Whats wrong with my query?
'''select round((select count(distinct t1.player_id) from activity t1 inner join activity t2 on t1.event_date=date_sub(t2.event_date, interval 1 day) and t1.player_id=t2.player_id where t1.player_id=t2.player_id)/count(distinct player_id),2) as fraction from activity;