sql1

-- 4.使用sql语句查询出表中的所有内容

SELECT * FROM student

-- 5.使用sql语句查询出表中所有同学的id,name,score

SELECT id,sname,score FROM student

-- 6.更改useremail字段的数据类型为varchar(50)

alter table student modify column useremail VARCHAR(50)

-- 7.向表中添加一个字段,字段名称为“pingjia”,字段类型为varchar(20)

ALTER TABLE student ADD pingjia VARCHAR(20)

-- 8.更改姓名是张三的同学的分数为88

UPDATE student SET score=88 WHERE sname="张三"

-- 9.如果80分为及格线,查询出所有及格的同学的详细信息

SELECT * from student WHERE score>80

-- 10.把姓名是“小红”的同学的分数在原来的基础上+40

UPDATE student SET score=score+40 WHERE sname="小红"

-- 11.使用关键字in,查询id值是1或5或7的同学的基本信息

SELECT * FROM student WHERE id in(1,5,7)

-- 12.查询id值在5至8的所有同学的基本信息

SELECT * FROM student where id>=5 AND id<=8

-- 13.查询姓名是小红并且分数大于60的同学的基本信息

SELECT * FROM student WHERE sname="小红" AND score>60

-- 14.查询姓名是小红或者分数大于90的同学的基本信息

SELECT * FROM student WHERE sname="小红" OR score>90

-- 15.查询score字段值是NULL的同学的基本信息

SELECT * FROM student WHERE score is NULL

-- 16.查询score字段值不是NULL的同学的id和name

SELECT id,sname FROM student WHERE score is NOT NULL

----------------------------------------------------------------------------------------------------------------

-- 创建课程(lesson)

-- id(整形主键)name(课程名称)

CREATE TABLE lesson(

id INT PRIMARY KEY auto_increment,

`name` VARCHAR(20)

)

-- 创建一个班级(cls),包含字段

-- id(整形主键)

-- name(班级名称)

-- number(班级人数)

-- lesson_id(课程名称id)

CREATE TABLE cls(

id INT PRIMARY KEY auto_increment,

`name` varchar(20),

number int,

lesson_id int

)

-- 在lesson表中插入两数据

INSERT into lesson(name) VALUES('python高级'),('数据库vue')

-- 在班级表中插入6条记录,

INSERT into cls(name, number, lesson_id) VALUES

('1905A',22,1),

('1906A',44,1),

('1904A',33,1),

('1901A',18,2),

('1902A',48,2),

('1903A',56,2)

-- 查询类型为 'python高级' 的所有班级、人员数量less

SELECT c.name,c.number FROM cls c,lesson l WHERE c.lesson_id=l.id AND l.name="python高级"

-- 查询每个班级中 人数最多、最少

SELECT max(number),min(number) FROM cls c,lesson l WHERE c.lesson_id=l.id

-- 查询所有人员数量大于平均人数的班级,并且按班级人数降序排序

SELECT c.name FROM cls c WHERE number>(SELECT avg(number) FROM cls)ORDER BY number desc

-- 修改cls表中'1902A'班级数量为44

UPDATE cls SET number=44 WHERE name="1902A"

------------------------------------------------------------------------------------------------------------------------------------

-- 2. 在test数据库中创建yuangong表,表中添加如下记录,表

CREATE TABLE yuangong(

sid INT PRIMARY KEY auto_increment,

sname varchar(20) not NULL,

sex VARCHAR(20) DEFAULT '男',

job VARCHAR(20) not NULL,

birthday date,

salary int,

comm int,

withhold int)

INSERT INTO yuangong(sid,sname,sex,job,birthday,salary,comm,withhold)

VALUES(1001,"张三","男","高级工程师","1975-1-1",2200,1100,200),

      (1002,"李四","女","助工","1985-1-1",1200,200,100),

      (1003,"王五","男","工程师","1978-11-11",1900,700,200),

      (1004,"赵六","男","工程师","1979-1-1",1950,700,150)

-- 2. 修改表名为”emp”

ALTER TABLE yuangong rename emp

-- 3. 向表中添加字段Hobby,设置类型为varchar(50),设置唯一约束

ALTER TABLE emp ADD hobby VARCHAR(50) not null

-- 4. 使用desc语句查看表结构

DESC emp

-- 5. 向表中添加记录,字段对应值分别为(1005,林青霞,女,架构师,1969-12-12,8000,NULL,100,阅读)

INSERT INTO emp VALUES(1005,"林青霞","女","架构师","1969-12-12",8000,NULL,100,"阅读")

-- 6. 修改sname字段的类型为varchar(20)

ALTER TABLE emp MODIFY COLUMN sname varchar(20)

-- 7. 查询表中sid字段的值从是1002或1003或1005员工的所有记录(使用关键字in)

SELECT * FROM emp WHERE sid=1002 OR sid=1003 or sid=1005

-- 8. 修改表中job值是高级工程师员工的job为“架构师”

UPDATE emp SET job="架构师" WHERE job="高级工程师"

-- 9. 删除表中sid是1003并且job是王五的员工的记录

DELETE FROM emp WHERE sid=1003 AND job="王五"

-- 10. 修改表中姓名是1004员工的salary在原来的基础上-300(

UPDATE emp SET salary=salary-300 WHERE sid="1004"

---------------------------------------------------------------------------------------------------------------------------

-- 自定义类Book,表名为book,表包含以下字段:

--  id    (主键,自增长)

-- bookname (书名,不能为空)

-- price  (价格,不能为空)

-- author  (作者)

-- publish    (出版社)

CREATE TABLE book(

id int PRIMARY KEY auto_increment,

bookname VARCHAR(20) not NULL,

price INT NOT null,

author varchar(20),

publish VARCHAR(20)

)

INSERT INTO book(bookname,price,author,publish)

VALUES("北平无故事","25","刘和平","作家出版社"),

("人间失格","16","太宰治著","作家出版社 "),

("高兴","14","贾平凹","人民出版社"),

("源氏物语","57","刘和平","人民出版社"),

("卡夫卡文集","9","卡夫卡","邮电出版社"),

("大家 ","12","王蒙","邮电出版社"),

("拉片子","37","杨健","清华出版社"),

("古代散文","5","归有光","安徽出版社"),

("百花散文","6","孙虹选","百花文艺出版社"),

("方令孺散文集","5","方令孺","安徽文艺")

-- 3) (10分)查询所有图书的信息,并按价格降序显示。

SELECT * FROM book ORDER BY price DESC

-- 4) (10分)查询所有作家出版社的图书信息,并按价格降序显示

SELECT *FROM book WHERE publish="作家出版社" ORDER BY price DESC

-- 5) (10分)查询出所有刘和平的图书信息 ,并输出

SELECT *FROM book WHERE author="刘和平"

-- 6) (10分)删除ID是2的记录,如果没有相关记录则提示

DELETE FROM book WHERE id=2

-- 7) (10分)将所有价格不足10元的图书调到10元,并查看信息

UPDATE book SET price=price+10 WHERE price<10

-- 8) (10分)查看所有图书的价格情况,并升序显示

SELECT bookname,price FROM book ORDER BY price asc

-- 9) (10分)查看所有价格低于20元的图收信息

SELECT * FROM book WHERE price<20

-- 10) (10分)所有图书的价格上调20%,并查看信息

UPDATE book SET price=price*1.2

SELECT * FROM book

你可能感兴趣的:(sql1)