msyql学习-
1：学生表
2：成绩表
1.查询所有学生的数学成绩，显示学生姓名name, 分数， 由高到低
select s.name,g.kemu,g.score from student s,grade g where s.id=g.id and g.kemu="数学" order by g.score desc
select s.name,g.kemu,g.score from student s,grade g where s.id=g.id and g.kemu="数学" order by g.score desc
2.统计每个学生的总成绩,显示字段：姓名，总成绩
select s.name, sum(g.score) from student s inner join grade g on s.id=g.id group by s.name
select s.name, sum(g.score) from student s inner join grade g on s.id=g.id group by s.name
3.统计每个学生的总成绩（由于学生可能有重复名字）,显示字段：学生id，姓名，总成绩
select s.id,s.name, sum(g.score) from student s inner join grade g on s.id=g.id group by s.id order by s.id
select s.id,s.name, sum(g.score) from student s inner join grade g on s.id=g.id group by s.id order by s.id
4.列出各门课程成绩最好的学生， 要求显示字段: 学号，姓名,科目，成绩
select s.id,s.name,g.kemu, max(g.score) from student s inner join grade g on s.id=g.id group by g.kemu
select s.id,s.name,g.kemu, max(g.score) from student s inner join grade g on s.id=g.id group by g.kemu
