create database DBMonth1 use DBMonth1 create table Student ( SID int primary key identity, Sname varchaR(50), Sage datetime, Ssex varchar(50) ) create table Teacher ( TID int primary key identity, Tname varchar(50), ) create table Course ( CID int primary key identity, Cname varchar(50), TID int foreign key references Teacher(TID) ) create table Score ( ID int primary key identity, SID int foreign key references Student(SID), CID int foreign key references Course(CID), Scores int ) insert into Student values( ‘趙雷’ , ‘1990-01-01’ , ‘男’); insert into Student values( ‘錢電’ , ‘1990-12-21’ , ‘男’); insert into Student values( ‘孫風’ , ‘1990-05-20’ , ‘男’); insert into Student values( ‘李雲’ , ‘1990-08-06’ , ‘男’); insert into Student values( ‘周梅’ , ‘1991-12-01’ , ‘女’); insert into Student values( ‘吳蘭’ , ‘1992-03-01’ , ‘女’); insert into Student values( ‘鄭竹’ , ‘1989-07-01’ , ‘女’); insert into Student values( ‘王菊’ , ‘1990-01-20’ , ‘女’); select * from Student

insert into Teacher values( ‘秦紅山’); insert into Teacher values( ‘李凡’); insert into Teacher values( ‘於彥強’);

select * from Teacher

insert into Course values( ‘語文’ , 2); insert into Course values( ‘數學’ , 1); insert into Course values( ‘英語’ , 3);

insert into Score values(1,1,80); insert into Score values(1,2,56); insert into Score values(1,3,88); insert into Score values(2,1,60); insert into Score values(2,2,70); insert into Score values(2,3,90); insert into Score values(3,1,95); insert into Score values(3,2,86); insert into Score values(3,3,99); insert into Score values(4,1,77); insert into Score values(4,2,44); insert into Score values(4,3,88); insert into Score values(5,1,66); insert into Score values(5,2,85); insert into Score values(5,3,88); insert into Score values(6,1,83); insert into Score values(6,2,88); insert into Score values(6,3,83); insert into Score values(7,2,40); insert into Score values(8,3,90); insert into Score values(8,1,30);

–1、查詢”1”課程比”2”課程成績高的學生的資訊及課程分數 –答： select a.*,b.Scores[課程1的分數], c.Scores[課程2的分數] from Student a,Score b,Score c where a.SID=b.SID and b.SID=c.SID and b.CID=1 and c.CID =2 and b.Scores>c.Scores –.2、查詢同時存在”01”課程和”02”課程的情況和不存在”01”課程但存在”02”課程的情況 –答 –1

–3、查詢平均成績大於等於60分的同學的學生編號和學生姓名和平均成績 –答： select a.Sname[學生姓名],cast(avg(b.Scores) AS decimal(18,2))[平均分] from Student a , Score b where a.SID=b.SID group by a.Sname having cast(avg(b.Scores) AS decimal(18,2))<60 –4、查詢在sc表中不存在成績的學生資訊的SQL語句。 –答： select a.Sname[學生姓名],cast(avg(b.Scores) AS decimal(18,2))[平均分] from Student a left join Score b on a.SID=b.SID group by a.Sname having cast(avg(b.Scores) AS decimal(18,2))<60 –5、查詢所有同學的學生編號、學生姓名、選課總數、所有課程的總成績 –答： select a.Sname[姓名],count(b.CID)[選課總數],SUM(Scores)[總成績] from Student a ,Score b where a.SID=b.SID group by a.Sname

–6、查詢”李”姓老師的數量 –答 select count(Tname) [李姓老師的數量] from Teacher where Teacher.Tname like ‘李%’ –7、查詢學過”秦紅山”老師授課的同學的資訊 –答： select distinct Student.* from Student ,Score,Course,Teacher where Student.SID=Score.SID and Score.CID=Course.CID and Course.TID=Teacher.TID and Teacher.Tname=’秦紅山’

–8、查詢沒學過”秦紅山”老師授課的同學的資訊 –答： select Student.Sname[學生姓名] from Student where SID not in( select distinct SID from Score,Course,Teacher where Score.CID=Course.CID and Course.TID=Teacher.TID and Teacher.Tname=’秦紅山’)

–9、查詢學過編號為”01”並且也學過編號為”02”的課程的同學的資訊 –答： select Sname[學生姓名] from Student where SID IN( select SID from ( select SID from Score where Score.CID=1 union all select SID from Score where Score.CID=2) t group by SID having COUNT(*)=2 ) –10、查詢學過編號為”01”但是沒有學過編號為”02”的課程的同學的資訊 –答：正確的SID是8 這個不會

create view Score2 as select * from Score

select a.Sname[學生姓名] from Student a ,Score b where a.SID=b.SID and b.CID=1 and not exists( select distinct Score.SID from Score ,Score2 where Score.SID=Score2.SID and Score2.CID=2 )

–11、查詢沒有學全所有課程的同學的資訊、 –答： select Student.Sname[學生姓名] from Student ,Score where Student.SID=Score.SID group by Sname having count(CID)<(select count(CID) FROM Course)

–12、查詢和”01”號的同學學習的課程完全相同的其他同學的資訊 –答：錯誤 select Student.Sname[學生姓名] from Student where SID IN ( select * from Score where SID=1 and Score.CID in (select CID from Score where SID=1) group by Score.SID having count(1)=(select count(*) from Score where SID=1))

–14、查詢沒學過”秦紅山”老師講授的任一門課程的學生姓名

select Student .* from Student where SID not in( select Score.SID from Score ,Course,Teacher where Score.CID=Course.CID and Course.TID=Teacher.TID and Teacher.Tname=’秦紅山’)

–15、查詢兩門及其以上不及格課程的同學的學號，姓名及其平均成績

select Student.Sname[學生姓名],cast(AVG(Score.Scores) as decimal(18,2))[平均成績] from Student ,Score where Student.SID=Score.SID and Student.SID in( select SID from Score where Scores >60 group by Score.SID having COUNT(1)>=2 ) group by Student.Sname

–16、檢索”01”課程分數小於60，按分數降序排列的學生資訊

select a.* from Student a ,Score b where a.SID=b.SID and b.Scores<60 and b.CID=1 order by Scores DESC

–17、按平均成績從高到低顯示所有學生的所有課程的成績以及平均成績

select Student .Sname[學生姓名] , max(case Course.Cname when ‘語文’ then Score.Scores else null end)[語文], max(case Course.Cname when ‘數學’ then Score.Scores else null end)[數學], max(case Course.Cname when ‘英語’ then Score.Scores else null end)[英語], cast(avg(Score.Scores) as decimal(18,2)) [平均分] from Student left join Score on Student.SID=Score.SID left join Course on Score.CID=Course.CID group by Student.Sname order by [平均分] desc –18、查詢學生平均成績及其名次

select a.Sname[姓名] , cast(avg(b.Scores) as decimal(18,2))[平均分] ,ROW_NUMBER() over (order by cast(avg(b.Scores) as decimal(18,2)) desc ) as [名次] from Student a join Score b on a.SID=b.SID group by a.Sname

select a.Sname[姓名],cast(avg(b.Scores) as decimal(18,2))[平均分],ROW_NUMBER() over(order by cast(avg(b.Scores) as decimal(18,2)) desc ) as [名次] from Student a , Score b where a.SID=b.SID group by a.Sname –19、查詢各科成績前三名的記錄

–20、查詢每門課程被選修的學生數 select CID ,count(SID)[選擇的人數] from Score group by CID –21、查詢出只有兩門課程的全部學生的學號和姓名 select a.Sname[姓名] from Student a ,Score b where a.SID=b.SID group by a.Sname having count(b.CID)=2

–28、查詢男生、女生人數

select count(Ssex) [男生人數] from Student where Ssex=’男’ select count(Ssex) [女生人數] from Student where Ssex=’女’

select sum(case when Ssex=’男’ then 1 else 0 end )[男生人數] , sum(case when Ssex=’女’ then 1 else 0 end )[女生人數] from Student

select case when Ssex=’男’ then ‘男生人數’ else ‘女生人數’ end [男女情況] ,count (1) [人數] from Student group by case when Ssex=’男’ then ‘男生人數’ else ‘女生人數’ end

–29、查詢名字中含有”風”字的學生資訊 select * from Student where Sname like ‘%’+’風’+’%’

–30、查詢同名同性學生名單，並統計同名人數 select Sname[學生姓名],count(*) [人數] from Student group by Sname having count(*)>1

–31、查詢1990年出生的學生名單(注：Student表中Sage列的型別是datetime)

select *from Student where year(Sage)=1990

select * from Student where datediff(yy,Sage,’1990-01-01’)=0

–32、查詢每門課程的平均成績，結果按平均成績降序排列，平均成績相同時，按課程編號升序排列

select a.CID[課程編號],a.Cname[課程名稱] ,cast(avg(b.scores) as decimal(18,2))[平均分] from Course a ,Score b where a.CID=b.CID group by a.CID,a.Cname order by [平均分] desc,a.CID asc

–33、查詢平均成績大於等於85的所有學生的學號、姓名和平均成績

select a.SID [學生編號],a.Sname[學生姓名],cast(avg(b.Scores)as decimal(18,2))[平均分] from Student a,Score b where a.SID=b.SID group by a.SID,a.Sname having cast(avg(b.Scores)as decimal(18,2))>85

–34、查詢課程名稱為”數學”，且分數低於60的學生姓名和分數 select a.Sname[學生姓名],b.Scores[分數] from Student a,Score b,Course c where a.SID=b.SID and b.CID=c.CID and c.Cname=’數學’ group by a.Sname,b.Scores having b.Scores<60

–36、查詢任何一門課程成績在70分以上的姓名、課程名稱和分數；

select a.Sname[學生姓名],b.Scores[分數],c.Cname[課程名稱] from Student a ,Score b,Course c where a.SID=b.SID and b.CID=c.CID group by a.Sname,b.Scores,c.Cname having b.Scores>70 –37、查詢不及格的課程 select a.Sname[學生姓名],b.Scores[分數],c.Cname[課程名稱] from Student a ,Score b,Course c where a.SID=b.SID and b.CID=c.CID group by a.Sname,b.Scores,c.Cname having b.Scores<60

—-38、查詢課程編號為01且課程成績在80分以上的學生的學號和姓名； select a.Sname[學生姓名],b.Scores[分數] from Student a ,Score b where a.SID=b.SID and b.CID=1 group by a.Sname,b.Scores having b.Scores>80

–39、求每門課程的學生人數 select a.CID[課程編號],a.Cname[課程名稱] ,count(*)[學生人數] from Course a,Score b where a.CID=b.CID group by a.CID,a.Cname

–40、查詢選修”秦紅山”老師所授課程的學生中，成績最高的學生資訊及其成績 select top 1 a.Sname [姓名],b.Scores[分數] from Student a,Score b,Course c ,Teacher d where a.SID=b.SID and b.CID=c.CID and c.TID=d.TID and d.Tname=’秦紅山’ group by a.Sname,b.Scores order by b.Scores desc

–41、查詢不同課程成績相同的學生的學生編號、課程編號、學生成績

–42、查詢每門功成績最好的前兩名 select a.CID,a.Scores from Score a where a.Scores in (select top 2 Scores from Score where Score.CID=a.CID order by Scores desc ) order by a.Scores,a.CID desc

–44、檢索至少選修兩門課程的學生學號 select a.SID,a.Sname from Student a ,Score b where a.SID=b.SID group by a.SID,a.Sname having COUNT(b.CID)>=2

–45、查詢選修了全部課程的學生資訊