select t.course_id , t.course_name , round(100 * avg(case when t.attend_time >= 10 then 1 else 0 end), 2) as attend_rate from( select c.course_id , c.course_name , b.user_id , sum(case when time(a.out_datetime) > '19:00:00' then timestampdiff(minute, if(time(a.in_datetime) < '19:00:00', str...