数据库mysql实战

--创建图书管理系统的数据库
create database book;

--使用数据库
use book;

--创建读者信息表
create table reader(
    card_id char(18),
    name varchar(10),
    sex enum(‘男‘,‘女‘),
    age tinyint,
    tel char(11),
    balance decimal(7,3)
);

--查看数据库表列表
show tables from book;

--查看数据表的基本结构
show columns from reader;

desc reader;

--查看表的详细结构（可以用来显示数据表的创建语句）
show create table reader;

--修改表添加列
alter table reader add email varchar(30);

--查看表的基本结构
desc reader;

--修改表，在指定位置添加列
alter table reader add email2 varchar(30) after tel;

--修改列名
alter table reader change email2 email_bak varchar(30);

--修改列的数据类型
alter table reader modify email varchar(25);

--修改列的排列位置
alter table reader modify balance decimal(7,3) after email;

--删除列
alter table reader drop email_bak;

--修改表名
alter table reader rename to readerinfo;

--创建表时添加非空约束
create table bookinfo(
    book_id int,
    book_name varchar(20) not null
);

--删除非空约束
alter table bookinfo modify book_name varchar(20);

--通过修改表添加非空约束
alter table bookinfo modify book_name varchar(20) not null;

--创建表时添加主键约束
create table bookinfo(
    book_id int primary key,
    book_name varchar(20) not null
);

create table bookinfo(
    book_id int,
    book_name varchar(20) not null,
    constraint pk_id primary key(book_id)
);

--删除主键约束
ALTER TABLE bookinfo DROP PRIMARY KEY;


--通过修改表的方式添加主键约束
ALTER TABLE bookinfo ADD PRIMARY KEY(book_id);

--创建表时添加唯一约束
CREATE TABLE bookinfo(
    book_id INT PRIMARY KEY,
    book_name VARCHAR(20) NOT NULL UNIQUE 
);

--删除唯一约束
ALTER TABLE book_info DROP  KEY  uk_bname;


--通过修改表的方式添加唯一约束
ALTER TABLE bookinfo ADD UNIQUE(book_name);

--创建表时添加默认约束
CREATE TABLE bookinfo(
    book_id INT PRIMARY KEY,
    press VARCHAR(20)  DEFAULT ‘机械工业出版社‘
);


--删除默认约束
ALTER TABLE bookinfo ALTER COLUMN press DROP DEFAULT;


--通过修改表的方式添加默认约束
ALTER TABLE bookinfo ALTER COLUMN press SET DEFAULT ‘机械工业出版社’;

--创建表时添加外键约束

--图书类别表(父表)
CREATE TABLE bookcategory(
    category_id INT PRIMARY KEY,
    category VARCHAR(20),
    parent_id INT
);

--图书信息表(子表)
CREATE TABLE bookinfo(
    book_id INT PRIMARY KEY,
    book_category_id  INT,
    CONSTRAINT fk_cid FOREIGN KEY(book_category_id) REFERENCES bookcategory(category_id)
);


--删除外键约束
ALTER TABLE bookinfo DROP FOREIGN KEY fk_cid;


--通过修改表的方式添加外键约束
ALTER  TABLE  bookinfo  ADD  FOREIGN KEY(book_category_id) REFERENCES  bookcategory(category_id);

-- 打开图书管理的数据库
use book;

-- 查看库下都有哪些表
show tables;

-- 删除库中原有的表
drop table bookinfo;
drop table bookcategory, readerinfo;

-- 图书类别表
create table bookcategory(
category_id int primary key,
category varchar(20) not null unique,
parent_id int not null
);

-- 图书信息表
create table bookinfo(
book_id int primary key,
book_category_id int,
book_name varchar(20) not null unique,
author varchar(20) not null,
price float(5,2) not null,
press varchar(20) default ‘机械工业出版社‘,
pubdate date not null,
store int not null,
constraint fk_bcid foreign key(book_category_id) references bookcategory(category_id)
);


-- 读者信息表
create table readerinfo(
card_id char(18) primary key,
name varchar(20) not null,
sex enum(‘男‘,‘女‘,‘保密‘) default ‘保密‘,
age tinyint,
tel char(11) not null,
balance decimal(7,3) default 200
);

-- 借阅信息表
create table borrowinfo(
book_id int,
card_id char(18),
borrow_date date not null,
return_date date not null,
status char(11) not null,
primary key(book_id,card_id)
);

-- 为表的所有列插入数据
insert into bookcategory(category_id,category,parent_id)values(1,‘计算机‘,0);

insert into bookcategory values(2,‘医学‘,0);

-- 为表的指定列插入数据
insert into readerinfo(card_id,name,tel)values(‘210210199901011111‘,‘张飞‘,‘13566661111‘);


-- 同时插入多条记录
insert into bookcategory(category_id,category,parent_id)values(3,‘编程语言‘,1),(4,‘数据库‘,1),(5,‘儿科学‘,2);

-- 将查询结果插入的表中
insert into bookcategory select * from test where id>5;

-- 创建表时添加自增列
create table bookcategory_tmp(
    category_id int primary key auto_increment,
    category varchar(20) not null unique,
    parent_id int not null
)auto_increment=5;

-- 测试自增列
insert into bookcategory_tmp(category,parent_id)values(‘医学‘,0);

-- 创建表时添加自增列
create table bookcategory_tmp(
    category_id int primary key auto_increment,
    category varchar(20) not null unique,
    parent_id int not null
)auto_increment=5;

-- 测试自增列
insert into bookcategory_tmp(category,parent_id)values(‘医学‘,0);

-- 去掉自增列
alter table bookcategory_tmp modify category_id int;

-- 添加自增列
alter table bookcategory_tmp modify category_id int auto_increment;

-- 修改自增列的起始值
alter table bookcategory_tmp auto_increment = 15;

insert into bookcategory_tmp(category,parent_id)values(‘文学‘,0);


-- 删除图书信息表的外键
alter table bookinfo drop foreign key fk_bcid;

-- 为图书类别表添加自动编号的功能
alter table bookcategory modify category_id int auto_increment;

-- 恢复关联
alter table bookinfo add constraint fk_bcid foreign key(book_category_id)references bookcategory(category_id);

/*图书类别表*/
insert into bookcategory(category,parent_id)values(‘计算机‘,0),(‘医学‘,0),(‘编程语言‘,1),(‘数据库‘,1),(‘儿科学‘,2);

/*图书信息表*/
insert into bookinfo(book_id,book_category_id,book_name,author,price,press,pubdate,store)
values
(20150201,3, ‘Java编程思想‘, ‘(美)埃克尔‘, 79.8, default, ‘2007-04-01‘, 5),
(20150202,4, ‘PHP和MySQL Web开发‘, ‘Luke Welling等‘,95, default, ‘2009-04-01‘, 2),
(20150301,3, ‘Spring源码深度解析‘, ‘郝佳‘,69, ‘人民邮电出版社‘, ‘2013-09-01‘, 3),
(20160801,5, ‘中医儿科学‘, ‘汪受传‘, 136, ‘人民卫生出版社‘, ‘2011-04-01‘, 1),
(20170401,5, ‘小儿推拿秘笈‘, ‘李德修‘, 24.5, ‘人民卫生出版社‘, ‘2011-04-01‘,4);

/*读者信息表*/
insert into readerinfo(card_id,name,sex,age,tel,balance)
values
(210210199901011111,‘张飞‘,‘女‘,18,‘13566661111‘,300),
(210210199901012222,‘李月‘,‘女‘,19,‘13566662222‘,200),
(210210199901013333,‘王鹏‘,‘男‘,20,‘13566663333‘,300),
(210210199901014444,‘刘鑫‘,‘男‘,21,‘13566664444‘,400),
(210210199901015555,‘杨磊‘,‘男‘,22,‘13566665555‘,500);

/*
身份证号为210210199901011111的读者，2017-11-29借走了图书编号为20150201的这本书，
根据业务需求向借阅信息表插入一条借阅信息，更新读者信息表中的余额和图书信息表的库存，要求如下：
1、借书的期限为1个月。
2、借书的费用为：书的价格*5%
3、图书信息表中图书编号为20150201这本书的库存-1
*/

-- 向借阅信息表插入一条借阅信息
insert into borrowinfo(book_id,card_id,borrow_date,return_date,status)values(20150201,210210199901011111,‘2017-11-29‘,‘2017-12-29‘,‘否‘);

-- 更新读者信息表中的余额
-- 查看书的价格   79.80
select price from bookinfo where book_id = 20150201;

-- 更新余额
update readerinfo set balance = balance - 79.80*0.05 where card_id = ‘210210199901011111‘;
select * from readerinfo;

-- 更新图书信息表的库存
update bookinfo set store = store -1 where book_id = 20150201;
select * from bookinfo;

/*图书类别表*/
insert into bookcategory(category,parent_id)values(‘计算机‘,0),(‘医学‘,0),(‘编程语言‘,1),(‘数据库‘,1),(‘儿科学‘,2);
bookcategory
/*图书信息表*/
insert into bookinfo(book_id,book_category_id,book_name,author,price,press,pubdate,store)
values
(20150201,3, ‘Java编程思想‘, ‘(美)埃克尔‘, 79.8, default, ‘2007-04-01‘, 5),
(20150202,4, ‘PHP和MySQL Web开发‘, ‘Luke Welling等‘,95, default, ‘2009-04-01‘, 2),
(20150301,3, ‘Spring源码深度解析‘, ‘郝佳‘,69, ‘人民邮电出版社‘, ‘2013-09-01‘, 3),
(20160801,5, ‘中医儿科学‘, ‘汪受传‘, 136, ‘人民卫生出版社‘, ‘2011-04-01‘, 1),
(20170401,5, ‘小儿推拿秘笈‘, ‘李德修‘, 24.5, ‘人民卫生出版社‘, ‘2011-04-01‘,4);

/*读者信息表*/
insert into readerinfo(card_id,name,sex,age,tel,balance)
values
(210210199901011111,‘张飞‘,‘女‘,18,‘13566661111‘,300),
(210210199901012222,‘李月‘,‘女‘,19,‘13566662222‘,200),
(210210199901013333,‘王鹏‘,‘男‘,20,‘13566663333‘,300),
(210210199901014444,‘刘鑫‘,‘男‘,21,‘13566664444‘,400),
(210210199901015555,‘杨磊‘,‘男‘,22,‘13566665555‘,500);