软件测试⾯试题中的sql题⽬
上海易号⽹络科技有限公司-----测试⾯试题之⼀
软件测试⾯试题中的sql题⽬
1.
学⽣表(学⽣id,姓名,性别,分数)student(s_id,name,sex,score)
班级表(班级id,班级名称)class(c_id,c_name)
学⽣班级表(班级id,学⽣id)student_class(s_id,c_id)
1.查询⼀班得分在80分以上的学⽣
2.查询所有班级的名称,和所有版中⼥⽣⼈数和⼥⽣的平均分
题解:
1.select *from student where score>80and s_id
in( select sid from student_class where c_id=(select c_id from class where c_name='⼀班'))
2.select c.c_name,⼥⽣⼈数=sum(s.s_id),平均分= avg(s.score)from classes c
innerjoin student_class sc on sc.c_id=c.c_id
innerjoin students s on s.s_id=sc.s_idwhere s.sex='⼥' group by c.c_name
2.⼀道SQL语句⾯试题,关于group by表内容:
info 表
date result
2005-05-09 win
2005-05-09 lose
2005-05-09 lose
2005-05-09 lose
2005-05-10 win
2005-05-10 lose
2005-05-10 lose
如果要⽣成下列结果, 该如何写sql语句?
win lose
2005-05-09 2 2
答案:
(1) select date , sum( case when result = "win" then 1 else 0 end ) as "win",
sum(case when result = "lose" then 1 else 0 end) as "lose" from info group by date;
(2) select a.date, a.result as win, b.result as lose from
(select date, count (result) as result from info where result = "win" group by date) as a
join
(select date, count (result) as result from info where result = "lose" group by date) as b
on a.date = b.date;2.学⽣成绩表(stuscore):
3.表中有A B C三列,⽤SQL语句实现:当A列⼤于B列时选择A列否则选择B列,当B列⼤于C列时选择B列否则选择C列
select ( case when a > b then a else b end ), (case when b > c then b else c end ) from table;
4.
有⼀张表,⾥⾯有3个字段:语⽂,数学,英语。其中有3条记录分别表⽰语⽂70分,数学80分,英语58分,请⽤⼀条sql语句查询出这三条记录并按以下条件显⽰出来(并写出您的思路):?
⼤于或等于80表⽰优秀,⼤于或等于60表⽰及格,⼩于60分表⽰不及格。?
显⽰格式:?
语⽂ 数学 英语?
及格 优秀 不及格?
select
(case when 语⽂>=80 then '优秀'
when 语⽂>=60 then '及格'
else'不及格')as语⽂,
(case when 数学>=80 then '优秀'
when 数学>=60 then '及格'
else'不及格')as数学,
(case when 英语>=80 then '优秀'
when 英语>=60 then '及格'
else'不及格')as英语,
from table
5.姓名:name 课程:subject 分数:score 学号:stuid
张三 数学 89 1
张三 语⽂ 80 1
张三 英语 70 1
李四 数学 90 2
李四 语⽂ 70 2
李四 英语 80 2
题解:
1.计算每个⼈的总成绩并排名(要求显⽰字段:姓名,总成绩)
答案:多表查询sql语句面试题
select name,sum(score) as allscore from stuscore group by name order by allscore
2.计算每个⼈的总成绩并排名(要求显⽰字段: 学号,姓名,总成绩)
答案:
select distinct t1.name,t1.stuid,t2.allscore from stuscore t1,( select stuid,sum(score) as allscore from stuscore group by stuid)t2where t1.stuid=t2.stuidorder by t2.allscore desc
3.计算每个⼈单科的最⾼成绩(要求显⽰字段: 学号,姓名,课程,最⾼成绩)
答案:
select t1.stuid,t1.name,t1.subject,t1.score from stuscore t1,(select stuid,max(score) as maxscore from stuscore group by stuid) t2where t1.stuid=t2.stuid an d t1.score=t2.maxscore
4.计算每个⼈的平均成绩(要求显⽰字段: 学号,姓名,平均成绩)
答案:
select distinct t1.stuid,t1.name,t2.avgscore from stuscore t1,(select stuid,avg(score) as avgscore fro
m stuscore group by stuid) t2where t1.stuid=t2.stuid
5.列出各门课程成绩最好的学⽣(要求显⽰字段: 学号,姓名,科⽬,成绩)
答案:
select t1.stuid,t1.name,t1.subject,t2.maxscore from stuscore t1,(select subject,max(score) as maxscore from stuscore group by subject) t2where
t1.subject=t2.subject and t1.score=t2.maxscore
6.列出各门课程成绩最好的两位学⽣(要求显⽰字段: 学号,姓名,科⽬,成绩)
答案:
select distinct t1.* from stuscore t1 where t1.id in (select top 2 stuscore.id from stuscore where subject = t1.subject order by score desc) order by
t1.subject
7.统计如下:学号 姓名 语⽂ 数学 英语 总分 平均分
答案:
select stuid as 学号,name as 姓名,sum(case when subject=’语⽂’ then score else 0 end) as 语⽂,sum(case when subject=’数学’ then score else 0 end) as 数学,sum(case when subject=’英语’ then score else 0 end) as 英语,sum(score) as 总分,(sum(score)/count(*)) as 平均分from stuscoregroup by stuid,name order by 总分desc
*8.列出各门课程的平均成绩(要求显⽰字段:课程,平均成绩)
答案:
*select subject,avg(score) as avgscore from stuscoregroup by subject
9.列出数学成绩的排名(要求显⽰字段:学号,姓名,成绩,排名)
答案:
declare @tmp table(pm int,name varchar(50),score int,stuid int)
insert into @tmp select null,name,score,stuid from stuscore where subject=’数学’ order by score desc
declare @id int
set @id=0;
update @tmp set @id=@id+1,pm=@id
select * from @tmp
oracle:
select DENSE_RANK () OVER(order by score desc) as row,name,subject,score,stuid from stuscore where subject=’数学’order by score desc
ms sql(最佳选择)
select (select count(*) from stuscore t1 where subject =’数学’ and t1.score>t2.score)+1 as row ,stuid,name,score from stuscore t2 where subject =’数学’ ord er by score desc
10.列出数学成绩在2-3名的学⽣(要求显⽰字段:学号,姓名,科⽬,成绩)
答案:select t3.* from(select top 2 t2.* from (select top 3 name,subject,score,stuid from stuscore wh
ere subject=’数学’order by score desc) t2 order by
t2.score) t3 order by t3.score desc
11.求出李四的数学成绩的排名
答案:
declare @tmp table(pm int,name varchar(50),score int,stuid int)insert into @tmp select null,name,score,stuid from stuscore where subject=’数学’ order by s core descdeclare @id intset @id=0;update @tmp set @id=@id+1,pm=@idselect * from @tmp where name=’李四’
12.统计如下:课程 不及格(0-59)个 良(60-80)个 优(81-100)个
答案:select subject, (select count(*) from stuscore where score<60 and subject=t1.subject) as 不及格,(select count(*) from stuscore where score between 60 and 80 and subject=t1.subject) as 良,(select count(*) from stuscore where score >80 and subject=t1.subject) as 优from stuscore t1 group by subject
13.统计如下:数学:张三(50分),李四(90分),王五(90分),赵六(76分)
答案:
declare @s varchar(1000)set @s=”select @s =@s+’,’+name+'(‘+convert(varchar(10),score)+’分)’ from stuscore where subject=’数学’ set @s=stuff(@s,1,1,”)print ‘数学:’+@s
14.计算科科及格的⼈的平均成绩
答案:
select distinct t1.stuid,t2.avgscore from stuscore t1,(select stuid,avg(score) as avgscore from stuscore group by stuid ) t2,(select stuid from stuscore where score<60 group by stuid) t3 where t1.stuid=t2.stuid and t1.stuid!=t3.stuid;
select name,avg(score) as avgscore from stuscore s where (select sum(case when i.score>=60 then 1 else 0 end) from stuscore i where i.name= s.name )=3 group by name
1. ⽤⼀条SQL 语句查询出每门课都⼤于80 分的学⽣姓名
name kecheng fenshu
张三 语⽂ 81
张三 数学 75
李四 语⽂ 76
李四 数学 90
王五 语⽂ 81
王五 数学 100
王五 英语 90
A:
select distinct name from table where name not in (select distinct name from table where fenshu<=80)
select name from table group by name having min(fenshu)>80
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