我需要列出具有特定角色的所有用户（自定义角色＆＃39; forhandler＆＃39;），并为每个展示他们在状态已完成＆＃39;，&&的已发布订单上的总计（已花费） ＃39;处理＆＃39;和＆＃39;保持＆＃39;以及每个用户的订单数量计数（也已发布，状态如上）。结果必须先按最高总数排序。
我设法写了一个有效的SQL查询（这是我的SQL知识的限制），但是在生产数据上运行需要20秒+（1200个订单并且增加）。这个查询可以重写为更有效（或更好）的东西吗？
SELECT users.ID, users.display_name,
(SELECT COUNT(posts.ID)
FROM $wpdb->posts AS posts
LEFT JOIN $wpdb->postmeta ON $wpdb->postmeta.post_id = posts.ID
LEFT JOIN $wpdb->term_relationships AS rel ON posts.ID=rel.object_ID
LEFT JOIN $wpdb->term_taxonomy AS tax USING( term_taxonomy_id )
LEFT JOIN $wpdb->terms AS term USING( term_id )
WHERE $wpdb->postmeta.meta_key = '_customer_user'
AND $wpdb->postmeta.meta_value = users.ID
AND posts.post_type = 'shop_order'
AND posts.post_status = 'publish'
AND tax.taxonomy = 'shop_order_status'
AND term.slug IN ('completed', 'processing', 'on-hold')
) AS numOrders,
(
SELECT SUM(postmeta.meta_value)
FROM $wpdb->postmeta AS postmeta
LEFT JOIN $wpdb->posts AS pp ON pp.ID = postmeta.post_id
LEFT JOIN $wpdb->postmeta AS pm2 ON pm2.post_id = postmeta.post_id
LEFT JOIN $wpdb->term_relationships AS rel ON pp.ID=rel.object_ID
LEFT JOIN $wpdb->term_taxonomy AS tax USING( term_taxonomy_id )
LEFT JOIN $wpdb->terms AS term USING( term_id )
WHERE postmeta.meta_key = '_order_total'
AND pm2.meta_key = '_customer_user'
AND pm2.meta_value = users.ID
AND tax.taxonomy = 'shop_order_status'
AND term.slug IN ('completed', 'processing', 'on-hold')
AND pp.post_type = 'shop_order'
AND pp.post_status = 'publish'
) AS totalsOfOrders
FROM wp_users AS users
INNER JOIN wp_usermeta ON users.ID = wp_usermeta.user_id
WHERE wp_usermeta.meta_key = 'wp_capabilities'
AND wp_usermeta.meta_value LIKE '%forhandler%'
ORDER BY totalsOfOrders DESC