mysql表结构操作

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CREATE DATABASE sqltest;

#DROP DATABASE sqltest;
USE sqltest;

CREATE TABLE USER (
	id INT (10) UNSIGNED NOT NULL COMMENT 'Id',
	username VARCHAR (64) NOT NULL DEFAULT 'default' COMMENT '用户名',
	PASSWORD VARCHAR (64) NOT NULL DEFAULT 'default' COMMENT '密码',
	email VARCHAR (64) NOT NULL DEFAULT 'default' COMMENT '邮箱'
) COMMENT = '用户表';

#复制表
CREATE TABLE vip_user AS
SELECT * FROM user;

DROP TABLE USER;

#添加列
ALTER TABLE user
ADD age int(3);
#删除列
ALTER TABLE user
DROP COLUMN age;
#修改列
ALTER TABLE `user`
MODIFY COLUMN age tinyint;
#添加主键
ALTER TABLE user
ADD PRIMARY KEY (id);
#删除主键
ALTER TABLE user
DROP PRIMARY KEY;