sqlserver advanced query must know - having query typical practice questions

--

 --1 查询每个专业最高分的课程名和分数 
 select b.Kname 课程名,b.yuwen 课程语文分数,--a.cno,
 a.major as 全部专业,max(a.Grade) as 专业最高分--,--b.cno
 from score a,coures b 
 --1.1 where 课程表的学号，关联成绩表的主键id ,才能获取到全部的专业.
 where  b.cno=a.ID
 --
 group by a.major,a.cno,b.cno,b.Kname,b.yuwen   
 --having  b.cno=a.Cno


 --课程表
 select  * from coures
 --课程仅仅关联课程名字。 其他删除 
 delete  from coures  
 

 
  --成绩表
 select * from score 
 --专业分数sort 
 alter table score add majorscoresort int null;
 
update score set majorscoresort=1 where id<=3
update score set majorscoresort=2 where id<=6 and id>3 
update score set majorscoresort=3 where id<=9 and id>6
update score set majorscoresort=1 where id<=3

 --学生表 
 select  * from st

Effect