SELECT *
FROM (SELECT id,value,create_time FROM `table_a` ORDER BY create_time DESC) test
GROUP BY id
ORDER BY create_time DESC
LIMIT 0,30
SELECT a.id, a.value, a.create_time
FROM `table_a`
LEFT JOIN (SELECT id,max(create_time) AS toptime FROM `table_a` GROUP BY id) as b ON a.id=b.id
WHERE a.create_time=b.toptime
ORDER BY a.create_time DESC
LIMIT 0,30
以上两个sql分别要9秒和6秒。共有一百多万条数据，求教怎样能够快点，需分页，最好做到1秒以内。多次查询也可以。
天盟APP下载
