mysql多表联查

 1.小虎的数学成绩是多少

SELECT s.name,c.course,ss.score FROM students as s,courses as c,scores as ss
WHERE s.sid=ss.sid and c.cid=ss.cid and s.name="小虎" and c.course="数学"

 2.马老师教了那些课

 3.数学最高分是哪个同学