LeetCode--511. 游戏玩法分析 I

建表

create table activity ( player_id int, device_id int, event_date date, games_played int ); insert into activity values(1, 2, '2016-03-01', 5); insert into activity values(1, 2, '2016-05-02', 6); insert into activity values(2, 3, '2017-06-25', 1); insert into activity values(3, 1, '2016-03-02', 0); insert into activity values(3, 4, '2018-07-03', 5); select player_id, min(event_date) first_login from activity GROUP BY player_id