cielpupu

摘要： 搜集自网上资料 查询所有学生的学号、姓名、选课数、总成绩 select a.学号,a.姓名,count(b.课程号) as 选课数,sum(b.成绩) as 总成绩from student as a left join score as bon a.学号 = b.学号group by a.学号; 查 阅读全文