select sname,ssex,class from t_hq_student; select distinct depart from t_hq_teacher; select * from t_hq_student; select * from t_hq_score where degree between 60 and 80; select * from t_hq_score where degree in ('85','86','88'); select * from t_hq_student where class like'95031' or ssex like '女'; select * from t_hq_student order by class desc; select * from t_hq_score order by cno; select * from t_hq_score order by degree desc; select class, count(1) as 人数 from t_hq_student where class ='95031' group by class; select * from t_hq_score where degree >= all(select degree from t_hq_score); select cno,avg(degree) as 平均成绩 from t_hq_score group by cno; select sno from t_hq_score where degree > 70 and degree < 90;