MySQL测试题

创建 student 表

CREATE  TABLE  student (id  INT(10) AUTO_INCREMENT PRIMARY KEY  ,name  VARCHAR(20)  NOT NULL ,sex  VARCHAR(4)  ,birth  YEAR,department  VARCHAR(20) ,address  VARCHAR(50) );

创建 score 表

CREATE  TABLE  score (id  INT(10) PRIMARY KEY  AUTO_INCREMENT ,stu_id  INT(10)  NOT NULL ,c_name  VARCHAR(20) ,grade  INT(10));

为 student 表插入记录：

INSERT INTO student VALUES( 901,'张老大', '男',1985,'计算机系', '北京市海淀区');INSERT INTO student VALUES( 902,'张老二', '男',1986,'中文系', '北京市昌平区');INSERT INTO student VALUES( 903,'张三', '女',1990,'中文系', '湖南省永州市');INSERT INTO student VALUES( 904,'李四', '男',1990,'英语系', '辽宁省阜新市');INSERT INTO student VALUES( 905,'王五', '女',1991,'英语系', '福建省厦门市');INSERT INTO student VALUES( 906,'王六', '男',1988,'计算机系', '湖南省衡阳市');

向 score 表插入记录：

INSERT INTO score VALUES(NULL,901, '计算机',98);INSERT INTO score VALUES(NULL,901, '英语', 80);INSERT INTO score VALUES(NULL,902, '计算机',65);INSERT INTO score VALUES(NULL,902, '中文',88);INSERT INTO score VALUES(NULL,903, '中文',95);INSERT INTO score VALUES(NULL,904, '计算机',70);INSERT INTO score VALUES(NULL,904, '英语',92);INSERT INTO score VALUES(NULL,905, '英语',94);INSERT INTO score VALUES(NULL,906, '计算机',90);INSERT INTO score VALUES(NULL,906, '英语',85);

查询 student 表的所有记录

SELECT * FROM student;

查询 student 标的第2条到4条记录

SELECT * FROM student LIMIT 1,3;

从student表查询所有学生的学号（id）、姓名（name）和院系（department）的信息

SELECT id,name,department FROM student;

从 student 表中查询计算机系和英语系的学生的信息

SELECT * FROM student WHERE department IN('计算机系','英语系');

从 student 表中查询年龄18~22岁的学生信息

SELECT * FROM student WHERE (2017-birth) BETWEEN 22 AND 26;

从 student 表中查询每个院系有多少人

SELECT department,COUNT(*) FROM student GROUP BY department;

从 score 表中查询每个科目的最高分

SELECT MAX(grade),c_name FROM score GROUP BY c_name;

查询李四的考试科目（c_name）和考试成绩（grade）

SELECT sc.c_name,sc.grade FROM score AS scLEFT JOIN student AS stON sc.stu_id=st.idWHERE st.name='李四';

用连接的方式查询所有学生的信息和考试信息

SELECT * FROM studentLEFT JOIN scoreON score.stu_id=student.id;

计算每个学生的总成绩

SELECT st.id,st.name,SUM(grade) FROM student AS stLEFT JOIN score AS scON sc.stu_id=st.idGROUP BY st.id;

计算每个考试科目的平均成绩

SELECT c_name,AVG(grade) FROM score GROUP BY c_name;

查询计算机成绩低于95的学生信息

SELECT * FROM studentWHERE id IN(SELECT stu_id FROM scoreWHERE c_name="计算机" and grade<95);

查询同时参加计算机和英语考试的学生的信息

SELECT *  FROM studentWHERE id = ANY( SELECT stu_id FROM score WHERE stu_id IN (SELECT stu_id FROMscore WHERE c_name=  '计算机')AND c_name= '英语' );

将计算机考试成绩按从高到低进行排序

SELECT c_name,grade FROM score WHERE c_name='计算机' ORDER BY grade DESC;

从 student 表和 score 表中查询出学生的学号，然后合并查询结果

SELECT id FROM studentUNIONSELECT stu_id FROM score;

查询姓张或者姓王的同学的姓名、院系和考试科目及成绩

SELECT st.name,st.department,sc.c_name,sc.grade FROM student AS st LEFT JOIN score AS sc ON sc.stu_id=st.idWHERE st.name LIKE '张%' OR st.name LIKE'王%';

查询都是湖南的学生的姓名、年龄、院系和考试科目及成绩

SELECT st.name,(2017-birth)AS '年龄',st.department,sc.c_name,sc.gradeFROM student AS st LEFT JOIN score AS sc ON sc.stu_id=st.idWHERE st.address LIKE '湖南%';