Question

我有2个SQL查询，我试图优化以删除＆＃34;使用where;使用临时;使用filesort＆＃34;。

第一次查询：

SELECT DISTINCT M.pseudo , M.id as id , CM.send FROM `chat_messages` CM
inner JOIN `uniic_member` M 
ON ((CM.`receiver_id` = 22141 AND M.id=CM.sender_id and CM.`status` != 2)
OR (CM.`sender_id` = 22141 AND M.id=CM.receiver_id AND CM.`status` != 1))
GROUP BY pseudo ORDER BY send DESC;

第二个查询：

SELECT e.*, p.filename AS photo, m.pseudo AS pseudo, m.gender AS gender 
FROM uniic_mailbox AS e 
 LEFT JOIN uniic_member AS m ON m.id = e.sender_id LEFT JOIN uniic_photos AS p 
     ON (m.id = p.member_id AND p.main_photo = 1) WHERE e.status IN (0,1) 
     AND e.member_id = 2248 AND e.sender_id 
     NOT IN (SELECT ban_id FROM uniic_blacklist WHERE member_id = 2248) 
     AND e.created_at = (SELECT MAX(created_at) FROM uniic_mailbox 
     WHERE status IN (0,1) AND member_id = 2248 AND sender_id = e.sender_id LIMIT 1) 
     GROUP BY e.id ORDER BY e.created_at DESC LIMIT 0 , 11;

请告诉我有什么方法可以修复＆＃34;使用where;使用临时;使用filesort＆＃34;并改善此查询的性能？

优化查询以删除“使用位置;使用临时;使用filesort“

0 个答案: