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java sql2008的增删改查_SQL server数据库增删改查练习

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--創(chuàng)建測試數(shù)據(jù)

create table Student(S# varchar(10),Sname nvarchar(10),Sage datetime,Ssex nvarchar(10))

insert into Student values('01' , N'趙雷' , '1990-01-01' , N'男')

insert into Student values('02' , N'錢電' , '1990-12-21' , N'男')

insert into Student values('03' , N'孫風(fēng)' , '1990-05-20' , N'男')

insert into Student values('04' , N'李云' , '1990-08-06' , N'男')

insert into Student values('05' , N'周梅' , '1991-12-01' , N'女')

insert into Student values('06' , N'吳蘭' , '1992-03-01' , N'女')

insert into Student values('07' , N'鄭竹' , '1989-07-01' , N'女')

insert into Student values('08' , N'王菊' , '1990-01-20' , N'女')

create table Course(C# varchar(10),Cname nvarchar(10),T# varchar(10))

insert into Course values('01' , N'語文' , '02')

insert into Course values('02' , N'數(shù)學(xué)' , '01')

insert into Course values('03' , N'英語' , '03')

create table Teacher(T# varchar(10),Tname nvarchar(10))

insert into Teacher values('01' , N'張三')

insert into Teacher values('02' , N'李四')

insert into Teacher values('03' , N'王五')

create table SC(S# varchar(10),C# varchar(10),score decimal(18,1))

insert into SC values('01' , '01' , 80)

insert into SC values('01' , '02' , 90)

insert into SC values('01' , '03' , 99)

insert into SC values('02' , '01' , 70)

insert into SC values('02' , '02' , 60)

insert into SC values('02' , '03' , 80)

insert into SC values('03' , '01' , 80)

insert into SC values('03' , '02' , 80)

insert into SC values('03' , '03' , 80)

insert into SC values('04' , '01' , 50)

insert into SC values('04' , '02' , 30)

insert into SC values('04' , '03' , 20)

insert into SC values('05' , '01' , 76)

insert into SC values('05' , '02' , 87)

insert into SC values('06' , '01' , 31)

insert into SC values('06' , '03' , 34)

insert into SC values('07' , '02' , 89)

insert into SC values('07' , '03' , 98)

--1、查詢"01"課程比"02"課程成績高的學(xué)生的信息及課程分?jǐn)?shù)

--1.1、查詢同時存在"01"課程和"02"課程的情況

select a.* , b.score [課程'01'的分?jǐn)?shù)],c.score [課程'02'的分?jǐn)?shù)] from Student a , SC b , SC c

where a.S# = b.S# and a.S# = c.S# and b.C# = '01' and c.C# = '02' and b.score > c.score

--1.2、查詢同時存在"01"課程和"02"課程的情況和存在"01"課程但可能不存在"02"課程的情況(不存在時顯示為null)(以下存在相同內(nèi)容時不再解釋)

select a.* , b.score [課程"01"的分?jǐn)?shù)],c.score [課程"02"的分?jǐn)?shù)] from Student a

left join SC b on a.S# = b.S# and b.C# = '01'

left join SC c on a.S# = c.S# and c.C# = '02'

where b.score > isnull(c.score,0)

--2、查詢"01"課程比"02"課程成績低的學(xué)生的信息及課程分?jǐn)?shù)

--2.1、查詢同時存在"01"課程和"02"課程的情況

select a.* , b.score [課程'01'的分?jǐn)?shù)],c.score [課程'02'的分?jǐn)?shù)] from Student a , SC b , SC c

where a.S# = b.S# and a.S# = c.S# and b.C# = '01' and c.C# = '02' and b.score < c.score

--2.2、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

select a.* , b.score [課程"01"的分?jǐn)?shù)],c.score [課程"02"的分?jǐn)?shù)] from Student a

left join SC b on a.S# = b.S# and b.C# = '01'

left join SC c on a.S# = c.S# and c.C# = '02'

where isnull(b.score,0) < c.score

--3、查詢平均成績大于等于60分的同學(xué)的學(xué)生編號和學(xué)生姓名和平均成績

select a.S# , a.Sname , cast(avg(b.score) as decimal(18,2)) avg_score

from Student a , sc b

where a.S# = b.S#

group by a.S# , a.Sname

having cast(avg(b.score) as decimal(18,2)) >= 60

order by a.S#

--4、查詢平均成績小于60分的同學(xué)的學(xué)生編號和學(xué)生姓名和平均成績

--4.1、查詢在sc表存在成績的學(xué)生信息的SQL語句。

select a.S# , a.Sname , cast(avg(b.score) as decimal(18,2)) avg_score

from Student a , sc b

where a.S# = b.S#

group by a.S# , a.Sname

having cast(avg(b.score) as decimal(18,2)) < 60

order by a.S#

--4.2、查詢在sc表中不存在成績的學(xué)生信息的SQL語句。

select a.S# , a.Sname , isnull(cast(avg(b.score) as decimal(18,2)),0) avg_score

from Student a left join sc b

on a.S# = b.S#

group by a.S# , a.Sname

having isnull(cast(avg(b.score) as decimal(18,2)),0) < 60

order by a.S#

--5、查詢所有同學(xué)的學(xué)生編號、學(xué)生姓名、選課總數(shù)、所有課程的總成績

--5.1、查詢所有有成績的SQL。

select a.S# [學(xué)生編號], a.Sname [學(xué)生姓名], count(b.C#) 選課總數(shù), sum(score) [所有課程的總成績]

from Student a , SC b

where a.S# = b.S#

group by a.S#,a.Sname

order by a.S#

--5.2、查詢所有(包括有成績和無成績)的SQL。

select a.S# [學(xué)生編號], a.Sname [學(xué)生姓名], count(b.C#) 選課總數(shù), sum(score) [所有課程的總成績]

from Student a left join SC b

on a.S# = b.S#

group by a.S#,a.Sname

order by a.S#

--6、查詢"李"姓老師的數(shù)量

--方法1

select count(Tname) ["李"姓老師的數(shù)量] from Teacher where Tname like N'李%'

--方法2

select count(Tname) ["李"姓老師的數(shù)量] from Teacher where left(Tname,1) = N'李'

"李"姓老師的數(shù)量

-----------

--7、查詢學(xué)過"張三"老師授課的同學(xué)的信息

select distinct Student.* from Student , SC , Course , Teacher

where Student.S# = SC.S# and SC.C# = Course.C# and Course.T# = Teacher.T# and Teacher.Tname = N'張三'

order by Student.S#

--8、查詢沒學(xué)過"張三"老師授課的同學(xué)的信息

select m.* from Student m where S# not in (select distinct SC.S# from SC , Course , Teacher where SC.C# = Course.C# and Course.T# = Teacher.T# and Teacher.Tname = N'張三') order by m.S#

--9、查詢學(xué)過編號為"01"并且也學(xué)過編號為"02"的課程的同學(xué)的信息

--方法1

select Student.* from Student , SC where Student.S# = SC.S# and SC.C# = '01' and exists (Select 1 from SC SC_2 where SC_2.S# = SC.S# and SC_2.C# = '02') order by Student.S#

--方法2

select Student.* from Student , SC where Student.S# = SC.S# and SC.C# = '02' and exists (Select 1 from SC SC_2 where SC_2.S# = SC.S# and SC_2.C# = '01') order by Student.S#

--方法3

select m.* from Student m where S# in

(

select S# from

(

select distinct S# from SC where C# = '01'

union all

select distinct S# from SC where C# = '02'

) t group by S# having count(1) = 2

)

order by m.S#

--10、查詢學(xué)過編號為"01"但是沒有學(xué)過編號為"02"的課程的同學(xué)的信息

--方法1

select Student.* from Student , SC where Student.S# = SC.S# and SC.C# = '01' and not exists (Select 1 from SC SC_2 where SC_2.S# = SC.S# and SC_2.C# = '02') order by Student.S#

--方法2

select Student.* from Student , SC where Student.S# = SC.S# and SC.C# = '01' and Student.S# not in (Select SC_2.S# from SC SC_2 where SC_2.S# = SC.S# and SC_2.C# = '02') order by Student.S#

--11、查詢沒有學(xué)全所有課程的同學(xué)的信息

--11.1、

select Student.*

from Student , SC

where Student.S# = SC.S#

group by Student.S# , Student.Sname , Student.Sage , Student.Ssex having count(C#) < (select count(C#) from Course)

--11.2

select Student.*

from Student left join SC

on Student.S# = SC.S#

group by Student.S# , Student.Sname , Student.Sage , Student.Ssex having count(C#) < (select count(C#) from Course)

11.3

select c.*

from student c

where exists

(

select *

from course b

where ?not ?exists( select *

from sc a

where a.c#=b.c# and c.s#=a.s#

)

--12、查詢至少有一門課與學(xué)號為"01"的同學(xué)所學(xué)相同的同學(xué)的信息

select distinct Student.* from Student , SC where Student.S# = SC.S# and SC.C# in (select C# from SC where S# = '01') and Student.S# <> '01'

--13、查詢和"01"號的同學(xué)學(xué)習(xí)的課程完全相同的其他同學(xué)的信息

select Student.* from Student where S# in

(select distinct SC.S# from SC where S# <> '01' and SC.C# in (select distinct C# from SC where S# = '01')

group by SC.S# having count(1) = (select count(1) from SC where S#='01'))

--14、查詢沒學(xué)過"張三"老師講授的任一門課程的學(xué)生姓名

select student.* from student where student.S# not in

(select distinct sc.S# from sc , course , teacher where sc.C# = course.C# and course.T# = teacher.T# and teacher.tname = N'張三')

order by student.S#

--15、查詢兩門及其以上不及格課程的同學(xué)的學(xué)號，姓名及其平均成績

select student.S# , student.sname , cast(avg(score) as decimal(18,2)) avg_score from student , sc

where student.S# = SC.S# and student.S# in (select S# from SC where score < 60 group by S# having count(1) >= 2)

group by student.S# , student.sname

--16、檢索"01"課程分?jǐn)?shù)小于60，按分?jǐn)?shù)降序排列的學(xué)生信息

select student.* , sc.C# , sc.score from student , sc

where student.S# = SC.S# and sc.score < 60 and sc.C# = '01'

order by sc.score desc

--17、按平均成績從高到低顯示所有學(xué)生的所有課程的成績以及平均成績

--17.1 SQL 2000 靜態(tài)

select a.S# 學(xué)生編號 , a.Sname 學(xué)生姓名 ,

max(case c.Cname when N'語文' then b.score else null end) [語文],

max(case c.Cname when N'數(shù)學(xué)' then b.score else null end) [數(shù)學(xué)],

max(case c.Cname when N'英語' then b.score else null end) [英語],

cast(avg(b.score) as decimal(18,2)) 平均分

from Student a

left join SC b on a.S# = b.S#

left join Course c on b.C# = c.C#

group by a.S# , a.Sname

order by 平均分 desc

--17.2 SQL 2000 動態(tài)

declare @sql nvarchar(4000)

set @sql = 'select a.S# ' + N'學(xué)生編號' + ' , a.Sname ' + N'學(xué)生姓名'

select @sql = @sql + ',max(case c.Cname when N'''+Cname+''' then b.score else null end) ['+Cname+']'

from (select distinct Cname from Course) as t

set @sql = @sql + ' , cast(avg(b.score) as decimal(18,2)) ' + N'平均分' + ' from Student a left join SC b on a.S# = b.S# left join Course c on b.C# = c.C#

group by a.S# , a.Sname order by ' + N'平均分' + ' desc'

exec(@sql)

--17.3 有關(guān)sql 2005的動靜態(tài)寫法參見我的文章《普通行列轉(zhuǎn)換(version 2.0)》或《普通行列轉(zhuǎn)換(version 3.0)》。

--18、查詢各科成績最高分、最低分和平均分：以如下形式顯示：課程ID，課程name，最高分，最低分，平均分，及格率，中等率，優(yōu)良率，優(yōu)秀率

--及格為>=60，中等為：70-80，優(yōu)良為：80-90，優(yōu)秀為：>=90

--方法1

select m.C# [課程編號], m.Cname [課程名稱],

max(n.score) [最高分],

min(n.score) [最低分],

cast(avg(n.score) as decimal(18,2)) [平均分],

cast((select count(1) from SC where C# = m.C# and score >= 60)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [及格率(%)],

cast((select count(1) from SC where C# = m.C# and score >= 70 and score < 80 )*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [中等率(%)],

cast((select count(1) from SC where C# = m.C# and score >= 80 and score < 90 )*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [優(yōu)良率(%)],

cast((select count(1) from SC where C# = m.C# and score >= 90)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [優(yōu)秀率(%)]

from Course m , SC n

where m.C# = n.C#

group by m.C# , m.Cname

order by m.C#

--方法2

select m.C# [課程編號], m.Cname [課程名稱],

(select max(score) from SC where C# = m.C#) [最高分],

(select min(score) from SC where C# = m.C#) [最低分],

(select cast(avg(score) as decimal(18,2)) from SC where C# = m.C#) [平均分],

cast((select count(1) from SC where C# = m.C# and score >= 60)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [及格率(%)],

cast((select count(1) from SC where C# = m.C# and score >= 70 and score < 80 )*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [中等率(%)],

cast((select count(1) from SC where C# = m.C# and score >= 80 and score < 90 )*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [優(yōu)良率(%)],

cast((select count(1) from SC where C# = m.C# and score >= 90)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [優(yōu)秀率(%)]

from Course m

order by m.C#

--19、按各科成績進(jìn)行排序，并顯示排名

--19.1 sql 2000用子查詢完成

--Score重復(fù)時保留名次空缺

select t.* , px = (select count(1) from SC where C# = t.C# and score > t.score) + 1 from sc t order by t.c# , px

--Score重復(fù)時合并名次

select t.* , px = (select count(distinct score) from SC where C# = t.C# and score >= t.score) from sc t order by t.c# , px

--19.2 sql 2005用rank,DENSE_RANK完成

--Score重復(fù)時保留名次空缺(rank完成)

select t.* , px = rank() over(partition by c# order by score desc) from sc t order by t.C# , px

--Score重復(fù)時合并名次(DENSE_RANK完成)

select t.* , px = DENSE_RANK() over(partition by c# order by score desc) from sc t order by t.C# , px

--20、查詢學(xué)生的總成績并進(jìn)行排名

--20.1 查詢學(xué)生的總成績

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

order by [總成績] desc

--20.2 查詢學(xué)生的總成績并進(jìn)行排名，sql 2000用子查詢完成，分總分重復(fù)時保留名次空缺和不保留名次空缺兩種。

select t1.* , px = (select count(1) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t2 where 總成績 > t1.總成績) + 1 from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t1

order by px

select t1.* , px = (select count(distinct 總成績) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t2 where 總成績 >= t1.總成績) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t1

order by px

--20.3 查詢學(xué)生的總成績并進(jìn)行排名，sql 2005用rank,DENSE_RANK完成，分總分重復(fù)時保留名次空缺和不保留名次空缺兩種。

select t.* , px = rank() over(order by [總成績] desc) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t

order by px

select t.* , px = DENSE_RANK() over(order by [總成績] desc) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(sum(score),0) [總成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t

order by px

--21、查詢不同老師所教不同課程平均分從高到低顯示

select m.T# , m.Tname , cast(avg(o.score) as decimal(18,2)) avg_score

from Teacher m , Course n , SC o

where m.T# = n.T# and n.C# = o.C#

group by m.T# , m.Tname

order by avg_score desc

--22、查詢所有課程的成績第2名到第3名的學(xué)生信息及該課程成績

--22.1 sql 2000用子查詢完成

--Score重復(fù)時保留名次空缺

select * from (select t.* , px = (select count(1) from SC where C# = t.C# and score > t.score) + 1 from sc t) m where px between 2 and 3 order by m.c# , m.px

--Score重復(fù)時合并名次

select * from (select t.* , px = (select count(distinct score) from SC where C# = t.C# and score >= t.score) from sc t) m where px between 2 and 3 order by m.c# , m.px

--22.2 sql 2005用rank,DENSE_RANK完成

--Score重復(fù)時保留名次空缺(rank完成)

select * from (select t.* , px = rank() over(partition by c# order by score desc) from sc t) m where px between 2 and 3 order by m.C# , m.px

--Score重復(fù)時合并名次(DENSE_RANK完成)

select * from (select t.* , px = DENSE_RANK() over(partition by c# order by score desc) from sc t) m where px between 2 and 3 order by m.C# , m.px

--23、統(tǒng)計各科成績各分?jǐn)?shù)段人數(shù)：課程編號,課程名稱,[100-85],[85-70],[70-60],[0-60]及所占百分比

--23.1 統(tǒng)計各科成績各分?jǐn)?shù)段人數(shù)：課程編號,課程名稱,[100-85],[85-70],[70-60],[0-60]

--橫向顯示

select Course.C# [課程編號] , Cname as [課程名稱] ,

sum(case when score >= 85 then 1 else 0 end) [85-100],

sum(case when score >= 70 and score < 85 then 1 else 0 end) [70-85],

sum(case when score >= 60 and score < 70 then 1 else 0 end) [60-70],

sum(case when score < 60 then 1 else 0 end) [0-60]

from sc , Course

where SC.C# = Course.C#

group by Course.C# , Course.Cname

order by Course.C#

--縱向顯示1(顯示存在的分?jǐn)?shù)段)

select m.C# [課程編號] , m.Cname [課程名稱] , 分?jǐn)?shù)段 = (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end) ,

count(1) 數(shù)量

from Course m , sc n

where m.C# = n.C#

group by m.C# , m.Cname , (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end)

order by m.C# , m.Cname , 分?jǐn)?shù)段

--縱向顯示2(顯示存在的分?jǐn)?shù)段，不存在的分?jǐn)?shù)段用0顯示)

select m.C# [課程編號] , m.Cname [課程名稱] , 分?jǐn)?shù)段 = (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end) ,

count(1) 數(shù)量

from Course m , sc n

where m.C# = n.C#

group by all m.C# , m.Cname , (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end)

order by m.C# , m.Cname , 分?jǐn)?shù)段

--23.2 統(tǒng)計各科成績各分?jǐn)?shù)段人數(shù)：課程編號,課程名稱,[100-85],[85-70],[70-60],[<60]及所占百分比

--橫向顯示

select m.C# 課程編號, m.Cname 課程名稱,

(select count(1) from SC where C# = m.C# and score < 60) [0-60],

cast((select count(1) from SC where C# = m.C# and score < 60)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [百分比(%)],

(select count(1) from SC where C# = m.C# and score >= 60 and score < 70) [60-70],

cast((select count(1) from SC where C# = m.C# and score >= 60 and score < 70)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [百分比(%)],

(select count(1) from SC where C# = m.C# and score >= 70 and score < 85) [70-85],

cast((select count(1) from SC where C# = m.C# and score >= 70 and score < 85)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [百分比(%)],

(select count(1) from SC where C# = m.C# and score >= 85) [85-100],

cast((select count(1) from SC where C# = m.C# and score >= 85)*100.0 / (select count(1) from SC where C# = m.C#) as decimal(18,2)) [百分比(%)]

from Course m

order by m.C#

--縱向顯示1(顯示存在的分?jǐn)?shù)段)

select m.C# [課程編號] , m.Cname [課程名稱] , 分?jǐn)?shù)段 = (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end) ,

count(1) 數(shù)量 ,

cast(count(1) * 100.0 / (select count(1) from sc where C# = m.C#) as decimal(18,2)) [百分比(%)]

from Course m , sc n

where m.C# = n.C#

group by m.C# , m.Cname , (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end)

order by m.C# , m.Cname , 分?jǐn)?shù)段

--縱向顯示2(顯示存在的分?jǐn)?shù)段，不存在的分?jǐn)?shù)段用0顯示)

select m.C# [課程編號] , m.Cname [課程名稱] , 分?jǐn)?shù)段 = (

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end) ,

count(1) 數(shù)量 ,

cast(count(1) * 100.0 / (select count(1) from sc where C# = m.C#) as decimal(18,2)) [百分比(%)]

from Course m , sc n

where m.C# = n.C#

group by all m.C# , m.Cname , (//包含所有的分組結(jié)果

case when n.score >= 85 then '85-100'

when n.score >= 70 and n.score < 85 then '70-85'

when n.score >= 60 and n.score < 70 then '60-70'

else '0-60'

end)

order by m.C# , m.Cname , 分?jǐn)?shù)段

--24、查詢學(xué)生平均成績及其名次

--24.1 查詢學(xué)生的平均成績并進(jìn)行排名，sql 2000用子查詢完成，分平均成績重復(fù)時保留名次空缺和不保留名次空缺兩種。

select t1.* , px = (select count(1) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(cast(avg(score) as decimal(18,2)),0) [平均成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t2 where 平均成績 > t1.平均成績) + 1 from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(cast(avg(score) as decimal(18,2)),0) [平均成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t1

order by px

select t1.* , px = (select count(distinct 平均成績) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(cast(avg(score) as decimal(18,2)),0) [平均成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t2 where 平均成績 >= t1.平均成績) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(cast(avg(score) as decimal(18,2)),0) [平均成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t1

order by px

--24.2 查詢學(xué)生的平均成績并進(jìn)行排名，sql 2005用rank,DENSE_RANK完成，分平均成績重復(fù)時保留名次空缺和不保留名次空缺兩種。

select t.* , px = rank() over(order by [平均成績] desc) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(cast(avg(score) as decimal(18,2)),0) [平均成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t

order by px

select t.* , px = DENSE_RANK() over(order by [平均成績] desc) from

(

select m.S# [學(xué)生編號] ,

m.Sname [學(xué)生姓名] ,

isnull(cast(avg(score) as decimal(18,2)),0) [平均成績]

from Student m left join SC n on m.S# = n.S#

group by m.S# , m.Sname

) t

order by px

--25、查詢各科成績前三名的記錄

--25.1 分?jǐn)?shù)重復(fù)時保留名次空缺

select m.* , n.C# , n.score from Student m, SC n where m.S# = n.S# and n.score in

(select top 3 score from sc where C# = n.C# order by score desc) order by n.C# , n.score desc

--25.2 分?jǐn)?shù)重復(fù)時不保留名次空缺，合并名次

--sql 2000用子查詢實現(xiàn)

select * from (select t.* , px = (select count(distinct score) from SC where C# = t.C# and score >= t.score) from sc t) m where px between 1 and 3 order by m.c# , m.px

--sql 2005用DENSE_RANK實現(xiàn)

select * from (select t.* , px = DENSE_RANK() over(partition by c# order by score desc) from sc t) m where px between 1 and 3 order by m.C# , m.px

--26、查詢每門課程被選修的學(xué)生數(shù)

select c# , count(S#)[學(xué)生數(shù)] from sc group by C#

--27、查詢出只有兩門課程的全部學(xué)生的學(xué)號和姓名

select Student.S# , Student.Sname

from Student , SC

where Student.S# = SC.S#

group by Student.S# , Student.Sname

having count(SC.C#) = 2

order by Student.S#

--28、查詢男生、女生人數(shù)

select count(Ssex) as 男生人數(shù) from Student where Ssex = N'男'

select count(Ssex) as 女生人數(shù) from Student where Ssex = N'女'

select sum(case when Ssex = N'男' then 1 else 0 end) [男生人數(shù)],sum(case when Ssex = N'女' then 1 else 0 end) [女生人數(shù)] from student

select case when Ssex = N'男' then N'男生人數(shù)' else N'女生人數(shù)' end [男女情況] , count(1) [人數(shù)] from student group by case when Ssex = N'男' then N'男生人數(shù)' else N'女生人數(shù)' end

--29、查詢名字中含有"風(fēng)"字的學(xué)生信息

select * from student where sname like N'%風(fēng)%'

select * from student where charindex(N'風(fēng)' , sname) > 0

--30、查詢同名同性學(xué)生名單，并統(tǒng)計同名人數(shù)

select Sname [學(xué)生姓名], count(*) [人數(shù)] from Student group by Sname having count(*) > 1

--31、查詢1990年出生的學(xué)生名單(注：Student表中Sage列的類型是datetime)

select * from Student where year(sage) = 1990

select * from Student where datediff(yy,sage,'1990-01-01') = 0

select * from Student where datepart(yy,sage) = 1990

select * from Student where convert(varchar(4),sage,120) = '1990'

--32、查詢每門課程的平均成績，結(jié)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 m.C# , m.Cname , cast(avg(n.score) as decimal(18,2)) avg_score

from Course m, SC n

where m.C# = n.C#

group by m.C# , m.Cname

order by avg_score desc, m.C# asc

--33、查詢平均成績大于等于85的所有學(xué)生的學(xué)號、姓名和平均成績

select a.S# , a.Sname , cast(avg(b.score) as decimal(18,2)) avg_score

from Student a , sc b

where a.S# = b.S#

group by a.S# , a.Sname

having cast(avg(b.score) as decimal(18,2)) >= 85

order by a.S#

--34、查詢課程名稱為"數(shù)學(xué)"，且分?jǐn)?shù)低于60的學(xué)生姓名和分?jǐn)?shù)

select sname , score

from Student , SC , Course

where SC.S# = Student.S# and SC.C# = Course.C# and Course.Cname = N'數(shù)學(xué)' and score < 60

--35、查詢所有學(xué)生的課程及分?jǐn)?shù)情況；

select Student.* , Course.Cname , SC.C# , SC.score

from Student, SC , Course

where Student.S# = SC.S# and SC.C# = Course.C#

order by Student.S# , SC.C#

--36、查詢?nèi)魏我婚T課程成績在70分以上的姓名、課程名稱和分?jǐn)?shù)；

select Student.* , Course.Cname , SC.C# , SC.score

from Student, SC , Course

where Student.S# = SC.S# and SC.C# = Course.C# and SC.score >= 70

order by Student.S# , SC.C#

--37、查詢不及格的課程

select Student.* , Course.Cname , SC.C# , SC.score

from Student, SC , Course

where Student.S# = SC.S# and SC.C# = Course.C# and SC.score < 60

order by Student.S# , SC.C#

--38、查詢課程編號為01且課程成績在80分以上的學(xué)生的學(xué)號和姓名；

select Student.* , Course.Cname , SC.C# , SC.score

from Student, SC , Course

where Student.S# = SC.S# and SC.C# = Course.C# and SC.C# = '01' and SC.score >= 80

order by Student.S# , SC.C#

--39、求每門課程的學(xué)生人數(shù)

select Course.C# , Course.Cname , count(*) [學(xué)生人數(shù)]

from Course , SC

where Course.C# = SC.C#

group by ?Course.C# , Course.Cname

order by Course.C# , Course.Cname

--40、查詢選修"張三"老師所授課程的學(xué)生中，成績最高的學(xué)生信息及其成績

--40.1 當(dāng)最高分只有一個時

select top 1 Student.* , Course.Cname , SC.C# , SC.score

from Student, SC , Course , Teacher

where Student.S# = SC.S# and SC.C# = Course.C# and Course.T# = Teacher.T# and Teacher.Tname = N'張三'

order by SC.score desc

--40.2 當(dāng)最高分出現(xiàn)多個時

select Student.* , Course.Cname , SC.C# , SC.score

from Student, SC , Course , Teacher

where Student.S# = SC.S# and SC.C# = Course.C# and Course.T# = Teacher.T# and Teacher.Tname = N'張三' and

SC.score = (select max(SC.score) from SC , Course , Teacher where SC.C# = Course.C# and Course.T# = Teacher.T# and Teacher.Tname = N'張三')

--41、查詢不同課程成績相同的學(xué)生的學(xué)生編號、課程編號、學(xué)生成績

--方法1

select m.* from SC m ,(select C# , score from SC group by C# , score having count(1) > 1) n

where m.C#= n.C# and m.score = n.score order by m.C# , m.score , m.S#

--方法2

select m.* from SC m where exists (select 1 from (select C# , score from SC group by C# , score having count(1) > 1) n

where m.C#= n.C# and m.score = n.score) order by m.C# , m.score , m.S#

--42、查詢每門功成績最好的前兩名

select t.* from sc t where score in (select top 2 score from sc where C# = T.C# order by score desc) order by t.C# , t.score desc

--43、統(tǒng)計每門課程的學(xué)生選修人數(shù)(超過5人的課程才統(tǒng)計)。要求輸出課程號和選修人數(shù)，查詢結(jié)果按人數(shù)降序排列，若人數(shù)相同，按課程號升序排列

select Course.C# , Course.Cname , count(*) [學(xué)生人數(shù)]

from Course , SC

where Course.C# = SC.C#

group by ?Course.C# , Course.Cname

having count(*) >= 5

order by [學(xué)生人數(shù)] desc , Course.C#

--44、檢索至少選修兩門課程的學(xué)生學(xué)號

select student.S# , student.Sname

from student , SC

where student.S# = SC.S#

group by student.S# , student.Sname

having count(1) >= 2

order by student.S#

--45、查詢選修了全部課程的學(xué)生信息

--方法1 根據(jù)數(shù)量來完成

select student.* from student where S# in

(select S# from sc group by S# having count(1) = (select count(1) from course))

--方法2 使用雙重否定來完成

select t.* from student t where t.S# not in

(

select distinct m.S# from

(

select S# , C# from student , course

) m where not exists (select 1 from sc n where n.S# = m.S# and n.C# = m.C#)

)

--方法3 使用雙重否定來完成

select t.* from student t where not exists(select 1 from

(

select distinct m.S# from

(

select S# , C# from student , course

) m where not exists (select 1 from sc n where n.S# = m.S# and n.C# = m.C#)

) k where k.S# = t.S#

)

--46、查詢各學(xué)生的年齡

--46.1 只按照年份來算

select * , datediff(yy , sage , getdate()) [年齡] from student

--46.2 按照出生日期來算，當(dāng)前月日 < 出生年月的月日則，年齡減一

select * , case when right(convert(varchar(10),getdate(),120),5) < right(convert(varchar(10),sage,120),5) then datediff(yy , sage , getdate()) - 1 else datediff(yy , sage , getdate()) end [年齡] from student

--47、查詢本周過生日的學(xué)生

select * from student where datediff(week,datename(yy,getdate()) + right(convert(varchar(10),sage,120),6),getdate()) = 0

--48、查詢下周過生日的學(xué)生

select * from student where datediff(week,datename(yy,getdate()) + right(convert(varchar(10),sage,120),6),getdate()) = -1

--49、查詢本月過生日的學(xué)生

select * from student where datediff(mm,datename(yy,getdate()) + right(convert(varchar(10),sage,120),6),getdate()) = 0

--50、查詢下月過生日的學(xué)生

select * from student where datediff(mm,datename(yy,getdate()) + right(convert(varchar(10),sage,120),6),getdate()) = -1

drop table ?Student,Course,Teacher,SC

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