sql语句 - 请教关于mysql分组查询统计数据的问题

Answer 1

I found the answer myself. Reference here
http://blog.csdn.net/swweb/ar...

The core statement is modified as follows:

SELECT `task_id`, MAX(`send_time`) AS `day` FROM `game_work` GROUP BY `task_id` ORDER BY `day` DESC

Answer 2

select sum(num) as num, task_id, day from tablename group by day task_id order by day desc limit 1,30