Sql语句查询成绩大全（Mysql，sqlserver，oracle）常遇笔试题

 

数据结构：

 Mysql

-- 查询各个学生的总分 由高到低排序
select name, sum(score) as Totalscore from student group by name ORDER BY Totalscore DESC;

-- 平均分低于80分的学生及各科成绩
select name, 

sum(case WHEN course='语文' then score ELSE 0 END)  语文,
sum(case WHEN course='数学' then score ELSE 0 END) 数学,

avg(score) as Totalscore from student group by name  HAVING avg(score)<80;

-- 各科平均分
select course, avg(score) as Totalscore from student group by course;

-- 删除总成绩最高的学生 此句在mysql中不支持 请参考Sqlserver
--  delete from student where name in(SELECT  name FROM (select name, avg(score) as Totalscore from student group by name) as t ORDER BY t.Totalscore DESC limit 1);

-- 语文大于80分的 减五分 此句在mysql中不支持 请参考Sqlserver
 update student set score=score-5  
  WHERE  name (
 select name from student  where score>80 and course='语文'  
 ) AND  course='语文'

-- 某一位学生的某一门成绩排名
select name,course,score,
(select count(*) from student t1 where course ='数学' and t1.score > t2.score)+1 as 名次
 from student t2  where course ='数学' and name = '学渣许老师儿' order by score desc;

-- 统计
select name ,
sum(case WHEN course='语文' then score ELSE 0 END)  语文,
sum(case WHEN course='数学' then score ELSE 0 END) 数学,
sum(score) 总成绩,
avg(score) 平均分 from student  group by name;

 

-- 每门课都大于80分的学生
select distinct name from student where name not in (select distinct name from student where score<=80);

--统计
 select course 课程,sum(case when score between 0 and 59 then 1 else 0 end) as  低于60不及格（个）,
 sum(case when score between 60 and 80 then 1 else 0 end) as 60至80良（个）,
 sum(case when score between 81 and 100 then 1 else 0 end) as 80值100优秀（个） from student
 group by course; 

   

Sqlserver

-- 查询各个学生的总分 由高到低排序
select name, sum(score) as Totalscore from student group by name ORDER BY Totalscore DESC;

-- 平均分低于80分的学生及各科成绩
select name,sum(case WHEN course='语文' then score ELSE 0 END)  语文,
sum(case WHEN course='数学' then score ELSE 0 END) 数学, avg(score) as Totalscore from student group by name  HAVING avg(score)<80;

-- 各科平均分
select course, avg(score) as Totalscore from student group by course;

-- 删除总成绩最高的学生
delete from student where name in
(SELECT TOP 1 name FROM (select name, avg(score) as Totalscore from student group by name) as t ORDER BY t.Totalscore DESC);
-- 语文大于80分的 减五分
 update student set score=score-5  
  WHERE  name in (
 select name from student  where score>80 and course='语文'  
 ) AND  course='语文'

-- 查询某一位学生的某一门成绩排名
select name,course,score,
(select count(*) from student t1 where course ='数学' and t1.score > t2.score)+1 as 名次
 from student t2  where course ='数学' and name = '学渣许老师儿' order by score desc;

-- 统计
select name ,
sum(case WHEN course='语文' then score ELSE 0 END)  语文,
sum(case WHEN course='数学' then score ELSE 0 END) 数学,
sum(score) 总成绩,
avg(score) 平均分 from student  group by name;

-- 每门课都大于80分的学生
select distinct name from student where name not in (select distinct name from student where score<=80);

--统计
 select course as 课程,sum(case when score between 0 and 59 then 1 else 0 end) as  低于60不及格（个）,
 sum(case when score between 60 and 80 then 1 else 0 end) as 60至80良（个）,
 sum(case when score between 81 and 100 then 1 else 0 end) as 80值100优秀（个） from student
 group by course;

-- 统计是否及
SELECT  course as 课程,
        SUM(CASE WHEN score>=60 THEN 1 ELSE 0 END) as 及格,
        SUM(CASE WHEN score>=60 THEN 0 ELSE 1 END) as 不及格
FROM  student
GROUP BY  course;　

Oracle

-- 查询各个学生的总分 由高到低排序
select "name",sum("score") as Totalscore from "student" group by "name" ORDER BY Totalscore DESC;

-- 平均分低于80分的学生及各科成绩
select "name", 
sum(case WHEN "course"='语文' then "score" ELSE 0 END)  语文,
sum(case WHEN "course"='数学' then "score" ELSE 0 END) 数学, 
avg("score") as average from  "student" group by "name"  HAVING avg("score")<80;

-- 各科平均分
select "course", avg("score") as  average from "student" group by "course";

-- 删除总成绩最高的学生
delete from "student" where "name" in(
SELECT "name" FROM(select "name", avg("score") as Totalscore from 
"student"  group by "name" ORDER BY Totalscore DESC) where rownum = 1
);
-- 语文大于80分的 减五分
 update "student" set "score"="score"-5  
  WHERE  "name" in (
 select "name" from "student"  where "score">80 and "course"='语文'  
 ) AND  "course"='语文'

-- 查询某一位学生的某一门成绩排名
select "name","course","score",(select count(*) from "student" t1 where "course" ='数学' and t1."score" > t2."score")+1 as 名次
 from "student" t2  where "course" ='数学' and "name" = '学渣许老师儿' order by "score" desc;

-- 统计
select "name" ,
sum(case WHEN "course"='语文' then "score" ELSE 0 END)  语文,
sum(case WHEN "course"='数学' then "score" ELSE 0 END) 数学,
sum("score") 总成绩,
avg("score") 平均分 from "student"  group by "name";

-- 每门课都大于80分的学生
select distinct "name" from "student" where "name" not in (select distinct "name" from "student" where "score"<=80);


-- 统计是否及格
SELECT  "course" as 课程,
        SUM(CASE WHEN "score">=60 THEN 1 ELSE 0 END) as 及格,
        SUM(CASE WHEN "score">=60 THEN 0 ELSE 1 END) as 不及格
FROM  "SYSTEM"."student"
GROUP BY  "course";

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