SQL如下 数据库Mysql
SELECT *
FROM manager_devices md
right JOIN messageed m ON md.uid = m.deviceNumber
JOIN (
SELECT id
FROM messageed
ORDER BY time DESC
) a_order ON m.id = a_order.id
WHERE md.uid IN (23,534,64,134) AND m.time BETWEEN 1472572800 AND 1569772800
也就是想要限制messageed表的查询出来的数量,还需要保证效率的查询。
为什么不左右调换一下位置呢...