomy_id = '190'
        GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC"

然而，在另一个领域，我想按名称列出客户，而不仅仅是ID，所以我试图从wp_usermeta表中获取他们的名字和姓氏：

SELECT wp_posts.ID, cu.meta_value as customer, fn.meta_vale as fname, ln.meta_value as lname                
                FROM wp_posts
                LEFT JOIN wp_postmeta AS cu ON (wp_posts.ID = cu.post_id  AND cu.meta_key='_customer_user')
                LEFT JOIN wp_usermeta AS fn ON (cu.meta_key = fn.user_id AND fn.meta_key='first_name')
                LEFT JOIN wp_usermeta AS ln ON (cu.meta_key = ln.user_id AND ln.meta_key='last_name')
                LEFT JOIN wp_term_relationships ON wp_posts.ID = wp_term_relationships.object_id
                WHERE wp_posts.post_type = 'shop_order'
                AND wp_posts.post_status = 'publish'
                AND wp_term_relationships.term_taxonomy_id = '190'
                GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC;

我也尝试过： LEFT JOIN wp_usermeta AS fn ON（（cu.meta_key ='_ customer_user'）= fn.user_id AND fn.meta_key ='first_name'）以及许多其他子查询等。

显然我现在高于我在SQL查询中的薪水等级，所以任何帮助都会很棒。谢谢！

Answer 1

我不确定，但你可以试试这个：

SELECT wp_posts.ID, cu.meta_value as customer, fn.meta_vale as fname, ln.meta_value as lname                
                FROM wp_posts
                LEFT JOIN wp_postmeta AS cu ON (wp_posts.ID = cu.post_id  AND cu.meta_key='_customer_user')
                LEFT JOIN wp_usermeta AS fn ON (cu.meta_value = fn.user_id AND fn.meta_key='first_name') // Note meta_value instead of meta_key
                LEFT JOIN wp_usermeta AS ln ON (cu.meta_value = ln.user_id AND ln.meta_key='last_name') // Note meta_value instead of meta_key
                LEFT JOIN wp_term_relationships ON wp_posts.ID = wp_term_relationships.object_id
                WHERE wp_posts.post_type = 'shop_order'
                AND wp_posts.post_status = 'publish'
                AND wp_term_relationships.term_taxonomy_id = '190'
                GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC;

根据我的想法，cu.meta_value在您的示例中为3，因为它是用户的ID，而cu.meta_key（在您的查询中）是'_customer_id'，所以您宁愿匹配cu.meta_value而不是cu.meta_key。但是无法检查，因为我没有安装WP。

将表连接到自己和彼此

1 个答案: