表结构：
drop table student;
drop table course;
drop table score;
drop table teacher;
CREATE TABLE STUDENT
(SNO VARCHAR(30) NOT NULL,
SNAME VARCHAR(40) NOT NULL,
SSEX VARCHAR(20) NOT NULL,
SBIRTHDAY DATE,
CLASS NUMBER NOT NULL);
CREATE TABLE COURSE
(CNO VARCHAR(50) NOT NULL,
CNAME VARCHAR(100) NOT NULL,
TNO VARCHAR(100) NOT NULL);
CREATE TABLE SCORE
(SNO VARCHAR(30) NOT NULL,
CNO VARCHAR(50) NOT NULL,
DEGREE NUMBER NOT NULL);
CREATE TABLE TEACHER
(TNO VARCHAR(30) NOT NULL,
TNAME VARCHAR(40) NOT NULL,
TSEX VARCHAR(20) NOT NULL,
TBIRTHDAY DATE NOT NULL,
PROF VARCHAR(60),
DEPART VARCHAR(100) NOT NULL);
插入数据：
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,'曾华' ,'男' ,to_date('1977-09-01','yyyy-mm-dd'),95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,'匡明' ,'男' ,to_date('1975-10-02','yyyy-mm-dd'),95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,'王丽' ,'女' ,to_date('1976-01-23','yyyy-mm-dd'),95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,'李军' ,'男' ,to_date('1976-02-20','yyyy-mm-dd'),95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,'王芳' ,'女' ,to_date('1975-02-10','yyyy-mm-dd'),95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,'陆君' ,'男' ,to_date('1974-06-03','yyyy-mm-dd'),95031);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-105' ,'计算机导论',825);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-245' ,'操作系统' ,804);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('6-166' ,'数据电路' ,856);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('9-888' ,'高等数学' ,100);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-245',86);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-245',75);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-245',68);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-105',92);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-105',88);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-105',76);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'3-105',64);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'3-105',91);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'3-105',78);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'6-166',85);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'6-106',79);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'6-166',81);
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (804,'李诚','男',to_date('1958-12-02','yyyy-mm-dd'),'副教授','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (856,'张旭','男',to_date('1969-03-12','yyyy-mm-dd'),'讲师','电子工程系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (825,'王萍','女',to_date('1972-05-05','yyyy-mm-dd'),'助教','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (831,'刘冰','女',to_date('1977-08-14','yyyy-mm-dd'),'助教','电子工程系');
commit;
题目：
--1、 查询Student表中的所有记录的Sname、Ssex和Class列。
SELECT s.sname,s.ssex,s.class FROM student s ;
--2、 查询教师所有的单位即不重复的Depart列。
SELECT DISTINCT(t.depart) FROM teacher t;
--3、 查询Student表的所有记录。
SELECT s.* FROM student s;
--4、 查询Score表中成绩在60到80之间的所有记录。
SELECT s.* FROM score s WHERE s.degree BETWEEN 60 AND 80;
--5、 查询Score表中成绩为85，86或88的记录。,
SELECT s.* FROM score s WHERE s.degree IN(85,86,88);
--6、 查询Student表中“95031”班或性别为“女”的同学记录。
SELECT s.* FROM student s WHERE s.class='95031' OR s.ssex='女';
--7、 以Class降序查询Student表的所有记录。
SELECT s.* FROM student s ORDER BY s.class DESC;
--8、 以Cno升序、Degree降序查询Score表的所有记录。
SELECT s.* FROM score s ORDER BY s.cno ASC ,s.degree DESC;
--9、 查询“95031”班的学生人数。
SELECT COUNT(1) 学生人数 FROM student s WHERE s.class='95031'
--10、查询Score表中的最高分的学生学号和课程号。
SELECT s.sno,s.cno FROM score s WHERE s.degree=(SELECT MAX(s.degree) FROM score s);
--11、查询‘3-105’号课程的平均分。
SELECT AVG(s.degree) FROM score s WHERE s.cno='3-105';
--12、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 s.cno,AVG(s.degree) FROM score s WHERE s.cno LIKE('3%') GROUP BY s.cno HAVING COUNT(1) >=5;
--13、查询最低分大于70，最高分小于90的Sno列。
SELECT s.sno FROM score s WHERE s.degree BETWEEN 70 AND 90;
--14、查询所有学生的Sname、Cno和Degree列。
SELECT st.sname,sc.cno,sc.degree FROM student st ,score sc WHERE st.sno=sc.sno;
--15、查询所有学生的Sno、Cname和Degree列。
SELECT sc.sno,c.cname,sc.degree FROM score sc,course c WHERE sc.cno=c.cno;
--16、查询所有学生的Sname、Cname和Degree列。
SELECT (SELECT st.sname FROM student st WHERE st.sno=sc.sno),c.cname,sc.degree FROM score sc,course c WHERE sc.cno=c.cno;
--方法2
SELECT st.sname,c.cname,sc.degree FROM student st,score sc,course c WHERE st.sno=sc.sno AND c.cno=sc.cno;
--17、查询“95033”班所选课程的平均分。
SELECT st.class,AVG(sc.degree) FROM student st,score sc WHERE st.sno=sc.sno AND st.class='95033' GROUP BY st.class
--18、假设使用如下命令建立了一个grade表：
create table grade
(low number,
upp number,
rank char(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');
commit;
--现查询所有同学的Sno、Cno和rank列。
SELECT s.sno,s.cno,g.rank FROM score s,GRADE G WHERE s.degree>=g.low AND s.degree<=g.upp;
--19、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 st.* FROM student st,score sc WHERE st.sno=sc.sno AND sc.cno='3-105'
AND sc.degree>(SELECT sc.degree FROM score sc WHERE sc.sno='109' AND sc.cno='3-105' )
--20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录。(所有分数)
SELECT s.* FROM score s WHERE s.degree NOT IN (SELECT MAX(s.degree) FROM score s GROUP BY s.cno)
AND s.sno IN (SELECT s.sno FROM score s GROUP BY s.sno HAVING COUNT(1)>1)
--21、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 s WHERE s.degree>(SELECT s.degree FROM score s WHERE s.sno='109' AND s.cno='3-105')
--22、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 s.sno,s.sname,s.sbirthday FROM student s WHERE to_char(s.sbirthday,'yyyy')=
(SELECT to_char(s.sbirthday,'yyyy') FROM student s WHERE s.sno='108')
SELECT * FROM student s1,student s2 WHERE TO_char
--23、查询“张旭“教师任课的学生成绩。
SELECT t.tname, s.degree FROM course c,score s,teacher t WHERE c.tno=t.tno AND c.cno=s.cno AND t.tname='张旭'
--方法2
SELECT sc.* FROM score sc WHERE sc.cno IN
(SELECT c.cno FROM course c WHERE c.tno IN
(SELECT t.tno FROM teacher t WHERE t.tname='张旭'))
--24、查询选修某课程的同学人数多于5人的教师姓名。
SELECT t.tname FROM course c,score s,teacher t WHERE c.tno=t.tno AND c.cno=s.cno GROUP BY t.tname HAVING COUNT(1)>5
--方法2
SELECT t.tname FROM teacher t WHERE t.tno IN
(SELECT c.tno FROM course c WHERE c.cno IN
(SELECT sc.cno FROM score sc GROUP BY sc.cno HAVING COUNT(1)>5))
--25、查询95033班和95031班全体学生的记录。
SELECT s.* FROM student s WHERE s.class='95033'OR s.class='95031'
--26、查询存在有85分以上成绩的课程Cno.
SELECT DISTINCT s.cno FROM score s WHERE s.degree>'85'
--27、查询出“计算机系“教师所教课程的成绩表。
SELECT s.degree FROM score s,course c,teacher t WHERE s.cno=c.cno AND c.tno=t.tno AND t.depart='计算机系'
--28、查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。
SELECT t.tname,t.prof FROM teacher t WHERE t.depart='计算机系'
AND t.prof NOT IN(SELECT t.prof FROM teacher t WHERE t.depart='电子工程系')
--29、查询选修编号为“3-105“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。
SELECT s.cno,s.sno,s.degree FROM score s WHERE s.cno='3-105' AND
s.degree>ANY(SELECT s.degree FROM score s WHERE s.cno='3-245') ORDER BY s.degree DESC
--30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”的同学的Cno、Sno和Degree.
SELECT s.cno,s.sno,s.degree FROM score s WHERE s.cno='3-105' AND
s.degree>ALL(SELECT s.degree FROM score s WHERE s.cno='3-245')
--31、查询所有教师和同学的name、sex和birthday.
SELECT tname,tsex,tbirthday FROM teacher UNION SELECT sname,ssex,sbirthday FROM student;
--32、查询所有“女”教师和“女”同学的name、sex和birthday.
SELECT tname,tsex,tbirthday FROM teacher WHERE tsex='女'
UNION SELECT sname,ssex,sbirthday FROM student WHERE ssex='女';
--union：意思为联合，使用条件为两个表的列的类型和列数都要相同
--union all 与union 的区别在于union all 包含了重复的数据
--33、查询成绩比该课程平均成绩低的同学的成绩表。
Select a.* from score a where degree<( Select AVG(degree) from score b where a.cno=b.cno GROUP BY b.cno)
--34、查询所有任课教师的Tname和Depart.
SELECT t.tname,t.depart FROM teacher t WHERE EXISTS(SELECT 1 FROM course c WHERE c.tno=t.tno)
--方法2
SELECT t.tname,t.depart FROM teacher t WHERE t.tno IN(SELECT c.tno FROM course c);
--35、查询所有未讲课的教师的Tname和Depart.
SELECT t.tname,t.depart FROM teacher t WHERE NOT EXISTS(SELECT 1 FROM course c WHERE c.tno=t.tno )
--方法2
SELECT t.tname,t.depart FROM teacher t WHERE t.tno NOT IN(SELECT c.tno FROM course c);
--36、查询至少有2名男生的班号。
SELECT r.class from (SELECT T.CLASS,SUM(DECODE(t.ssex,'男',1,0)) m FROM STUDENT T GROUP BY T.CLASS) r WHERE r.m>=2
--方法2
SELECT S.CLASS FROM STUDENT S WHERE S.SSEX = '男' GROUP BY S.CLASS HAVING COUNT(1) > 1
--37、查询Student表中不姓“王”的同学记录。
SELECT s.* FROM student s WHERE s.sname NOT LIKE('王%')
--38、查询Student表中每个学生的姓名和年龄。
SELECT s.sname,to_char(SYSDATE,'yyyy')-to_char(s.sbirthday,'yyyy') 年龄 FROM student s
--39、查询Student表中最大和最小的Sbirthday日期值
SELECT MAX(s.sbirthday),MIN(s.sbirthday) FROM student s
--40、以班号和年龄从大到小的顺序查询Student表中的全部记录。
SELECT s.* FROM student s ORDER BY s.class,to_char(SYSDATE,'yyyymm')-to_char(s.sbirthday,'yyyymm') DESC
--41、查询“男”教师及其所上的课程。
SELECT c.cname FROM course c WHERE c.tno in（Select t.tno from teacher t where t.tsex='男'）
--方法2
SELECT t.tname, c.cname FROM course c,teacher t WHERE c.tno= t.tno AND t.tsex='男'
--42、查询(每个课程里)最高分同学的Sno、Cno和Degree列。
SELECT s.sno,s.cno,s.degree FROM score s WHERE s.degree IN (SELECT MAX(s.degree) FROM score s GROUP BY s.cno)
--方法2
SELECT s1.sno,s1.cno,s1.degree FROM score s1 WHERE s1.degree =
(SELECT MAX(s2.degree) FROM score s2 WHERE s2.cno=s1.cno GROUP BY s2.cno)
--43、查询和“李军”同性别的所有同学的Sname.
SELECT s.sname FROM student s WHERE s.ssex IN (SELECT s.ssex FROM student s WHERE s.sname='李军')
--44、查询和“李军”同性别并同班的同学Sname.
SELECT s.sname FROM student s WHERE s.ssex IN (SELECT s.ssex FROM student s WHERE s.sname='李军')
AND s.class IN (SELECT s.class FROM student s WHERE s.sname='李军')
--方法2
SELECT s.sname FROM student s WHERE (s.ssex,s.class) IN(SELECT s.ssex,s.class FROM student s WHERE s.sname='李军')
--45、查询所有选修“计算机导论”课程的“男”同学的成绩表
SELECT sc.* FROM score sc WHERE sc.sno IN(SELECT st.sno FROM student st WHERE st.ssex='男' )
AND sc.cno IN(SELECT c.cno FROM course c WHERE c.cname='计算机导论' )
--方法2
SELECT sc.* FROM student st,score sc,course c WHERE st.sno=sc.sno AND sc.cno=c.cno AND st.ssex='男' AND c.cname='计算机导论'