请教sql

access下。这样的sql问题在哪里？
t_score
id dt_id time prog_2 prog_10
1 12 19:20 true false

t_grp_dt
dt_id grp prog_2 prog_10
12 1 true false
select id,count(*) as 总台数,(max(time)-min(time)) as 花费时间 from t_score group by id having dt_id in (select dt_id from t_grp_dt where prog_2=true)