一、创建表并初始化数据
1、表说明
student(学生表)、teacher(教师表)、course(课程表)、sc(分数表)
2、创建表
//学生表
create table student( sno varchar2(10) primary key, sname varchar2(20), sage number(2), ssex varchar2(5) );
//教师表 create table teacher( tno varchar2(10) primary key, tname varchar2(20) );
//课程表 create table course( cno varchar2(10), cname varchar2(20), tno varchar2(20), constraint pk_course primary key (cno,tno) );
//分数表 create table sc( sno varchar2(10), cno varchar2(10), score number(4,2), constraint pk_sc primary key (sno,cno) );
3、插入初始化数据
/*******初始化学生表的数据******/ insert into student values (\'s001\',\'张三\',23,\'男\'); insert into student values (\'s002\',\'李四\',23,\'男\'); insert into student values (\'s003\',\'吴鹏\',25,\'男\'); insert into student values (\'s004\',\'琴沁\',20,\'女\'); insert into student values (\'s005\',\'王丽\',20,\'女\'); insert into student values (\'s006\',\'李波\',21,\'男\'); insert into student values (\'s007\',\'刘玉\',21,\'男\'); insert into student values (\'s008\',\'萧蓉\',21,\'女\'); insert into student values (\'s009\',\'陈萧晓\',23,\'女\'); insert into student values (\'s010\',\'陈美\',22,\'女\'); commit;
/******************初始化教师表***********************/ insert into teacher values (\'t001\', \'刘阳\'); insert into teacher values (\'t002\', \'谌燕\'); insert into teacher values (\'t003\', \'胡明星\'); commit;
/***************初始化课程表****************************/ insert into course values (\'c001\',\'J2SE\',\'t002\'); insert into course values (\'c002\',\'Java Web\',\'t002\'); insert into course values (\'c003\',\'SSH\',\'t001\'); insert into course values (\'c004\',\'Oracle\',\'t001\'); insert into course values (\'c005\',\'SQL SERVER 2005\',\'t003\'); insert into course values (\'c006\',\'C#\',\'t003\'); insert into course values (\'c007\',\'JavaScript\',\'t002\'); insert into course values (\'c008\',\'DIV+CSS\',\'t001\'); insert into course values (\'c009\',\'PHP\',\'t003\'); insert into course values (\'c010\',\'EJB3.0\',\'t002\'); commit;
/***************初始化成绩表***********************/ insert into sc values (\'s001\',\'c001\',78.9); insert into sc values (\'s002\',\'c001\',80.9); insert into sc values (\'s003\',\'c001\',81.9); insert into sc values (\'s004\',\'c001\',60.9); insert into sc values (\'s001\',\'c002\',82.9); insert into sc values (\'s002\',\'c002\',72.9); insert into sc values (\'s003\',\'c002\',81.9); insert into sc values (\'s001\',\'c003\',\'59\'); commit;
二、SQL语句
1、查询“c001”课程比“c002”课程成绩高的所有学生的学号； select a.* from (select * from sc a where a.cno=\'c001\') a, (select * from sc b where b.cno=\'c002\') b where a.sno=b.sno and a.score > b.score; 或 select * from sc a where a.cno=\'c001\' and exists(select * from sc b where b.cno=\'c002\' and a.score>b.score and a.sno = b.sno) ****************************************************************** 2、查询平均成绩大于60 分的同学的学号和平均成绩； select sno,avg(score) from sc group by sno having avg(score)>60; ****************************************************************** 3、查询所有同学的学号、姓名、选课数、总成绩； select a.*,s.sname from (select sno,sum(score),count(cno) from sc group by sno) a ,student s where a.sno=s.sno ****************************************************************** 4、查询姓“刘”的老师的个数； select count(*) from teacher where tname like \'刘%\'; ****************************************************************** 5、查询没学过“谌燕”老师课的同学的学号、姓名； select a.sno,a.sname from student a where a.sno not in ( select distinct s.sno from sc s, ( select c.* from course c , (select tno from teacher t where tname=\'谌燕\') t where c.tno=t.tno ) b where s.cno = b.cno ) 或 select * from student st where st.sno not in ( select distinct sno from sc s join course c on s.cno=c.cno join teacher t on c.tno=t.tno where tname=\'谌燕\' ) ****************************************************************** 6、查询学过“c001”并且也学过编号“c002”课程的同学的学号、姓名； select st.* from sc a join sc b on a.sno=b.sno join student st on st.sno=a.sno where a.cno=\'c001\' and b.cno=\'c002\' and st.sno=a.sno; ****************************************************************** 7、查询学过“谌燕”老师所教的所有课的同学的学号、姓名； select st.* from student st join sc s on st.sno=s.sno join course c on s.cno=c.cno join teacher t on c.tno=t.tno where t.tname=\'谌燕\' ****************************************************************** 8、查询课程编号“c002”的成绩比课程编号“c001”课程低的所有同学的学号、姓名； select * from student st join sc a on st.sno=a.sno join sc b on st.sno=b.sno where a.cno=\'c002\' and b.cno=\'c001\' and a.score < b.score ****************************************************************** 9、查询所有课程成绩小于60 分的同学的学号、姓名； select st.*,s.score from student st join sc s on st.sno=s.sno join course c on s.cno=c.cno where s.score <60 ****************************************************************** 10、查询没有学全所有课的同学的学号、姓名； select stu.sno,stu.sname,count(sc.cno) from student stu left join sc on stu.sno=sc.sno group by stu.sno,stu.sname having count(sc.cno)<(select count(distinct cno)from course) 或 select * from student where sno in ( select sno from ( select stu.sno,c.cno from student stu cross join course c minus select sno,cno from sc ) ) ****************************************************************** 11、查询至少有一门课与学号为“s001”的同学所学相同的同学的学号和姓名； select st.* from student st, (select distinct a.sno from (select * from sc) a, (select * from sc where sc.sno=\'s001\') b where a.cno=b.cno ) h where st.sno=h.sno and st.sno<>\'s001\' ****************************************************************** 12、查询至少学过学号为“s001”同学所有一门课的其他同学学号和姓名； select * from sc left join student st on st.sno=sc.sno where sc.sno<>\'s001\' and sc.cno in (select cno from sc where sno=\'s001\') ****************************************************************** 13、把“SC”表中“谌燕”老师教的课的成绩都更改为此课程的平均成绩； update sc c set score= ( select avg(c.score) from course a,teacher b where a.tno=b.tno and b.tname=\'谌燕\' and a.cno=c.cno group by c.cno ) where cno in( select cno from course a,teacher b where a.tno=b.tno and b.tname=\'谌燕\') ****************************************************************** 14、查询和“s001”号的同学学习的课程完全相同的其他同学学号和姓名； select* from sc where sno<>\'s001\' minus ( select* from sc minus select * from sc where sno=\'s001\') ****************************************************************** 15、删除学习“谌燕”老师课的SC 表记录； delete from sc where sc.cno in ( select cno from course c left join teacher t on c.tno=t.tno where t.tname=\'谌燕\' ) ****************************************************************** 16、向SC 表中插入一些记录，这些记录要求符合以下条件：没有上过编号“c002”课程的同学学号、“c002”号课的平均成绩； insert into sc (sno,cno,score) select distinct st.sno,sc.cno,(select avg(score)from sc where cno=\'c002\') from student st,sc where not exists (select * from sc where cno=\'c002\' and sc.sno=st.sno) and sc.cno=\'c002\'; ****************************************************************** 17、查询各科成绩最高和最低的分：以如下形式显示：课程ID，最高分，最低分 select cno ,max(score),min(score) from sc group by cno; ****************************************************************** 18、按各科平均成绩从低到高和及格率的百分数从高到低顺序 select cno,avg(score),sum(case when score>=60 then 1 else 0 end)/count(*) as 及格率 from sc group by cno order by avg(score) , 及格率 desc ****************************************************************** 19、查询不同老师所教不同课程平均分从高到低显示 select max(t.tno),max(t.tname),max(c.cno),max(c.cname),c.cno,avg(score) from sc , course c,teacher t where sc.cno=c.cno and c.tno=t.tno group by c.cno order by avg(score) desc ****************************************************************** 20、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60] select sc.cno,c.cname, sum(case when score between 85 and 100 then 1 else 0 end) AS "[100-85]", sum(case when score between 70 and 85 then 1 else 0 end) AS "[85-70]", sum(case when score between 60 and 70 then 1 else 0 end) AS "[70-60]", sum(case when score <60 then 1 else 0 end) AS "[<60]" from sc, course c where sc.cno=c.cno group by sc.cno ,c.cname; ****************************************************************** 21、查询各科成绩前三名的记录:(不考虑成绩并列情况) select * from (select sno,cno,score,row_number()over(partition by cno order by score desc) rn from sc) where rn<4 ****************************************************************** 22、查询每门课程被选修的学生数 select cno,count(sno)from sc group by cno; ****************************************************************** 23、查询出只选修了一门课程的全部学生的学号和姓名 select sc.sno,st.sname,count(cno) from student st left join sc on sc.sno=st.sno group by st.sname,sc.sno having count(cno)=1; ****************************************************************** 24、查询男生、女生人数 select ssex,count(*)from student group by ssex; ****************************************************************** 25、查询姓“张”的学生名单 select * from student where sname like \'张%\'; ****************************************************************** 26、查询同名同性学生名单，并统计同名人数 select sname,count(*)from student group by sname having count(*)>1; ****************************************************************** 27、1981 年出生的学生名单(注：Student 表中Sage 列的类型是number) select sno,sname,sage,ssex from student t where to_char(sysdate,\'yyyy\')-sage =1988 ****************************************************************** 28、查询每门课程的平均成绩，结果按平均成绩升序排列，平均成绩相同时，按课程号降序排列 select cno,avg(score) from sc group by cno order by avg(score)asc,cno desc; ****************************************************************** 29、查询平均成绩大于85 的所有学生的学号、姓名和平均成绩 select st.sno,st.sname,avg(score) from student st left join sc on sc.sno=st.sno group by st.sno,st.sname having avg(score)>85; ****************************************************************** 30、查询课程名称为“数据库”，且分数低于60 的学生姓名和分数 select sname,score from student st,sc,course c where st.sno=sc.sno and sc.cno=c.cno and c.cname=\'Oracle\' and sc.score<60 ****************************************************************** 31、查询所有学生的选课情况； select st.sno,st.sname,c.cname from student st,sc,course c where sc.sno=st.sno and sc.cno=c.cno; ****************************************************************** 32、查询任何一门课程成绩在70 分以上的姓名、课程名称和分数； select st.sname,c.cname,sc.score from student st,sc,course c where sc.sno=st.sno and sc.cno=c.cno and sc.score>70 ****************************************************************** 33、查询不及格的课程，并按课程号从大到小排列 select sc.sno,c.cname,sc.score from sc,course c where sc.cno=c.cno and sc.score<60 order by sc.cno desc; ****************************************************************** 34、查询课程编号为c001 且课程成绩在80 分以上的学生的学号和姓名； select st.sno,st.sname,sc.score from sc,student st where sc.sno=st.sno and cno=\'c001\' and score>80; ****************************************************************** 35、求选了课程的学生人数 select count(distinct sno) from sc; ****************************************************************** 36、查询选修“谌燕”老师所授课程的学生中，成绩最高的学生姓名及其成绩 select st.sname,score from student st,sc ,course c,teacher t where st.sno=sc.sno and sc.cno=c.cno and c.tno=t.tno and t.tname=\'谌燕\' and sc.score= (select max(score)from sc where sc.cno=c.cno) ****************************************************************** 37、查询各个课程及相应的选修人数 select cno,count(sno) from sc group by cno; ****************************************************************** 38、查询不同课程成绩相同的学生的学号、课程号、学生成绩 select a.* from sc a ,sc b where a.score=b.score and a.cno<>b.cno ****************************************************************** 39、查询每门功课成绩最好的前两名 select * from ( select sno,cno,score,row_number()over(partition by cno order by score desc) my_rn from sc t ) where my_rn<=2 ****************************************************************** 40、统计每门课程的学生选修人数（超过10 人的课程才统计）。要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列 select cno,count(sno) from sc group by cno having count(sno)>10 order by count(sno) desc,cno asc; ****************************************************************** 41、检索至少选修两门课程的学生学号 select sno from sc group by sno having count(cno)>1; 或 select sno from sc group by sno having count(sno)>1; ****************************************************************** 42、查询全部学生都选修的课程的课程号和课程名 select distinct(c.cno),c.cname from course c ,sc where sc.cno=c.cno 或 select cno,cname from course c where c.cno in (select cno from sc group by cno) ****************************************************************** 43、查询没学过“谌燕”老师讲授的任一门课程的学生姓名 select st.sname from student st where st.sno not in (select distinct sc.sno from sc,course c,teacher t where sc.cno=c.cno and c.tno=t.tno and t.tname=\'谌燕\') ****************************************************************** 44、查询两门以上不及格课程的同学的学号及其平均成绩 select sno,avg(score)from sc where sno in ( select sno from sc where sc.score<60 group by sno having count(sno)>1 ) group by sno ****************************************************************** 45、检索“c004”课程分数小于60，按分数降序排列的同学学号 select sno from sc where cno=\'c004\' and score<90 order by score desc; ****************************************************************** 46、删除“s002”同学的“c001”课程的成绩 delete from sc where sno=\'s002\' and cno=\'c001\';