一纵穿、工具準(zhǔn)備
安裝mysql數(shù)據(jù)庫(kù)管理系統(tǒng)；
安裝Navicat for MySQL工具（是一套為MySQL設(shè)計(jì)的強(qiáng)大數(shù)據(jù)庫(kù)管理及開發(fā)工具）。
二署隘、數(shù)據(jù)準(zhǔn)備
創(chuàng)建數(shù)據(jù)庫(kù)
CREATE DATABASE test;
建表
CREATE TABLE students
(sno VARCHAR(3) NOT NULL,
sname VARCHAR(4) NOT NULL,
ssex VARCHAR(2) NOT NULL,
sbirthday DATE,
class VARCHAR(5));
CREATE TABLE courses
(cno VARCHAR(5) NOT NULL,
cname VARCHAR(10) NOT NULL,
tno VARCHAR(10) NOT NULL);
CREATE TABLE scores
(sno VARCHAR(3) NOT NULL,
cno VARCHAR(5) NOT NULL,
degree NUMERIC(10, 1) NOT NULL) ;
CREATE TABLE teachers
(tno VARCHAR(3) NOT NULL,
tname VARCHAR(4) NOT NULL, tsex VARCHAR(2) NOT NULL,
tbirthday DATE NOT NULL, prof VARCHAR(6),
depart VARCHAR(10) NOT NULL);
插入數(shù)據(jù)
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,'曾華' ,'男' ,'1977-09-01',95033);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,'匡明' ,'男' ,'1975-10-02',95031);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,'王麗' ,'女' ,'1976-01-23',95033);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,'李軍' ,'男' ,'1976-02-20',95033);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,'王芳' ,'女' ,'1975-02-10',95031);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,'陸君' ,'男' ,'1974-06-03',95031);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('3-105' ,'計(jì)算機(jī)導(dǎo)論',825);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('3-245' ,'操作系統(tǒng)' ,804);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('6-166' ,'數(shù)據(jù)電路' ,856);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('9-888' ,'高等數(shù)學(xué)' ,100);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (103,'3-245',86);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (105,'3-245',75);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (109,'3-245',68);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (103,'3-105',92);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (105,'3-105',88);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (109,'3-105',76);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (101,'3-105',64);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (107,'3-105',91);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (108,'3-105',78);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (101,'6-166',85);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (107,'6-106',79);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (108,'6-166',81);
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (804,'李誠(chéng)','男','1958-12-02','副教授','計(jì)算機(jī)系');
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (856,'張旭','男','1969-03-12','講師','電子工程系');
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (825,'王萍','女','1972-05-05','助教','計(jì)算機(jī)系');
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (831,'劉冰','女','1977-08-14','助教','電子工程系');
創(chuàng)建好的數(shù)據(jù)如下：
數(shù)據(jù)庫(kù)結(jié)構(gòu).png
students表.png
courses表.png
scores表.png
teachers表.png
三、題目&答案&結(jié)果（如有不對(duì)的地方亚隙，還望不吝賜教）
- 查詢Student表中的所有記錄的Sname磁餐、Ssex和Class列。
SELECT sname,ssex,class
FROM students;
- 查詢教師所有的單位即不重復(fù)的Depart列阿弃。
SELECT DISTINCT depart
FROM teachers;
- 查詢Student表的所有記錄诊霹。
SELECT *
from students;
- 查詢Score表中成績(jī)?cè)?0到80之間的所有記錄。
SELECT *
from scores
WHERE degree BETWEEN 60 AND 80;
- 查詢Score表中成績(jī)?yōu)?5渣淳，86或88的記錄脾还。
SELECT *
FROM scores
WHERE degree IN (85,86,88);
- 查詢Student表中“95031”班或性別為“女”的同學(xué)記錄。
SELECT *
FROM students
WHERE class='95031' OR ssex='女';
- 以Class降序查詢Student表的所有記錄入愧。
SELECT *
FROM students
ORDER BY class DESC;
- 以Cno升序鄙漏、Degree降序查詢Score表的所有記錄。
SELECT *
FROM scores
ORDER BY cno ASC,degree DESC;
- 查詢“95031”班的學(xué)生人數(shù)棺蛛。
SELECT COUNT(1) AS stuNum
FROM students
WHERE class='95031';
- 查詢score表中的最高分的學(xué)生學(xué)號(hào)和課程號(hào)怔蚌。
SELECT sno,cno
FROM scores
ORDER BY degree DESC
LIMIT 1;
- 查詢‘3-105’號(hào)課程的平均分。
SELECT AVG(degree)
from scores
WHERE cno='3-105';
- 查詢score表中至少有5名學(xué)生選修的并以3開頭的課程的平均分?jǐn)?shù)旁赊。
SELECT cno,AVG(degree)
from scores
WHERE cno LIKE '3%'
GROUP BY cno
HAVING COUNT(sno)>=5;
# LIKE 操作符用于在 WHERE 子句中搜索列中的指定模式桦踊。
# "%" 可用于定義通配符（模式中缺少的字符）
- 查詢最低分大于70，最高分小于90的sno列终畅。
SELECT sno
FROM scores
GROUP BY sno
HAVING MIN(degree)>70 AND MAX(degree)<90;
- 查詢所有學(xué)生的sname籍胯、cno和degree列。
SELECT sname,cno,degree
FROM students INNER JOIN scores
ON students.sno=scores.sno;
GROUP BY sname;
- 查詢所有學(xué)生的sno离福、cname和degree列杖狼。
SELECT sno,cname,degree
FROM scores INNER JOIN courses
on scores.cno=courses.cno
ORDER BY sno;
image.png
- 查詢所有學(xué)生的sname、cname和degree列术徊。
SELECT sname,cname,degree
FROM students INNER JOIN scores
ON (students.sno=scores.sno)
INNER JOIN courses
on (scores.cno=courses.cno)
ORDER BY sname;
- 查詢“95033”班所選課程的平均分本刽。
SELECT cno,AVG(degree)
FROM students INNER JOIN scores
on (students.sno=scores.sno)
WHERE class='95033'
GROUP BY cno
ORDER BY cno;
image.png
- 假設(shè)使用如下命令建立了一個(gè)grade表：
create table grade(low number(3,0),upp number(3),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;
現(xiàn)查詢所有同學(xué)的sno、cno和rank列赠涮。
SELECT sno,cno,rank
FROM scores INNER JOIN grade
on (scores.degree>=grade.low AND degree<=grade.upp)
ORDER BY sno;
- 查詢選修“3-105”課程的成績(jī)高于“109”號(hào)同學(xué)成績(jī)的所有同學(xué)的記錄子寓。
#答案一
SELECT *
FROM scores
WHERE cno='3-105' AND degree>(SELECT degree FROM scores WHERE cno='3-105' AND sno='109')
ORDER BY sno;
#答案二
SELECT s1.sno,s1.degree
FROM scores AS s1 INNER JOIN scores AS s2
ON(s1.cno=s2.cno AND s1.degree>s2.degree)
WHERE s1.cno='3-105' AND s2.sno='109'
ORDER BY s1.sno;
- 查詢score中選學(xué)一門以上課程的同學(xué)中分?jǐn)?shù)為非最高分成績(jī)的記錄。
SELECT *
FROM scores a
WHERE sno IN (SELECT sno FROM scores GROUP BY sno HAVING count(cno)>1)
AND degree<( SELECT max(degree) FROM scores b WHERE b.cno = a.cno);
- 查詢成績(jī)高于學(xué)號(hào)為“109”笋除、課程號(hào)為“3-105”的成績(jī)的所有記錄斜友。
同19
- 查詢和學(xué)號(hào)為108的同學(xué)同年出生的所有學(xué)生的sno、sname和sbirthday列垃它。
SELECT sno,sname,sbirthday
FROM students
WHERE YEAR(sbirthday)=(SELECT YEAR(sbirthday) FROM students WHERE sno='108')
ORDER BY sno;
- 查詢“張旭“教師任課的學(xué)生成績(jī)鲜屏。
SELECT sno,degree
FROM scores
WHERE cno=(SELECT cno FROM courses WHERE tno=(SELECT tno FROM teachers WHERE tname='張旭'))
ORDER BY sno;
- 查詢選修某課程的同學(xué)人數(shù)多于5人的教師姓名烹看。
SELECT tname
FROM teachers
WHERE tno=(SELECT tno FROM courses WHERE cno=(SELECT cno FROM scores GROUP BY(cno) HAVING COUNT(sno)>5));
- 查詢95033班和95031班全體學(xué)生的記錄。
SELECT students.*,scores.cno,scores.degree
FROM students,scores
WHERE class IN (95033,95031) AND students.sno=scores.sno
ORDER BY students.sno;
- 查詢存在有85分以上成績(jī)的課程cno.
SELECT DISTINCT cno
FROM scores
WHERE degree>85;
- 查詢出“計(jì)算機(jī)系“教師所教課程的成績(jī)表洛史。
SELECT *
FROM scores
WHERE cno IN(SELECT cno FROM courses WHERE tno IN(SELECT tno FROM teachers WHERE depart='計(jì)算機(jī)系'));
- 查詢“計(jì)算機(jī)系”與“電子工程系“不同職稱的教師的tname和prof惯殊。
SELECT tname,prof
FROM teachers
WHERE depart='計(jì)算機(jī)系' AND prof NOT IN (SELECT prof FROM teachers WHERE depart='電子工程系');
image.png
- 查詢選修編號(hào)為“3-105“課程且成績(jī)至少高于選修編號(hào)為“3-245”的同學(xué)的cno、sno和degree,并按Degree從高到低次序排序也殖。
SELECT cno,sno,degree
FROM scores a
WHERE cno='3-105' AND degree>ANY(SELECT degree FROM scores b WHERE cno='3-245' AND b.sno=a.sno)
ORDER BY degree DESC;
# ANY 代表括號(hào)內(nèi)的任意一個(gè)
- 查詢選修編號(hào)為“3-105”且成績(jī)高于選修編號(hào)為“3-245”課程的同學(xué)的cno土思、sno和degree.
SELECT sno,cno,degree
FROM scores a
WHERE cno='3-105' AND degree>ALL(SELECT degree FROM scores b WHERE cno='3-245' AND b.sno=a.sno);
# ALL代表所有的
- 查詢所有教師和同學(xué)的name、sex和birthday.
SELECT sname AS name,ssex AS sex,sbirthday AS birthday
FROM students
UNION
SELECT tname AS name,tsex AS sex,tbirthday AS birthday
FROM teachers;
# UNION 操作符用于合并兩個(gè)或多個(gè) SELECT 語(yǔ)句的結(jié)果集忆嗜。請(qǐng)注意己儒，UNION 內(nèi)部的 SELECT 語(yǔ)句必須擁有相同數(shù)量的列。列也必須擁有相似的數(shù)據(jù)類型捆毫。同時(shí)闪湾，每條 SELECT 語(yǔ)句中的列的順序必須相同。
- 查詢所有“女”教師和“女”同學(xué)的name绩卤、sex和birthday.
SELECT tname AS name, tsex AS sex, tbirthday AS birthday
FROM teachers
WHERE tsex='女'
UNION
SELECT sname AS name, ssex AS sex, sbirthday AS birthday
FROM students
WHERE ssex='女'
- 查詢成績(jī)比該課程平均成績(jī)低的同學(xué)的成績(jī)表途样。
SELECT *
FROM scores a
WHERE degree<(SELECT AVG(degree) FROM scores b WHERE b.cno=a.cno);
- 查詢所有任課教師的tname和depart.
SELECT tname,depart
FROM teachers
WHERE tno IN(SELECT tno from courses);
- 查詢所有未講課的教師的tname和depart.
SELECT tname,depart
FROM teachers
WHERE tno NOT IN(SELECT tno from courses);
- 查詢至少有2名男生的班號(hào)。
SELECT class
FROM students
WHERE ssex='男'
GROUP BY class
HAVING COUNT(sno)>=2;
- 查詢Student表中不姓“王”的同學(xué)記錄省艳。
SELECT *
FROM students
WHERE sname NOT LIKE '王%';
- 查詢Student表中每個(gè)學(xué)生的姓名和年齡娘纷。
SELECT sname,YEAR(NOW())-YEAR(sbirthday) AS sage
FROM students;
# YEAR(NOW())當(dāng)前年，YEAR(sbirthday)生日取年
- 查詢Student表中最大和最小的sbirthday日期值跋炕。
SELECT MAX(sbirthday),MIN(sbirthday)
FROM students;
- 以班號(hào)和年齡從大到小的順序查詢Student表中的全部記錄赖晶。
SELECT *
FROM students
ORDER BY class DESC,sbirthday ASC;
- 查詢“男”教師及其所上的課程。
SELECT tname,tsex,cname
FROM teachers INNER JOIN courses
WHERE tsex='男' and courses.tno=teachers.tno;
- 查詢最高分同學(xué)的sno辐烂、cno和degree列遏插。
SELECT sno,cno,degree
FROM scores
WHERE degree=(SELECT MAX(degree) FROM scores);
- 查詢和“李軍”同性別的所有同學(xué)的sname.
SELECT sname
FROM students
WHERE ssex=(SELECT ssex FROM students WHERE sname='李軍');
image.png
- 查詢和“李軍”同性別并同班的同學(xué)sname.
SELECT sname
FROM students a
WHERE ssex=(SELECT ssex FROM students b WHERE sname='李軍' AND a.class=b.class);
- 查詢所有選修“計(jì)算機(jī)導(dǎo)論”課程的“男”同學(xué)的成績(jī)表
SELECT *
FROM scores
WHERE cno=(SELECT cno FROM courses WHERE cname='計(jì)算機(jī)導(dǎo)論')AND sno=ANY(SELECT sno FROM students WHERE ssex='男');
