Open chengchengxu15 opened 2 years ago
Create table If Not Exists Activity (player_id int, device_id int, event_date date, games_played int) Truncate table Activity insert into Activity (player_id, device_id, event_date, games_played) values ('1', '2', '2016-03-01', '5') insert into Activity (player_id, device_id, event_date, games_played) values ('1', '2', '2016-05-02', '6') insert into Activity (player_id, device_id, event_date, games_played) values ('2', '3', '2017-06-25', '1') insert into Activity (player_id, device_id, event_date, games_played) values ('3', '1', '2016-03-02', '0') insert into Activity (player_id, device_id, event_date, games_played) values ('3', '4', '2018-07-03', '5')
/* Write your T-SQL query statement below */ select player_id, min(event_date) as first_login from Activity group by player_id;
忘记了min....