SQL 增刪改查45道題

create database School
use School
go
create table Student  --1.學生表
(
    Sno varchar(20) not null primary key,--學號（主碼）
    Sname varchar(20) not null,--學生姓名
    Ssex varchar(20) not null,--學生性別
    Sbirthday datetime,--學生出生年月
    Class varchar(20),--學生所在班級
)
go
create table Teacher   --4.教師表
(
    Tno varchar(20) not null primary key,--教工編號（主）
    Tname varchar(20) not null,--教工姓名
    Tsex varchar(20) not null,--教工性別
    Tbirthday datetime,--教工出生年月
    Prof varchar(20),--職稱
    Depart varchar(20) not null,--教工所在部門
)
go
create table Course    --2.課程表
(
    Cno varchar(20) not null primary key,--課程號（主）
    Cname varchar(20) not null,--課程名稱
    Tno varchar(20) not null references Teacher(Tno),--教工編號（外）
)
go
create table Score    --3.成績表
(
    Sno varchar(20) not null references Student(Sno),--學號（外）
    Cno varchar(20) not null references Course(Cno),--課程號（外）
    Degree decimal(4,1),--成績
)
alter table Score add constraint Pk_Score primary key (Sno,Cno) --添加兩個主鍵

--學生信息
insert into Student values('108','曾華','男','1977-09-01','95033')
insert into Student(Sno,Sname,Ssex,Sbirthday,Class)values('105','匡明','男','1975-10-02','95031')
insert into Student values('107','王麗','女','1976-01-23','95033')
insert into Student values('101','李軍','男','1976-02-20','95033')
insert into Student values('109','王芳','女','1975-02-10','95031')
insert into Student values('103','陸君','男','1974-06-03','95031')
--職工信息
insert into Teacher values('804','李誠','男','1958-12-02','副教授','計算機系')
insert into Teacher values('856','張旭','男','1969-03-12','講師','電子工程系')
insert into Teacher values('825','王萍','女','1972-05-05','助教','計算機系')
insert into Teacher values('831','劉冰','女','1977-08-14','助教','電子工程系')
--課程
insert into Course values('3-105','計算機導論','825')
insert into Course values('3-245','操作系統','804')
insert into Course values('6-166','數字電路','856')
insert into Course values('9-888','高等數學','831')
--成績
insert into Score values('103','3-245','86')
insert into Score values('105','3-245','75')
insert into Score values('109','3-245','68')
insert into Score values('103','3-105','92')
insert into Score values('105','3-105','88')
insert into Score values('109','3-105','76')
insert into Score values('101','3-105','64')
insert into Score values('107','3-105','91')
insert into Score values('108','3-105','78')
insert into Score values('101','6-166','85')
insert into Score values('107','6-166','79')
insert into Score values('108','6-166','81')
--1、 查詢Student表中的所有記錄的Sname、Ssex和Class列。
select Sname,Ssex,Class from Student
--2、 查詢教師所有的單位即不重復的Depart列。 
--去重 distinct
select distinct Depart from Teacher 
--3、 查詢Student表的所有記錄。
select * from Student
--4、 查詢Score表中成績在60到80之間的所有記錄。
--范圍查詢 比較運算符
select * from Score where Degree>=60 and Degree<=80  
--between...and...
select * from Score where Degree between 60 and 80
--5、 查詢Score表中成績為85，86或88的記錄。
select * from Score where Degree=85 or Degree=86 or Degree=88
--離散查詢
select * from Score where Degree in (85,86,88) 
--6、 查詢Student表中“95031”班或性別為“女”的同學記錄。
select * from Student where Class='95031' or Ssex='女'
--7、 以Class降序查詢Student表的所有記錄。
--排序order by  升序asc 降序desc
select * from Student order by Class desc 
--8、 以Cno升序、Degree降序查詢Score表的所有記錄。
select * from Score order by Cno asc,Degree desc 
--9、 查詢“95031”班的學生人數。
--個數count(*)
select Class,COUNT(*) from Student group by Class having Class=95031 
select count(*) from student where class='95031'
--10、 查詢Score表中的最高分的學生學號和課程號。（子查詢或者排序）
--子查詢
select Sno,Cno from Score where Degree=(select max(Degree) from Score)
--降序取第一條數據
select top 1 Sno,Cno from Score order by Degree desc
--11、 查詢每門課的平均成績。
--平均分用avg(列)
select Cno,AVG(Degree) as '平均分' from Score group by Cno
--12、查詢Score表中至少有5名學生選修的並以3開頭的課程的平均分數。
--模糊查詢 like  分組 group by...having...
select Cno,AVG(Degree) as '平均分' from Score group by Cno having COUNT(Cno)>=5 and Cno like'3%'
select avg(degree) from score where cno like'3%' group by cno having count(*)>=5
--13、查詢分數大於70，小於90的Sno列。
--范圍查詢
select Sno from Score where Degree>70 and Degree<90
select Sno from Score where Degree between 70 and 90
--14、查詢所有學生的Sname、Cno和Degree列。
--連接查詢
select Student.Sname,Cno,Degree from Student,Score where Score.Sno=Student.Sno
--join...on...
select Sname,Cno,Degree from Student join Score on Student.Sno=Score.Sno
--15、查詢所有學生的Sno、Cname和Degree列。
select Sno,Cname,Degree from Course,Score where Score.Cno=Course.Cno
select Sno,Cname,Degree from Score join Course on Score.Cno=Course.Cno
--16、查詢所有學生的Sname、Cname和Degree列。
select Sname,Cname,Degree from Student,Course,Score where Student.Sno=Score.Sno and Course.Cno=Score.Cno
--17、 查詢“95033”班學生的平均分。
select Class='95033',AVG(degree) as '平均分' from Score join Student on Score.Sno=Student.Sno and Class='95033'
select avg(degree) from score where sno in(select sno from student where class='95033')
--18、 假設使用如下命令建立了一個grade表：
create table grade
(
    low  int,
    upp  int,
    rank  varchar(1)
)
insert into grade values(90,100,'A')
insert into grade values(80,89,'B')
insert into grade values(70,79,'C')
insert into grade values(60,69,'D')
insert into grade values(0,59,'E')
--現查詢所有同學的Sno、Cno和rank列。
select Sno,Cno,Degree,rank from grade join Score on Score.Degree  between low and upp
select sno,cno,rank from score,grade where degree between low and upp
--19、查詢選修“3-105”課程的成績高於“109”號同學成績的所有同學的記錄。
select * from Score where Degree>(select Degree from Score where Cno='3-105' and Sno='109') and Cno='3-105'
select * from Student join Score on Student.Sno=Score.Sno where Cno='3-105' and Degree>(select Degree from Score where Cno='3-105' and Sno='109')
--20、查詢score中選學多門課程的同學中分數為非最高分成績的記錄。
--反向查詢沒有出現過得值not in
select * from score a where sno in (select sno from score group by sno having count(*)>1) and degree <(select max(degree) from score b where b.cno=a.cno)
select * from Score where Sno in(select Sno from Score group by Sno having COUNT(Sno)>=2 )and Degree not in( select max(Degree) from Score group by Cno)
--21、查詢成績高於學號為“109”、課程號為“3-105”的成績的所有記錄。
select * from Score where Degree>(select Max(Degree) from Score where Sno='109')and Cno='3-105'
--22、查詢和學號為108的同學同年出生的所有學生的Sno、Sname和Sbirthday列。
--獲取年year(時間日期)
select Sno,Sname,Sbirthday from Student where YEAR(Sbirthday)=(select year(Sbirthday) from Student where Sno='108')
select Sno,Sname,Sbirthday from Student where year(Sbirthday)=(select year(Sbirthday) from Student where Sno='107')
--23、查詢“張旭“教師任課的學生成績。
select * from Score where Cno=(select Cno from Course where Tno=(select Tno from Teacher where Tname='張旭'))
--24、查詢選修某課程的同學人數多於5人的教師姓名。
select Tname from Teacher where Tno=(select Tno from Course where Cno=(select Cno from Score group by Cno having COUNT(Cno)>5))
select Teacher.Tno,Tname,Cno,Cname from Teacher join Course on Teacher.Tno=Course.Tno where Tname in (select Tname from Teacher where Tno in (select Tno from Course where Cno in (select Cno from Score group by Cno having count(Cno)>=5)))
--25、查詢95033班和95031班全體學生的記錄。
--與 or
select * from Student where Class='95033' or Class='95031'
--26、查詢存在有85分以上成績的課程Cno.
select distinct Cno from Score where Degree>85 
--27、查詢出“計算機系“教師所教課程的成績表。
select * from Score where Cno in (select Cno from Course where Tno in (select Tno from Teacher where Depart='計算機系'))
--28、查詢“計算機系”與“電子工程系“depart不同職稱prof的教師的Tname和Prof。
--聯合查詢
select tname,prof from teacher where depart='計算機系' and prof not in(select prof from teacher where depart='電子工程系')
union
select tname,prof from teacher where depart='電子工程系' and prof not in(select prof from teacher where depart='計算機系')
--相關子查詢
select Tname,prof from Teacher a where Prof not in (select Prof from Teacher b where a.Depart!=b.Depart)
--29、查詢選修編號為“3-105“課程且成績至少高於選修編號為“3-245”的同學的Cno、Sno和Degree,並按Degree從高到低次序排序。
select Cno,Sno,Degree from Score where Cno='3-105' and Degree >(select MAX(Degree) from Score where Cno='3-245') order by Degree desc 
--any 列表中任意一個相當於max
select * from score where cno='3-105' and degree>any(select degree from score where cno='3-245')
--30、查詢選修編號為“3-105”且成績高於選修編號為“3-245”課程的同學的Cno、Sno和Degree.
select * from Score where Cno='3-105' and Degree >(select MAX(Degree) from Score where Cno='3-245')
--31、查詢所有教師和同學的name、sex和birthday.
--聯合查詢
select Tname as name,Tsex as sex,Tbirthday as birthday from Teacher
union
select Sname,Ssex,Sbirthday from Student
--32、查詢所有“女”教師和“女”同學的name、sex和birthday.
--聯合查詢 條件查詢
select Tname as name,Tsex as sex,Tbirthday as birthday from Teacher where Tsex='女'
union
select Sname,Ssex,Sbirthday from Student where Ssex='女'
--33、查詢成績比該課程平均成績低的同學的成績表。
select * from Score a where Degree <(select AVG(Degree) from Score b where a.Cno=b.Cno) 
--34、查詢所有任課教師的Tname和Depart.
select Tname,Depart from Teacher 
--35、查詢所有未講課的教師的Tname和Depart. 
select Tname,Depart from Teacher where Tno not in (select Tno from Course where Cno in (select distinct Cno from Score))
--36、查詢至少有2名男生的班號。
select Class from Student where Ssex='男' group by Class having COUNT(*)>1
--37、查詢Student表中不姓“王”的同學記錄。
--不像not like
select * from Student where Sname not like'王%'
select * from Student where Sname not in (select Sname from Student where Sname like '王%')
--38、查詢Student表中每個學生的姓名和年齡。
--當前系統時間getdate(),獲取數據庫時間sysdatetime()
select Sname as '姓名',YEAR(GETDATE())-YEAR(Sbirthday) as '年齡' from Student
--39、查詢Student表中最大和最小的Sbirthday日期值。
--最大值max（列）最小值min（列）
select MAX(Sbirthday) as '大',MIN(Sbirthday) as '小' from Student
--40、以班號和年齡從大到小的順序查詢Student表中的全部記錄。
--多個條件進行排序用，連接
select * from Student order by Class desc,Sbirthday desc
--41、查詢“男”教師及其所上的課程。
select Teacher.Tno,Tname,Tsex,Cno,Cname from Teacher,Course where Teacher.Tno=Course.Tno and Tsex='男'
--42、查詢最高分同學的Sno、Cno和Degree列。
select * from Score where Degree=(select MAX(Degree) from Score)
--43、查詢和“李軍”同性別的所有同學的Sname.
select Sname from Student where Ssex=(select Ssex from Student where Sname='李軍')
--44、查詢和“李軍”同性別並同班的同學Sname.
select Sname from Student where Ssex in (select Ssex from Student where Sname='李軍') and Class in (select Class from Student where Sname='李軍')
--45、查詢所有選修“計算機導論”課程的“男”同學的成績表。
select * from Score where Cno in (select Cno from Course where Cname='計算機導論') and Sno in (select Sno from Student where Ssex='男')