mysql 常用的 ddl 语句。

# add table
CREATE TABLE tb_user(

id INT(4) NOT NULL auto_increment COMMENT '自增长ID',
name varchar(200) NOT NULL DEFAULT '' COMMENT '姓名',
gender int(4) NOT NULL DEFAULT 0 COMMENT '性别',
birthday datetime NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT '生日',
PRIMARY KEY (id),
KEY Ix_name (name) USING BTREE
)ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='个人信息表';

#alter 增/改/删，字段
ALTER TABLE tb_user ADD weight varchar(200) AFTER gender;
ALTER TABLE tb_user	modify birthtime int DEFAULT 0 COMMENT '生日时间戳';
ALTER TABLE tb_user change birthtime birthday datetime NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT '生日' AFTER `weight`;;
ALTER TABLE tb_user	drop COLUMN weight;

#加/删，索引
CREATE INDEX Ix_ge ON tb_user (gender);
DROP INDEX Ix_ge ON tb_user;

ALTER TABLE tb_user ADD INDEX Ix_ge(gender);
ALTER TABLE tb_user DROP INDEX Ix_ge;

#唯一索引
CREATE UNIQUE INDEX index_name ON tb_user (birthday);