学了很多东西,感受本身的sql语句仍是很很差,从基础学起吧。sql
来一段sql脚本:sqlserver
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:server
-- 1.查询Student表中的全部记录的Sname、Ssex和Class列。 SELECT Sname,Ssex,Class FROM student --2.查询教师全部的单位即不重复的Depart列。 SELECT DISTINCT depart FROM teacher --3.查询Score表中成绩在60到80之间的全部记录。 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”的同窗记录。 select * from student where [class] ='95031' and Ssex='女' --6.以Class降序查询Student表的全部记录。 select * from student order by class desc --7.以Cno升序、Degree降序查询Score表的全部记录。 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.查询全部学生的Sname、Cno和Degree列。 select sname,cno,degree from score join student on score.sno = student.sno --14.查询全部学生的Sno、Cname和Degree列。 select sno,cname,degree from score join course on score.cno=course.cno --15.查询全部学生的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”号同窗成绩的全部同窗的记录。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窗中分数为非最高分红绩的记录。 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”的成绩的全部记录。 select * from Score where DEGREE>(select DEGREE from Score where Sno='109' and Sno='3-105') --20 查询和学号为108的同窗同年出生的全部学生的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.询选修某课程的同窗人数多于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“不一样职称的教师的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')unionselect 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”的同窗的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 做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')----2八、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同窗的Cno、Sno和Degree.select * from score where cno='3-105' and degree>any(select degree from score where cno='3-245')--2九、 查询全部教师和同窗的name、sex和birthday.select sname,ssex,sbirthday from studentunionselect tname,tsex,tbirthday from teacher--30、查询全部“女”教师和“女”同窗的name、sex和birthday.select sname,ssex,sbirthday from student where ssex='女'unionselect tname,tsex,tbirthday from teacher where tsex='女'--3一、 查询成绩比该课程平均成绩低的同窗的成绩表。select * from score a where degree<(select avg(degree) from score b where b.cno=a.cno)--3二、 查询全部任课教师的Tname和Depart.select tname,depart from teacher where tno in(select tno from course where cno in (select distinct cno from score))--33 、 查询全部未讲课的教师的Tname和Depart.select tname,depart from teacher where tno not in(select tno from course where cno in (select distinct cno from score))--3四、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--3五、查询Student表中不姓“王”的同窗记录。select * from student where sname not like '王%'--3六、查询Student表中每一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--3七、查询Student表中最大和最小的Sbirthday日期值。select max(sbirthday),min(sbirthday) from student--3八、以班号和年龄从大到小的顺序查询Student表中的所有记录。select * from student order by class desc,sbirthday asc--3九、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、查询最高分同窗的Sno、Cno和Degree列。select * from score where degree = (select max(degree) from score)select top 1 * from score order by degree desc--4一、查询和“李军”同性别的全部同窗的Sname.select sname from student where ssex=(select ssex from student where sname='李军')--4二、查询和“李军”同性别并同班的同窗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')--4三、查询全部选修“计算机导论”课程的“男”同窗的成绩表。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')