概述
續一下之前講的MySQL資料庫sql基礎練習第三部分，大家可以跟着做一下。
建表語句
CREATE TABLE students
(sno VARCHAR(3) NOT NULL,
sname VARCHAR(4) NOT NULL,
ssex VARCHAR(2) NOT NULL,
sbirthday DATETIME,
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 DATETIME NOT NULL, prof VARCHAR(6),
depart VARCHAR(10) NOT NULL) 插入資料
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' ,'計算機導論',825);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('3-245' ,'作業系統' ,804);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('6-166' ,'資料電路' ,856);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES ('9-888' ,'高等數學' ,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','男','1958-12-02','副教授','計算機系');
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','計算機系');
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (831,'劉冰','女','1977-08-14','助教','電子工程系'); 題目
1、查詢所有教師和同學的name、sex和birthday.
2、查詢所有“女”教師和“女”同學的name、sex和birthday.
3、查詢成績比該課程平均成績低的同學的成績表。
4、查詢所有任課教師的Tname和Depart.
5 查詢所有未講課的教師的Tname和Depart.
6、查詢至少有2名男生的班号。
7、查詢Student表中不姓“王”的同學記錄。
8、查詢Student表中每個學生的姓名和年齡。
9、查詢Student表中最大和最小的Sbirthday日期值。
10、以班号和年齡從大到小的順序查詢Student表中的全部記錄。
11、查詢“男”教師及其所上的課程。
12、查詢最高分同學的Sno、Cno和Degree列。
13、查詢和“李軍”同性别的所有同學的Sname.
14、查詢和“李軍”同性别并同班的同學Sname.
15、查詢所有選修“計算機導論”課程的“男”同學的成績表
答案
1.查詢所有教師和同學的name、sex和birthday.
SELECT Sname,Ssex,Sbirthday FROM Students UNION SELECT Tname,Tsex,Tbirthday FROM Teachers; 2.查詢所有“女”教師和“女”同學的name、sex和birthday.
SELECT Sname,Ssex,Sbirthday FROM Students WHERE Ssex='女' UNION SELECT Tname,Tsex,Tbirthday FROM Teachers WHERE Tsex='女'; 3.查詢成績比該課程平均成績低的同學的成績表。
SELECT s1.* FROM Scores AS s1 INNER JOIN ( SELECT Cno,AVG(Degree) AS aDegree FROM Scores GROUP BY Cno) s2 ON(s1.Cno=s2.Cno AND s1.Degree<s2.aDegree); 4.查詢所有任課教師的Tname和Depart.
SELECT Tname,Depart FROM Teachers WHERE Tno IN( SELECT Tno FROM Courses); 5.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); 6.查詢至少有2名男生的班号。
SELECT Class,COUNT(1) AS boyCount FROM Students WHERE Ssex='男' GROUP BY Class HAVING boyCount>=2; 7.查詢Student表中不姓“王”的同學記錄。
SELECT * FROM Students WHERE Sname NOT LIKE '王%'; 8.查詢Student表中每個學生的姓名和年齡。
SELECT Sname,YEAR(NOW())-YEAR(Sbirthday) AS Sage FROM Students; 9.查詢Student表中最大和最小的Sbirthday日期值。
SELECT MIN(Sbirthday),MAX(Sbirthday) FROM Students; 10.以班号和年齡從大到小的順序查詢Student表中的全部記錄。
SELECT * FROM Students ORDER BY Class DESC,Sbirthday ASC; 11.查詢“男”教師及其所上的課程。
SELECT Teachers.Tname,Courses.Cname FROM Teachers INNER JOIN Courses ON(Teachers.Tno=Courses.Tno) WHERE Teachers.Tsex='男'; 12.查詢最高分同學的Sno、Cno和Degree列。
SELECT * FROM Scores GROUP BY Cno HAVING Degree=Max(Degree); 13.查詢和“李軍”同性别的所有同學的Sname.
SELECT s1.Sname FROM Students AS s1 INNER JOIN Students AS s2 ON(s1.Ssex=s2.Ssex) WHERE s2.Sname='李軍'; 14.查詢和“李軍”同性别并同班的同學Sname.
SELECT s1.Sname FROM Students AS s1 INNER JOIN Students AS s2 ON(s1.Ssex=s2.Ssex AND s1.Class=s2.Class) WHERE s2.Sname='李軍'; SELECT * FROM Scores WHERE Sno IN ( SELECT Sno FROM Students
WHERE Ssex='男') AND Cno IN ( SELECT Cno FROM Courses WHERE Cname='計算機導論'); ![《高性能MySQL》讀書筆記（上）[圖]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)