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  • SqlServer基础语句练习(一)

          学了不少东西,感觉自己的sql语句还是很不好,从基础学起吧。

        来一段sql脚本:

    create database tongji
    go
    use tongji
    go
    create table student
    (
    Sno varchar(20) not null primary key ,--学号
    Sname varchar(20) not null,--学生姓名
    Ssex varchar(20) not null, --学生性别
    Sbirthday datetime,--学生出生年月
    Class varchar(20)--学生所在班级
    )
    go
    create table teacher--老师
    (
    Tno varchar(20) not null primary key ,--教工编号(主码)
    Tname varchar(20) not null,--教工姓名
    Tsex varchar(20) not null, --教工性别
    Tbirthday datetime,--教工出生年月
    Prof varchar(20),--职称
    Depart varchar(20) not null--教工所在部门
    )
    go
    create table Course--课程
    (
    Cno varchar(20) not null primary key ,--课程号
    Cname varchar(20) not null,--课程名称
    Tno varchar(20) not null references teacher(Tno), --教工编号(外码)
    )
    go
    create table Score--分数
    (
    
    Sno varchar(20) not null references student(Sno), --学号(外码)
    Cno varchar(20) not null references Course(Cno), --课程号(外码)
    primary key(Sno,Cno),
    Degree Decimal(4,1),--成绩
    
    )
    

    开始写练习sql语句:

    -- 1.查询Student表中的所有记录的Sname、Ssex和Class列。
    SELECT Sname,Ssex,Class FROM student
    --2.查询教师所有的单位即不重复的Depart列。
    SELECT DISTINCT depart FROM teacher
    --3.查询Score表中成绩在60到80之间的所有记录。
    SELECT * FROM Score WHERE degree BETWEEN 60 AND 80
    
    --4.查询Score表中成绩为85,86或88的记录。
    select * from Score where degree in(85,86,88)
    
    --5.查询Student表中“95031”班或性别为“女”的同学记录。
    select * from student where [class]	='95031' and Ssex='女'
    --6.以Class降序查询Student表的所有记录。
    select * from student order by class desc
    --7.以Cno升序、Degree降序查询Score表的所有记录。
    select * from Score order by cno,degree desc
    
    --8.查询“95031”班的学生人数。
    select COUNT(*) from student where Class='95031'
    
    --9. 查询Score表中的最高分的学生学号和课程号。(子查询或者排序)
    select Sno,Cno from Score where degree=(select MAX(degree) from score)
    
    --10.查询每门课的平均成绩。
    select cno,AVG(degree) from Score group by Cno
    
    --11.查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。
    select AVG(degree) from Score where cno like'3%' group by Cno having  COUNT(*)>=5
    select Avg(degree) from Score group by Cno having COUNT(*)>=5 and Cno like'3%'
    
    --12.查询分数大于70,小于90的Sno列。
    select sno from Score where degree>70 and DEGREE<90
    
    --13.查询所有学生的Sname、Cno和Degree列。
    select sname,cno,degree from score join student on score.sno = student.sno
    
    --14.查询所有学生的Sno、Cname和Degree列。
    select sno,cname,degree from score join course on score.cno=course.cno
    
    --15.查询所有学生的Sname、Cname和Degree列。
    select sname,cname,degree from score join student on student.sno=score.sno join course on score.cno = course.cno
    select sname,cname,degree from score,student,course where student.sno=score.sno and score.cno = course.cno

    --16查询“95033”班学生的平均分。
    select AVG(degree) from Score where Sno in(select Sno from student where Class='95033')

    -- 17.查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。
    select * from Score where Cno='3-105' and DEGREE>(select DEGREE from Score where Sno='109' and Sno='3-105')
    select * from Score where Cno='3-105' and DEGREE>(select MAX(DEGREE) from Score where Sno='109')

     
     --18.查询score中选学多门课程的同学中分数为非最高分成绩的记录。
     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)

      --19查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
      select * from Score where DEGREE>(select DEGREE from Score where Sno='109' and Sno='3-105')


     --20 查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
      select * from student where YEAR(Sbirthday) =(select YEAR(Sbirthday) from student where Sno='108')

    --21. 查询“张旭“教师任课的学生成绩。
      select * from Score where cno in (select cno from Course where Tno in(select Tno from teacher where Tname='张旭'))

    --22.询选修某课程的同学人数多于5人的教师姓名。
      select tname from teacher where Tno in(select Tno from Course where Cno in(select Cno from Score group by Cno having COUNT(*)>=5))

    --23.查询95033班和95031班全体学生的记录。
      select * from student where Class in(95033,95031)

    --24.查询存在有85分以上成绩的课程Cno.
    select distinct cno from score where degree>85

    -25查询出“计算机系“教师所教课程的成绩表。
    select * from Score where Cno in(select Cno from Course where Tno in(select Tno from teacher where Depart='计算机系'))

    --26.--查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。
    select tname,prof from teacher where depart='计算机系' and prof not in(select prof from teacher where depart='电子工程系')union
    select  tname,prof from teacher where Depart='电子工程系' and Prof not in(select Prof from teacher where Depart='计算机系')

    select tname,Prof from teacher a where Prof not in(select Prof from teacher b where b.Depart!=a.Depart)

    --27.查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。
    --sqlserver 中 修改比较运算符:All 、Any、Some  其中Some 和Any 等价  作用于比较运算符和子查询之间 (https://technet.microsoft.com/zh-cn/library/ms187074(SQL.90).aspx)
    select * from Score where Cno='3-105' and DEGREE>any(select DEGREE from Score where Cno='3-245')

    ----28、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree.

    select * from score where cno='3-105' and degree>any(select degree from score where cno='3-245')

    --29、 查询所有教师和同学的name、sex和birthday.

    select sname,ssex,sbirthday from student
    union
    select tname,tsex,tbirthday from teacher

    --30、查询所有“女”教师和“女”同学的name、sex和birthday.

    select sname,ssex,sbirthday from student where ssex='女'
    union
    select tname,tsex,tbirthday from teacher where tsex='女'

    --31、 查询成绩比该课程平均成绩低的同学的成绩表。

    select * from score a where degree<(select avg(degree) from score b where b.cno=a.cno)

    --32、 查询所有任课教师的Tname和Depart.

    select tname,depart from teacher where tno in(select tno from course where cno in (select distinct cno from score))

    --33 、 查询所有未讲课的教师的Tname和Depart.

    select tname,depart from teacher where tno not in(select tno from course where cno in (select distinct cno from score))

    --34、查询至少有2名男生的班号。

    select class from student where ssex='男' group by class having count(*) >1

    --35、查询Student表中不姓“王”的同学记录。

    select * from student where sname not like '王%'

    --36、查询Student表中每个学生的姓名和年龄。 YEAR(GETDATE())-YEAR(Sbirthday) 表示你的年龄

    select sname,YEAR(getdate())-YEAR(sbirthday) from student

    --37、查询Student表中最大和最小的Sbirthday日期值。

    select max(sbirthday),min(sbirthday) from student

    --38、以班号和年龄从大到小的顺序查询Student表中的全部记录。

    select * from student order by class desc,sbirthday asc

    --39、查询“男”教师及其所上的课程。

    elect cname from course where tno in(select tno from teacher where tsex='男')

    select tname,cname from course,teacher where course.tno = teacher.tno and teacher.tsex='男'

    --40、查询最高分同学的Sno、Cno和Degree列。

    select * from score where degree = (select max(degree) from score)

    select top 1 * from score order by degree desc

    --41、查询和“李军”同性别的所有同学的Sname.

    select sname from student where ssex=(select ssex from student where sname='李军')

    --42、查询和“李军”同性别并同班的同学Sname.

    select sname from student where ssex=(select ssex from student where sname='李军') and class = (select class from student where sname='李军')

    --43、查询所有选修“计算机导论”课程的“男”同学的成绩表。

    select * from score where sno in(select sno from student where ssex='男') and cno in(select cno from course where cname='计算机导论')






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  • 原文地址:https://www.cnblogs.com/sunliyuan/p/5811431.html
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