MySQL基础之库和表的管理

create database  [if not exists]库名;

CREATE DATABASE IF NOT EXISTS books ;

RENAME DATABASE books TO 新库名;

ALTER DATABASE books CHARACTER SET gbk;

DROP DATABASE IF EXISTS books;

create table 表名(
	列名 列的类型【(长度) 约束】,
	列名 列的类型【(长度) 约束】,
	列名 列的类型【(长度) 约束】,
	...
	列名 列的类型【(长度) 约束】


)

CREATE TABLE book(
	id INT,#编号
	bName VARCHAR(20),#图书名
	price DOUBLE,#价格
	authorId  INT,#作者编号
	publishDate DATETIME#出版日期

);


DESC book;

CREATE TABLE IF NOT EXISTS author(
	id INT,
	au_name VARCHAR(20),
	nation VARCHAR(10)

)
DESC author;

alter table 表名 add|drop|modify|change column 列名 【列类型 约束】;

ALTER TABLE book CHANGE COLUMN publishdate pubDate DATETIME;

ALTER TABLE book MODIFY COLUMN pubdate TIMESTAMP;

ALTER TABLE author ADD COLUMN annual DOUBLE; 

ALTER TABLE book_author DROP COLUMN  annual;

ALTER TABLE author RENAME TO book_author;

DESC book;

DROP TABLE IF EXISTS book_author;

SHOW TABLES;

DROP DATABASE IF EXISTS 旧库名;
CREATE DATABASE 新库名;


DROP TABLE IF EXISTS 旧表名;
CREATE TABLE  表名();

INSERT INTO author VALUES
(1,'村上春树','日本'),
(2,'莫言','中国'),
(3,'冯唐','中国'),
(4,'金庸','中国');

SELECT * FROM Author;
SELECT * FROM copy2;

CREATE TABLE copy LIKE author;

CREATE TABLE copy2 
SELECT * FROM author;

CREATE TABLE copy3
SELECT id,au_name
FROM author 
WHERE nation='中国';

CREATE TABLE copy4 
SELECT id,au_name
FROM author
WHERE 0;