查询语句sql

SELECT courseNo 课程编号, sum(result) 课程总分,avg(result) 平均成绩,max(result) 最高分, min(result) 最低分,count(result) 参考人数 FROM score group by courseNo order by avg(result) desc # 根据平均分倒序排列 ; # 结束的分号 select count(*) from score where courseNo PU0001;SELECT * FROM score inner join student; select count(*) from score; select count(*) from student; select (select count(*) from score) * (select count(*) from student) 笛卡尔等与n*m; # 去掉笛卡尔积筛选有用的数据 SELECT * FROM score inner join student on score.studentNo student.studentNo; SELECT * FROM student left join score on score.studentNo student.studentNo; # 去掉无用信息 SELECT student.studentNo 学生编号,studentName 学生名称,count(*) 参与考试数量, sum(result) 学生总分 FROM score inner join student on score.studentNo student.studentNo group by student.studentNo having count(*)2 order by sum(result) desc;SELECT * FROM scoreinner join student; select counr(*) from score; select counr(*) from student; select (select count(*) from score) * (selece count(*) from student) 笛尔卡等于n*m; SELECT * FROM score inner join student on score.studentNo student.studentNo; SELECT * FROM student left join score on score.studentNo student.studentNo; SELECT student.studentNo 学生编号,studentName 学生名称,count(*) 参与考试数量, sum(result) 学生总分 FROM scoreinner join student on score.studentNo student.studentNo group by student.studentNo having count(*)2 order by su(result) desc;# 课程的具体数值 select c.courseNo 课程编号,c.courseName 课程名称, sum(result) 科目总分,avg(result) 科目平均分,max(result) 最高分, min(result) 最低分,count(result) 参与考试人数 from score as s inner join course as c on s.courseNo c.courseNo group by s.courseNo having count(result) 5 order by avg(result) desc;