sql

SELECT count(aa.sex) from (select DISTINCT * FROM s where sex='女') as aa;
select aa.subject,AVG(aa.score) FROM (SELECT * from s where sex='女')as aa GROUP BY subject;

select * FROM s LEFT JOIN student_class on s.s_id=student_class.s_id HAVING c_name='一班' &&(score>80||score in (60,61,62))