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;