转载于:https://blog.csdn.net/tu451953337/article/details/45147757
题目来源于http://blog.csdn.net/lifetragedy/article/details/9935699,由于原文题目中的数据在我自己建的DB里没有数据,所以解答中的条件可能是符合我DB的条件,而不是符合题目的条件。但解答应该符合题目的意思要求。但是文中的解答肯能会有错误,但都是经过我DB中实际跑过的。欢迎指出错误。
select * from t_student 学生表
select * from t_course 课程表
select * from t_sc 学生成绩表
select * from t_teacher 老师表
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--http://blog.csdn.net/lifetragedy/article/details/9935699
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--create table t_student(stuid number(10,2) primary key,name varchar2(100), age number(3,0), sex char(1));
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--create table t_course(cid number(10,2) primary key, name varchar2(100), teacherid number(10, 2));
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--alter table t_course
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--add constraint tcourse_fk foreign key (teacherid) references t_teacher(tid);
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--create table t_sc(stuid number(10, 2), cid number(10,2), score number(10,2));
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--alter table t_sc
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--add constraint t_sc_pk primary key (stuid, cid);
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--alter table t_sc
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--add constraint t_sc_stuid_fk foreign key (stuid) references t_student(stuid);
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--alter table t_sc
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--add constraint t_sc_cid_fk foreign key (cid) references t_course(cid);
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--create table t_teacher(tid number(10,2) primary key, tname varchar2(100));
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/*
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select * from t_student for update;
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select * from t_course for update;
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select * from t_sc for update;
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select * from t_teacher for update;
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*/
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--查询“1”课程比“2”课程成绩高的所有学生的学号
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select a.stuid
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from ( select * from t_sc s where s.cid = 1) a,
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( select * from t_sc s where s.cid = 2) b
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where a.stuid = b.stuid
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and a.score > b.score;
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/*
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select a.S#
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from (select s#, score from SC where C# = '001') a,
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(select s#, score from SC where C# = '002')
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where a.score > b.score
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and a.s# = b.s#;
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*/
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--2、查询平均成绩大于80分的同学的学号和平均成绩;
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select stuid, avg(score) from t_sc group by stuid having avg(score)> 80;
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--3、查询所有同学的学号、姓名、选课数、总成绩;
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select s.stuid, s.name, c.xks, c.zcj
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from t_student s left outer join
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( select stuid, count(cid) xks, sum(score) zcj
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from t_sc
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group by stuid) c
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on s.stuid = c.stuid;
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select s.stuid, s.name, count(c.cid), sum(c.score)
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from t_student s
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left Outer join t_sc c
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on s.stuid = c.stuid
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group by s.stuid, s.name;
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--4、查询姓“李”的老师的个数;
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select count(tid) from t_teacher where tname like '李%';
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--5、查询没学过“叶平”老师课的同学的学号、姓名;
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select s.stuid,s.name from t_student s, t_course c, t_teacher t, t_sc sc where s.stuid=sc.stuid and c.cid=sc.cid and c.teacherid=t.tid and t.tname!= '叶平';
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select Student.S#, Student.Sname
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from Student
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where S# not in
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( select distinct (SC.S#) from SC,
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Course,
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Teacher where SC.C# = Course.C# and Teacher.T# = Course.T# andTeacher.Tname = '叶平');
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--6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名;
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select s.stuid,s.name from t_student s, t_sc c where c.cid= 1 and s.stuid=c.stuid and exists ( select * from t_sc sc where sc.stuid=s.stuid and sc.cid= 2);
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-- select Student.S#,Student.Sname fromStudent,SC where Student.S#=SC.S# andSC.C#='001'and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');
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--7、查询学过“叶平”老师所教的所有课的同学的学号、姓名;
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select s.stuid,s.name from t_student s, t_sc sc where s.stuid = sc.stuid and sc.cid in(
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select c.cid from t_teacher t, t_course c where t.tid=c.teacherid and t.tname= 'Mr.kay');
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select S#, Sname
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from Student
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where S# in
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( select S#
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from SC, Course, Teacher
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where SC.C# = Course.C# andTeacher.T# = Course.T#
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and Teacher.Tname = '叶平'
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group by S#
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having count(SC.C#) = ( select count(C#) from Course,
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Teacher where Teacher.T# = Course.T# and Tname = '叶平'));
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--8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名;
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Select S#, Sname
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from ( select Student.S#,
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Student.Sname,
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score,
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( select score
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from SC SC_2
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where SC_2.S# = Student.S# and SC_2.C# = '002') score2
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from Student, SC
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where Student.S# = SC.S# andC# = '001') S_2
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where score2 < score;
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--9、查询所有课程成绩小于60分的同学的学号、姓名;
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select s.stuid, s.name from t_student s where s.stuid not in ( select sc.stuid from t_student s, t_sc sc where sc.score>= 60 and s.stuid=sc.stuid);
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select s.stuid, s.name from t_student s where not exists ( select * from t_sc sc where sc.stuid=s.stuid and sc.score>= 60);
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--10、查询没有学全所有课的同学的学号、姓名;
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select s.stuid, s.name from t_student s,t_sc sc where s.stuid=sc.stuid group by s.stuid,s.name having count(sc.cid) != ( select count(cid) from t_course);
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select Student.S#, Student.Sname
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from Student, SC whereStudent.S# = SC.S#
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group by Student.S#, Student.Sname
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having count(C#) < ( select count(C#) from Course);
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--11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名;
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select distinct s.stuid,s.name from t_student s, t_sc sc where s.stuid=sc.stuid and s.stuid!= 1 and sc.cid in ( select cid from t_sc where stuid= 1)
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--select s.stuid,s.name from t_Student s, t_SC sc where s.stuid=SC.Stuid and sc.cid in (select Cid from t_SC where stuid='1');
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--13、把“t_SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩;
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update t_sc sc1 set sc1.score =
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( select avg(score) from t_sc group by cid having cid in ( select cid from t_teacher t, t_course c where t.tid=c.teacherid and t.tname= 'Mr.mao') and cid=sc1.cid);
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/*
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update t_sc sc_1
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set sc_1.score =
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(select avg(sc_2.score) from t_sc sc_2 where sc_2.cid = sc_1.cid)
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from t_course,
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t_teacher
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where t_course.Cid = t_sc.cid and t_course.tid = t_teacher.tid
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and t_teacher.tname = 'Mr.mao');
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*/
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select * from t_sc sc, t_course c, t_teacher t where sc.cid=c.cid and c.teacherid=t.tid and t.tname= 'Mr.mao'
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--14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名;
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select * from t_sc where stuid in(
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select stuid
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from t_sc
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group by stuid
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having count(*) = ( select count(*) from t_sc where stuid = 6)
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)
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and cid in ( select cid from t_sc where stuid= 6);
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--15、删除学习“叶平”老师课的SC表记录
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delete t_sc where cid in(
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select cid from t_course c, t_teacher t where c.teacherid=t.tid and t.tname= 'Mr.mao');
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--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“5”课程的同学学号、2号课的平均成绩;
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insert into t_sc
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select stuid, '5' cid, ( select avg(score) from t_sc sc where sc.cid= 2) score
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from t_student s where not exists
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( select * from t_sc sc where sc.cid= 5 and sc.stuid=s.stuid);
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--17、按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩,按
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--如下形式显示: 学生ID,,数据库,企业管理,英语,有效课程数,有效平均分
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select t.stuid,
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max( case t.cname when 'Chinese' then t.score end) Chinese,
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max( case t.cname when 'Math' then t.score end) Math,
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max( case t.cname when 'English' then t.score end) English,
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round( avg(t.score), 2) avgscore,
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count(t.cid) kcs
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from ( select s.stuid, s.name stuname, sc.cid, sc.score, c.name cname
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from t_student s, t_sc sc, t_course c
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where s.stuid = sc.stuid
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and sc.cid = c.cid
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and c.name in ( 'Chinese', 'Math', 'English')) t
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group by t.stuid
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order by avgscore desc;
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/*
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select sc.stuid,
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(select score from t_sc where cid=1 and stuid=sc.stuid) Chinese,
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(select score from t_sc where cid=2 and stuid=sc.stuid) Math,
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(select score from t_sc where cid=3 and stuid=sc.stuid) English,
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round(avg(sc.score),2) avgscore,
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count(c.cid) kcs
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from t_sc sc, t_course c where sc.cid=c.cid and c.name in ('Chinese', 'Math', 'English')
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group by sc.stuid
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order by avgscore desc;
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*/
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--18、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
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select cid, max(score) maxscore, min(score) minscore from t_sc group by cid order by cid;
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/*
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SELECT L.Cid As 课程ID, L.score AS 最高分, R.score AS 最低分
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FROM t_SC L, t_SC R
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WHERE L.Cid = R.Cid
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and L.score = (SELECT MAX(IL.score)
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FROM t_SC IL, t_Student IM
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WHERE L.Cid = IL.Cid
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and IM.Stuid = IL.Stuid
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GROUP BY IL.Cid)
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AND R.Score =
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(SELECT MIN(IR.score) FROM t_SC IR WHERE R.Cid = IR.Cid GROUP BY IR.Cid);
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*/
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--19、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
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select sc.cid, ( select name from t_course where cid=sc.cid) cname,
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round( avg(sc.score), 2) avgscore,
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round(( select count(*) from t_sc where cid = sc.cid and score>= 70)/
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( select count(*) from t_sc where cid = sc.cid)* 100, 2)|| '%' jgl
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from t_sc sc
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group by sc.cid
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order by avgscore, jgl desc;
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/*
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SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS平均成绩
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,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分数
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FROM SC T,Course
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where t.C#=course.C#
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GROUP BY t.C#
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ORDER BY 100* SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
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*/
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--20、查询如下课程平均成绩和及格率的百分数(用"1行"显示):
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--企业管理(001),马克思(002),OO&UML (003),数据库(004)
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select * from t_sc sc group by sc.cid
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select sc.cid, ( select name from t_course where cid=sc.cid) cname,
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case sc.cid when 1 then round( avg(sc.score), 2) end chinese_avgscore,
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case sc.cid when 1 then
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round(( select count(*) from t_sc where cid = sc.cid and score>= 70)/
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( select count(*) from t_sc where cid = sc.cid)* 100, 2)|| '%' end chinese_jgl
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from t_sc sc
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group by sc.cid
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--21、查询不同老师所教不同课程平均分从高到低显示
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select sc.cid,
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round( avg(sc.score), 2) avg_score,
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c.name,
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t.tname
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from t_sc sc, t_course c, t_teacher t
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where sc.cid=c.cid and t.tid=c.teacherid
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group by sc.cid, c.name, t.tname
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order by avg_score desc;
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--22、查询如下语文成绩第 2 名到第 5 名的学生成绩单:
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--[学生ID],[学生姓名],语文成绩, 排名
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select * from (
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select t.*, rownum tn from (
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select s.stuid, s.name,
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min( case c.name when 'Chinese' then sc.score end) chinese_score
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from t_student s, t_sc sc, t_course c
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where s.stuid = sc.stuid
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and sc.cid = c.cid
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group by s.stuid, s.name
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order by chinese_score desc) t where rownum <= 5) where tn> 1
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--23、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]
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select sc.cid, c.name,
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( select count(*) from t_sc where cid=sc.cid and score>= 85 and score<= 100) a,
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( select count(*) from t_sc where cid=sc.cid and score>= 70 and score< 85) b,
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( select count(*) from t_sc where cid=sc.cid and score>= 60 and score< 70) c,
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( select count(*) from t_sc where cid=sc.cid and score< 60) d
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from t_sc sc, t_course c
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where sc.cid = c.cid
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group by sc.cid, c.name;
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/*
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SELECT SC.Cid as 课程ID, c.name as 课程名称
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,SUM(CASE WHEN sc.score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS a
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,SUM(CASE WHEN sc.score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS b
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,SUM(CASE WHEN sc.score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS c
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,SUM(CASE WHEN sc.score < 60 THEN 1 ELSE 0 END) AS d
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FROM t_SC sc,t_Course c
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where SC.Cid=C.Cid
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GROUP BY SC.Cid,c.name;
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*/
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--24、查询学生平均成绩及其名次
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select t.*, rownum rn from (
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select s.stuid, s.name, avg(sc.score) avg_score from t_student s, t_sc sc where s.stuid=sc.stuid
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group by s.stuid, s.name
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order by avg_score desc) t;
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select t.*, row_number() over( order by avg_score desc) pm from (
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select s.stuid, s.name, avg(sc.score) avg_score
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from t_student s, t_sc sc where s.stuid=sc.stuid
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group by s.stuid, s.name
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) t;
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--25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
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select * from (
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select sc.cid, c.name, sc.score, row_number() over( partition by sc.cid,c.name order by sc.score desc) pm
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from t_sc sc, t_course c where sc.cid=c.cid ) where pm <= 3;
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/*
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SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数
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FROM SC t1
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WHERE score IN (SELECT TOP 3 score
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FROM SC
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WHERE t1.C#= C#
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ORDER BY score DESC
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)
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ORDER BY t1.C#;
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*/
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--26、查询每门课程被选修的学生数
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select cid, count(*) rs, ( select name from t_course where cid=t_sc.cid) cname from t_sc group by cid;
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--27、查询出只选修了3门课程的全部学生的学号和姓名
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select sc.stuid, s.name from t_sc sc, t_student s where sc.stuid = s.stuid group by sc.stuid,s.name having count(*) = 3;
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-
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--28、查询男生、女生人数
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select case when sex= '1' then 'Man' else 'Woman' end sex, count(*) rs from t_student group by sex;
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--29、查询姓“张”的学生名单
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select * from t_student where name like 'w%';
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--30、查询同名同性学生名单,并统计同名人数
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select name, count(*) rs from t_student group by name having count(*)> 1;
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--31、1981年出生的学生名单(注:Student表中Sage列的类型是datetime)
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select to_char( sysdate, 'yyyy') year from dual;
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--32、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
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select cid, round( avg(score), 2) avg_score from t_sc group by cid order by avg_score, cid desc;
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--33、查询平均成绩大于85的所有学生的学号、姓名和平均成绩
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select s.stuid, s.name, round( avg(sc.score), 2) avg_score from t_student s, t_sc sc where s.stuid=sc.stuid group by s.stuid, s.name having avg(sc.score)> 80;
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--34、查询课程名称为“数据库”,且分数低于60的学生姓名和分数
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select s.stuid, s.name stuname, sc.score from t_student s, t_sc sc, t_course c where s.stuid=sc.stuid and sc.cid=c.cid and c.name= 'Computer' and sc.score< 70;
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--35、查询所有学生的选课情况
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select s.stuid, s.name stuname, c.cid, c.name coursename from t_student s, t_sc sc, t_course c where s.stuid=sc.stuid and sc.cid=c.cid;
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--36、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
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select s.stuid, s.name stuname, c.cid, c.name coursename, sc.score from t_student s, t_sc sc, t_course c where s.stuid=sc.stuid and sc.cid=c.cid and sc.score> 70;
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--37、查询不及格的课程,并按课程号从大到小排列
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select c.cid, c.name from t_sc sc, t_course c where sc.cid=c.cid group by c.cid,c.name,sc.score having sc.score< 70 order by c.cid desc;
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--38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名;
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select s.stuid, s.name, sc.score from t_student s,t_sc sc where s.stuid=sc.stuid and sc.cid= 3 and sc.score> 80;
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--39、求选了课程的学生人数
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select count(*) rs from ( select stuid from t_sc group by stuid);
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--40、查询选修“叶平”老师所授课程的学生中,成绩最高的学生姓名及其成绩
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select s.stuid, s.name stuname, t.max_score from t_student s, t_sc sc,
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( select c.cid, max(sc.score) max_score from t_sc sc, t_course c, t_teacher t where sc.cid=c.cid and c.teacherid=t.tid
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and t.tname= 'Mr.mao' group by c.cid) t
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where s.stuid=sc.stuid and sc.cid=t.cid and sc.score=t.max_score;
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/*
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select S.name stuname, sc.score
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from t_Student s, t_SC sc, t_Course C, t_Teacher t
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where S.Stuid = SC.Stuid
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and SC.Cid = C.Cid
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and C.Teacherid = T.tid
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and T.Tname = 'Mr.mao'
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and SC.score = (select max(score) from t_SC where Cid = C.Cid);*/
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--41、查询各个课程及相应的选修人数
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select cid, count(*) rs from t_sc group by cid order by cid;
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--42、查询不同课程成绩相同的学生的学号、课程号、学生成绩
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select * from t_sc sc where exists ( select * from t_sc where stuid!=sc.stuid and cid!=sc.cid and score=sc.score);
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select distinct A.Stuid,B.score from t_SC A ,t_SC B where A.Score=B.Score and A.Cid <>B.Cid ;
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--43、查询每门功成绩最好的前两名
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select * from ( select stuid, cid ,score, row_number() over( partition by cid order by score desc) pm from t_sc) where pm< 3;
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/*
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SELECT t1.S# as 学生ID, t1.C# as 课程ID, Score as 分数
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FROM SC t1
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WHERE score IN
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(SELECT TOP 2 score FROM SC WHERE t1.C# = C# ORDER BY score DESC)
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ORDER BY t1.C#;
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*/
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--44、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,
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--查询结果按人数降序排列,查询结果按人数降序排列,若人数相同,按课程号升序排列
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select cid, count(*) rs from t_sc group by cid having count(*) > 5 order by rs desc, cid;
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--45、检索至少选修两门课程的学生学号
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select stuid , count(*) from t_sc group by stuid having count(*) > 2;
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-
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--46、查询全部学生都选修的课程的课程号和课程名
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select c.cid, c.name from t_course c where exists (
-
select cid, count(*) rs from t_sc where cid=c.cid group by cid having count(*) = ( select count(*) from t_student)
-
);
-
-
--47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
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select * from t_student where stuid not in(
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select s.stuid from t_student s, t_sc sc where s.stuid=sc.stuid and sc.cid in ( select cid from t_course c, t_teacher t where c.teacherid=t.tid and t.tname= 'Mr.zhu'));
-
-
select * from t_Student s where s.stuid not in ( select sc.stuid from t_Course c,t_Teacher t,t_SC sc where c.teacherid=T.Tid and SC.Cid=c.Cid and t.Tname= 'Mr.zhu');
-
-
-
--48、查询1门以上不及格课程的同学的学号及其平均成绩
-
select stuid, avg(score) avg_score from t_sc group by stuid having stuid in(
-
select stuid from t_sc where score< 70 group by stuid having count(*) > 1);
-
-
select S#, avg( isnull(score, 0)) from SC where S# in ( select S# from SC where score < 60 group by S# having count(*)> 1) group by S#;
-
-
--49、检索“5”课程分数小于60,按分数降序排列的同学学号
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select stuid from t_sc where cid= 5 and score< 70 order by score desc;
-
-
--50、删除“002”同学的“001”课程的成绩
-
delete from t_sc where stuid= 2 and cid= 1;
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-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
题目来源于http://blog.csdn.net/lifetragedy/article/details/9935699,由于原文题目中的数据在我自己建的DB里没有数据,所以解答中的条件可能是符合我DB的条件,而不是符合题目的条件。但解答应该符合题目的意思要求。但是文中的解答肯能会有错误,但都是经过我DB中实际跑过的。欢迎指出错误。
select * from t_student 学生表
select * from t_course 课程表
select * from t_sc 学生成绩表
select * from t_teacher 老师表
-
--http://blog.csdn.net/lifetragedy/article/details/9935699
-
--create table t_student(stuid number(10,2) primary key,name varchar2(100), age number(3,0), sex char(1));
-
-
--create table t_course(cid number(10,2) primary key, name varchar2(100), teacherid number(10, 2));
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--alter table t_course
-
--add constraint tcourse_fk foreign key (teacherid) references t_teacher(tid);
-
-
--create table t_sc(stuid number(10, 2), cid number(10,2), score number(10,2));
-
--alter table t_sc
-
--add constraint t_sc_pk primary key (stuid, cid);
-
--alter table t_sc
-
--add constraint t_sc_stuid_fk foreign key (stuid) references t_student(stuid);
-
--alter table t_sc
-
--add constraint t_sc_cid_fk foreign key (cid) references t_course(cid);
-
-
--create table t_teacher(tid number(10,2) primary key, tname varchar2(100));
-
/*
-
select * from t_student for update;
-
select * from t_course for update;
-
select * from t_sc for update;
-
select * from t_teacher for update;
-
*/
-
-
--查询“1”课程比“2”课程成绩高的所有学生的学号
-
select a.stuid
-
from ( select * from t_sc s where s.cid = 1) a,
-
( select * from t_sc s where s.cid = 2) b
-
where a.stuid = b.stuid
-
and a.score > b.score;
-
/*
-
select a.S#
-
from (select s#, score from SC where C# = '001') a,
-
(select s#, score from SC where C# = '002')
-
where a.score > b.score
-
and a.s# = b.s#;
-
*/
-
--2、查询平均成绩大于80分的同学的学号和平均成绩;
-
select stuid, avg(score) from t_sc group by stuid having avg(score)> 80;
-
-
--3、查询所有同学的学号、姓名、选课数、总成绩;
-
select s.stuid, s.name, c.xks, c.zcj
-
from t_student s left outer join
-
( select stuid, count(cid) xks, sum(score) zcj
-
from t_sc
-
group by stuid) c
-
on s.stuid = c.stuid;
-
-
select s.stuid, s.name, count(c.cid), sum(c.score)
-
from t_student s
-
left Outer join t_sc c
-
on s.stuid = c.stuid
-
group by s.stuid, s.name;
-
--4、查询姓“李”的老师的个数;
-
select count(tid) from t_teacher where tname like '李%';
-
-
--5、查询没学过“叶平”老师课的同学的学号、姓名;
-
select s.stuid,s.name from t_student s, t_course c, t_teacher t, t_sc sc where s.stuid=sc.stuid and c.cid=sc.cid and c.teacherid=t.tid and t.tname!= '叶平';
-
-
select Student.S#, Student.Sname
-
from Student
-
where S# not in
-
( select distinct (SC.S#) from SC,
-
Course,
-
Teacher where SC.C# = Course.C# and Teacher.T# = Course.T# andTeacher.Tname = '叶平');
-
-
--6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名;
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select s.stuid,s.name from t_student s, t_sc c where c.cid= 1 and s.stuid=c.stuid and exists ( select * from t_sc sc where sc.stuid=s.stuid and sc.cid= 2);
-
-
-- select Student.S#,Student.Sname fromStudent,SC where Student.S#=SC.S# andSC.C#='001'and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');
-
-
--7、查询学过“叶平”老师所教的所有课的同学的学号、姓名;
-
select s.stuid,s.name from t_student s, t_sc sc where s.stuid = sc.stuid and sc.cid in(
-
select c.cid from t_teacher t, t_course c where t.tid=c.teacherid and t.tname= 'Mr.kay');
-
-
select S#, Sname
-
from Student
-
where S# in
-
( select S#
-
from SC, Course, Teacher
-
where SC.C# = Course.C# andTeacher.T# = Course.T#
-
and Teacher.Tname = '叶平'
-
group by S#
-
having count(SC.C#) = ( select count(C#) from Course,
-
Teacher where Teacher.T# = Course.T# and Tname = '叶平'));
-
-
--8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名;
-
Select S#, Sname
-
from ( select Student.S#,
-
Student.Sname,
-
score,
-
( select score
-
from SC SC_2
-
where SC_2.S# = Student.S# and SC_2.C# = '002') score2
-
from Student, SC
-
where Student.S# = SC.S# andC# = '001') S_2
-
where score2 < score;
-
-
--9、查询所有课程成绩小于60分的同学的学号、姓名;
-
select s.stuid, s.name from t_student s where s.stuid not in ( select sc.stuid from t_student s, t_sc sc where sc.score>= 60 and s.stuid=sc.stuid);
-
select s.stuid, s.name from t_student s where not exists ( select * from t_sc sc where sc.stuid=s.stuid and sc.score>= 60);
-
-
--10、查询没有学全所有课的同学的学号、姓名;
-
select s.stuid, s.name from t_student s,t_sc sc where s.stuid=sc.stuid group by s.stuid,s.name having count(sc.cid) != ( select count(cid) from t_course);
-
-
select Student.S#, Student.Sname
-
from Student, SC whereStudent.S# = SC.S#
-
group by Student.S#, Student.Sname
-
having count(C#) < ( select count(C#) from Course);
-
-
--11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名;
-
select distinct s.stuid,s.name from t_student s, t_sc sc where s.stuid=sc.stuid and s.stuid!= 1 and sc.cid in ( select cid from t_sc where stuid= 1)
-
--select s.stuid,s.name from t_Student s, t_SC sc where s.stuid=SC.Stuid and sc.cid in (select Cid from t_SC where stuid='1');
-
-
--13、把“t_SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩;
-
update t_sc sc1 set sc1.score =
-
( select avg(score) from t_sc group by cid having cid in ( select cid from t_teacher t, t_course c where t.tid=c.teacherid and t.tname= 'Mr.mao') and cid=sc1.cid);
-
/*
-
update t_sc sc_1
-
set sc_1.score =
-
(select avg(sc_2.score) from t_sc sc_2 where sc_2.cid = sc_1.cid)
-
from t_course,
-
t_teacher
-
where t_course.Cid = t_sc.cid and t_course.tid = t_teacher.tid
-
and t_teacher.tname = 'Mr.mao');
-
*/
-
select * from t_sc sc, t_course c, t_teacher t where sc.cid=c.cid and c.teacherid=t.tid and t.tname= 'Mr.mao'
-
-
-
--14、查询和“1002”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 t_sc where stuid in(
-
select stuid
-
from t_sc
-
group by stuid
-
having count(*) = ( select count(*) from t_sc where stuid = 6)
-
)
-
and cid in ( select cid from t_sc where stuid= 6);
-
-
-
--15、删除学习“叶平”老师课的SC表记录
-
delete t_sc where cid in(
-
select cid from t_course c, t_teacher t where c.teacherid=t.tid and t.tname= 'Mr.mao');
-
-
--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“5”课程的同学学号、2号课的平均成绩;
-
insert into t_sc
-
select stuid, '5' cid, ( select avg(score) from t_sc sc where sc.cid= 2) score
-
from t_student s where not exists
-
( select * from t_sc sc where sc.cid= 5 and sc.stuid=s.stuid);
-
-
--17、按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩,按
-
--如下形式显示: 学生ID,,数据库,企业管理,英语,有效课程数,有效平均分
-
-
select t.stuid,
-
max( case t.cname when 'Chinese' then t.score end) Chinese,
-
max( case t.cname when 'Math' then t.score end) Math,
-
max( case t.cname when 'English' then t.score end) English,
-
round( avg(t.score), 2) avgscore,
-
count(t.cid) kcs
-
from ( select s.stuid, s.name stuname, sc.cid, sc.score, c.name cname
-
from t_student s, t_sc sc, t_course c
-
where s.stuid = sc.stuid
-
and sc.cid = c.cid
-
and c.name in ( 'Chinese', 'Math', 'English')) t
-
group by t.stuid
-
order by avgscore desc;
-
/*
-
select sc.stuid,
-
(select score from t_sc where cid=1 and stuid=sc.stuid) Chinese,
-
(select score from t_sc where cid=2 and stuid=sc.stuid) Math,
-
(select score from t_sc where cid=3 and stuid=sc.stuid) English,
-
round(avg(sc.score),2) avgscore,
-
count(c.cid) kcs
-
from t_sc sc, t_course c where sc.cid=c.cid and c.name in ('Chinese', 'Math', 'English')
-
group by sc.stuid
-
order by avgscore desc;
-
*/
-
-
--18、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 cid, max(score) maxscore, min(score) minscore from t_sc group by cid order by cid;
-
/*
-
SELECT L.Cid As 课程ID, L.score AS 最高分, R.score AS 最低分
-
FROM t_SC L, t_SC R
-
WHERE L.Cid = R.Cid
-
and L.score = (SELECT MAX(IL.score)
-
FROM t_SC IL, t_Student IM
-
WHERE L.Cid = IL.Cid
-
and IM.Stuid = IL.Stuid
-
GROUP BY IL.Cid)
-
AND R.Score =
-
(SELECT MIN(IR.score) FROM t_SC IR WHERE R.Cid = IR.Cid GROUP BY IR.Cid);
-
*/
-
-
-
--19、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 sc.cid, ( select name from t_course where cid=sc.cid) cname,
-
round( avg(sc.score), 2) avgscore,
-
round(( select count(*) from t_sc where cid = sc.cid and score>= 70)/
-
( select count(*) from t_sc where cid = sc.cid)* 100, 2)|| '%' jgl
-
from t_sc sc
-
group by sc.cid
-
order by avgscore, jgl desc;
-
/*
-
SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS平均成绩
-
,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分数
-
FROM SC T,Course
-
where t.C#=course.C#
-
GROUP BY t.C#
-
ORDER BY 100* SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
-
*/
-
-
--20、查询如下课程平均成绩和及格率的百分数(用"1行"显示):
-
--企业管理(001),马克思(002),OO&UML (003),数据库(004)
-
select * from t_sc sc group by sc.cid
-
-
select sc.cid, ( select name from t_course where cid=sc.cid) cname,
-
case sc.cid when 1 then round( avg(sc.score), 2) end chinese_avgscore,
-
case sc.cid when 1 then
-
round(( select count(*) from t_sc where cid = sc.cid and score>= 70)/
-
( select count(*) from t_sc where cid = sc.cid)* 100, 2)|| '%' end chinese_jgl
-
from t_sc sc
-
group by sc.cid
-
-
-
--21、查询不同老师所教不同课程平均分从高到低显示
-
select sc.cid,
-
round( avg(sc.score), 2) avg_score,
-
c.name,
-
t.tname
-
from t_sc sc, t_course c, t_teacher t
-
where sc.cid=c.cid and t.tid=c.teacherid
-
group by sc.cid, c.name, t.tname
-
order by avg_score desc;
-
-
--22、查询如下语文成绩第 2 名到第 5 名的学生成绩单:
-
--[学生ID],[学生姓名],语文成绩, 排名
-
select * from (
-
select t.*, rownum tn from (
-
select s.stuid, s.name,
-
min( case c.name when 'Chinese' then sc.score end) chinese_score
-
from t_student s, t_sc sc, t_course c
-
where s.stuid = sc.stuid
-
and sc.cid = c.cid
-
group by s.stuid, s.name
-
order by chinese_score desc) t where rownum <= 5) where tn> 1
-
-
--23、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.cid, c.name,
-
( select count(*) from t_sc where cid=sc.cid and score>= 85 and score<= 100) a,
-
( select count(*) from t_sc where cid=sc.cid and score>= 70 and score< 85) b,
-
( select count(*) from t_sc where cid=sc.cid and score>= 60 and score< 70) c,
-
( select count(*) from t_sc where cid=sc.cid and score< 60) d
-
from t_sc sc, t_course c
-
where sc.cid = c.cid
-
group by sc.cid, c.name;
-
/*
-
SELECT SC.Cid as 课程ID, c.name as 课程名称
-
,SUM(CASE WHEN sc.score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS a
-
,SUM(CASE WHEN sc.score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS b
-
,SUM(CASE WHEN sc.score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS c
-
,SUM(CASE WHEN sc.score < 60 THEN 1 ELSE 0 END) AS d
-
FROM t_SC sc,t_Course c
-
where SC.Cid=C.Cid
-
GROUP BY SC.Cid,c.name;
-
*/
-
-
--24、查询学生平均成绩及其名次
-
select t.*, rownum rn from (
-
select s.stuid, s.name, avg(sc.score) avg_score from t_student s, t_sc sc where s.stuid=sc.stuid
-
group by s.stuid, s.name
-
order by avg_score desc) t;
-
-
select t.*, row_number() over( order by avg_score desc) pm from (
-
select s.stuid, s.name, avg(sc.score) avg_score
-
from t_student s, t_sc sc where s.stuid=sc.stuid
-
group by s.stuid, s.name
-
) t;
-
-
--25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
-
select * from (
-
select sc.cid, c.name, sc.score, row_number() over( partition by sc.cid,c.name order by sc.score desc) pm
-
from t_sc sc, t_course c where sc.cid=c.cid ) where pm <= 3;
-
-
/*
-
SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数
-
FROM SC t1
-
WHERE score IN (SELECT TOP 3 score
-
FROM SC
-
WHERE t1.C#= C#
-
ORDER BY score DESC
-
)
-
ORDER BY t1.C#;
-
*/
-
-
--26、查询每门课程被选修的学生数
-
select cid, count(*) rs, ( select name from t_course where cid=t_sc.cid) cname from t_sc group by cid;
-
-
--27、查询出只选修了3门课程的全部学生的学号和姓名
-
select sc.stuid, s.name from t_sc sc, t_student s where sc.stuid = s.stuid group by sc.stuid,s.name having count(*) = 3;
-
-
-
--28、查询男生、女生人数
-
select case when sex= '1' then 'Man' else 'Woman' end sex, count(*) rs from t_student group by sex;
-
-
--29、查询姓“张”的学生名单
-
select * from t_student where name like 'w%';
-
-
--30、查询同名同性学生名单,并统计同名人数
-
select name, count(*) rs from t_student group by name having count(*)> 1;
-
-
--31、1981年出生的学生名单(注:Student表中Sage列的类型是datetime)
-
select to_char( sysdate, 'yyyy') year from dual;
-
-
--32、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 cid, round( avg(score), 2) avg_score from t_sc group by cid order by avg_score, cid desc;
-
-
--33、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 s.stuid, s.name, round( avg(sc.score), 2) avg_score from t_student s, t_sc sc where s.stuid=sc.stuid group by s.stuid, s.name having avg(sc.score)> 80;
-
-
--34、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 s.stuid, s.name stuname, sc.score from t_student s, t_sc sc, t_course c where s.stuid=sc.stuid and sc.cid=c.cid and c.name= 'Computer' and sc.score< 70;
-
-
--35、查询所有学生的选课情况
-
select s.stuid, s.name stuname, c.cid, c.name coursename from t_student s, t_sc sc, t_course c where s.stuid=sc.stuid and sc.cid=c.cid;
-
-
--36、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 s.stuid, s.name stuname, c.cid, c.name coursename, sc.score from t_student s, t_sc sc, t_course c where s.stuid=sc.stuid and sc.cid=c.cid and sc.score> 70;
-
-
--37、查询不及格的课程,并按课程号从大到小排列
-
select c.cid, c.name from t_sc sc, t_course c where sc.cid=c.cid group by c.cid,c.name,sc.score having sc.score< 70 order by c.cid desc;
-
-
--38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名;
-
select s.stuid, s.name, sc.score from t_student s,t_sc sc where s.stuid=sc.stuid and sc.cid= 3 and sc.score> 80;
-
-
--39、求选了课程的学生人数
-
select count(*) rs from ( select stuid from t_sc group by stuid);
-
-
--40、查询选修“叶平”老师所授课程的学生中,成绩最高的学生姓名及其成绩
-
select s.stuid, s.name stuname, t.max_score from t_student s, t_sc sc,
-
( select c.cid, max(sc.score) max_score from t_sc sc, t_course c, t_teacher t where sc.cid=c.cid and c.teacherid=t.tid
-
and t.tname= 'Mr.mao' group by c.cid) t
-
where s.stuid=sc.stuid and sc.cid=t.cid and sc.score=t.max_score;
-
/*
-
select S.name stuname, sc.score
-
from t_Student s, t_SC sc, t_Course C, t_Teacher t
-
where S.Stuid = SC.Stuid
-
and SC.Cid = C.Cid
-
and C.Teacherid = T.tid
-
and T.Tname = 'Mr.mao'
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and SC.score = (select max(score) from t_SC where Cid = C.Cid);*/
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--41、查询各个课程及相应的选修人数
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select cid, count(*) rs from t_sc group by cid order by cid;
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--42、查询不同课程成绩相同的学生的学号、课程号、学生成绩
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select * from t_sc sc where exists ( select * from t_sc where stuid!=sc.stuid and cid!=sc.cid and score=sc.score);
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select distinct A.Stuid,B.score from t_SC A ,t_SC B where A.Score=B.Score and A.Cid <>B.Cid ;
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--43、查询每门功成绩最好的前两名
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select * from ( select stuid, cid ,score, row_number() over( partition by cid order by score desc) pm from t_sc) where pm< 3;
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/*
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SELECT t1.S# as 学生ID, t1.C# as 课程ID, Score as 分数
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FROM SC t1
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WHERE score IN
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(SELECT TOP 2 score FROM SC WHERE t1.C# = C# ORDER BY score DESC)
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ORDER BY t1.C#;
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*/
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--44、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,
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--查询结果按人数降序排列,查询结果按人数降序排列,若人数相同,按课程号升序排列
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select cid, count(*) rs from t_sc group by cid having count(*) > 5 order by rs desc, cid;
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--45、检索至少选修两门课程的学生学号
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select stuid , count(*) from t_sc group by stuid having count(*) > 2;
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--46、查询全部学生都选修的课程的课程号和课程名
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select c.cid, c.name from t_course c where exists (
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select cid, count(*) rs from t_sc where cid=c.cid group by cid having count(*) = ( select count(*) from t_student)
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);
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--47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
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select * from t_student where stuid not in(
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select s.stuid from t_student s, t_sc sc where s.stuid=sc.stuid and sc.cid in ( select cid from t_course c, t_teacher t where c.teacherid=t.tid and t.tname= 'Mr.zhu'));
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select * from t_Student s where s.stuid not in ( select sc.stuid from t_Course c,t_Teacher t,t_SC sc where c.teacherid=T.Tid and SC.Cid=c.Cid and t.Tname= 'Mr.zhu');
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--48、查询1门以上不及格课程的同学的学号及其平均成绩
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select stuid, avg(score) avg_score from t_sc group by stuid having stuid in(
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select stuid from t_sc where score< 70 group by stuid having count(*) > 1);
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select S#, avg( isnull(score, 0)) from SC where S# in ( select S# from SC where score < 60 group by S# having count(*)> 1) group by S#;
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--49、检索“5”课程分数小于60,按分数降序排列的同学学号
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select stuid from t_sc where cid= 5 and score< 70 order by score desc;
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--50、删除“002”同学的“001”课程的成绩
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delete from t_sc where stuid= 2 and cid= 1;
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