Drei Tabellen, gemeinsame Tabellenabfrage, kann dieses SQL weiter optimiert werden?

SELECT c.username,c.sex,c.attentions,c.fans,a.id,a.content,a.isnum,a.times,a.turm, a.keep,a.comments,a.uid,b.mini,b.mednum,b.maxs
FROM (wb_userinfo c LEFT JOIN wb_weibo a ON c.uid = a.uid)
LEFT JOIN wb_picture b ON a.id = b.wid WHERE a.uid IN(SELECT follow FROM wb_follow WHERE fans = 27) OR a.uid = 27 ORDER BY a.times LIMIT 0,10;

回复内容：

SELECT c.username,c.sex,c.attentions,c.fans,a.id,a.content,a.isnum,a.times,a.turm, a.keep,a.comments,a.uid,b.mini,b.mednum,b.maxs
FROM (wb_userinfo c LEFT JOIN wb_weibo a ON c.uid = a.uid)
LEFT JOIN wb_picture b ON a.id = b.wid WHERE a.uid IN(SELECT follow FROM wb_follow WHERE fans = 27) OR a.uid = 27 ORDER BY a.times LIMIT 0,10;

有用or的可以考虑换成用union来尝试下

<code>(SELECT c.username,c.sex,c.attentions,c.fans,a.id,a.content,a.isnum,a.times,a.turm,a.keep,a.comments,a.uid,b.mini,b.mednum,b.maxs
FROM (wb_userinfo c LEFT JOIN wb_weibo a ON c.uid = a.uid)
LEFT JOIN wb_picture b ON a.id = b.wid WHERE a.uid IN(SELECT follow FROM wb_follow WHERE fans = 27) )
union
(SELECT c.username,c.sex,c.attentions,c.fans,a.id,a.content,a.isnum,a.times,a.turm,a.keep,a.comments,a.uid,b.mini,b.mednum,b.maxs
FROM (wb_userinfo c LEFT JOIN wb_weibo a ON c.uid = a.uid)
LEFT JOIN wb_picture b ON a.id = b.wid WHERE a.uid = 27 )
ORDER BY a.times LIMIT 0,10;</code>

使用建议是拆成简单查询来.

explain

就sql而言，可优化的空间不大，建议拆成若干条简单的sql，在代码里实现最终业务逻辑。

PS:尽量避免在sql里出现

or

不要用beitreten