java面试题之sql语句

根据这一张表进行sql操作

-- 分组查询总分数
select num,name,SUM(score) as scoreall from score2 GROUP BY name order by scoreall
-- 计算每个人单科最高成绩
select name,MAX(score) from score2 GROUP BY name
-- 计算每个人的平均成绩
select name,AVG(score) from score2 GROUP BY name
-- 列出各科成绩最好的学生
select DISTINCT '最高分',score2.* from score2,(select MAX(score) as score,course from score2 GROUP BY course ) b
where score2.score=b.score

-- 分组统计姓名 语文、数学、英语、总分、平均分
select name as '姓名',SUM(case when course='语文' then score end) as '语文',SUM(case when course='数学' then score end)'数学',
SUM(case when course='英语' then score end)'英语',SUM(score),AVG(score) FROM score2 GROUP BY name

-- 列出数学成绩的排名
select name,course,score from score2 where course='数学' order by score desc

-- 统计课程和对应的优秀、及格、不及格个数
select course,(select COUNT(*) from score2 where course=t.course and score>=80)'优秀',
(select COUNT(*) from score2 where course=t.course and score>=60 and score<80)'良好',
(select COUNT(*) from score2 where course=t.course and score<60)'不及格'
from score2 t GROUP BY course

-- 计算各科都及格的的人的平均成绩
select name,AVG(score) from score2 GROUP BY name having MIN(score)>60