mysql - 如何优化这个完整的查询？

Question

在 mysql 上使用以下查询时，它被锁定，

SELECT event_list.* 
FROM event_list 
    INNER JOIN members 
        ON members.profilenam=event_list.even_loc 
WHERE (even_own IN (SELECT frd_id 
                    FROM network 
                    WHERE mem_id='911' 
                    GROUP BY frd_id) 
           OR even_own = '911' ) 
       AND event_list.even_active = 'y' 
GROUP BY event_list.even_id 
ORDER BY event_list.even_stat ASC

IN约束内的内部查询有很多frd_id，所以因为上面的查询很慢...，所以请帮忙。

谢谢。

Answer 1

试试这个:

SELECT el.* 
FROM event_list el 
INNER JOIN members m ON m.profilenam = el.even_loc 
WHERE el.even_active = 'y' AND 
     (el.even_own = 911 OR EXISTS (SELECT 1 FROM network n WHERE n.mem_id=911 AND n.frd_id = el.even_own))       
GROUP BY el.even_id 
ORDER BY el.even_stat ASC