mysql修改已存在的表增加ID属性为auto_increment自动增长的方法_MySQL
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2024-02-07 17:03:58
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bitsCN.com
mysql修改已存在的表增加ID属性为auto_increment自动增长 今天有需要将已经存在表设置自动增长属性具体如下alter table customers change id id int not null auto_increment primary key; 扩展知识：//添加字段并设置主键ALTER TABLE tabelname ADD new_field_id int(5) unsigned default 0 not null auto_increment ,ADD primary key (new_field_id);//加主关键字的索引ALTER TABLE tablename ADD primary key(id);//加索引 ALTER TABLE tablename CHANGE depno depno int(5) not null;ALTER TABLE tablename ADD INDEX 索引名 (字段名1[，字段名2 …]);ALTER TABLE tablename ADD INDEX emp_name (name);//加唯一限制条件的索引ALTER TABLE tablename ADD UNIQUE emp_name2(cardnumber);//删除某个索引ALTER TABLE tablename DROP INDEX emp_name; //增加字段：ALTER TABLE table_name ADD field_name field_type;//删除字段ALTER TABLE table_name DROP field_name;//重命名列ALTER TABLE table_name CHANGE field_name1 field_name2 integer;//调整字段顺序 ALTER TABLE `users` CHANGE `user_password` `user_password` varchar( 20 ) NOT NULL AFTER user_name;//改变列的类型ALTER TABLE table_name CHANGE field_name field_name bigint not null;ALTER TABLE infos CHANGE list list tinyint not null default '0';//修改原字段名称及类型： ALTER TABLE table_name CHANGE old_field_name new_field_name field_type;//重命名表ALTER TABLE table_name rename new_table_name;//级联更新 和 删除(红色部分,不区分大小写 )DROP TABLE IF EXISTS `mail_model`;create TABLE mail_model(id varchar(50) primary key not null ,mail_filename varchar(200),content varchar(2000))ENGINE=InnoDB DEFAULT CHARSET=gbk;DROP TABLE IF EXISTS `mail_model_extend`;create TABLE mail_model_extend(id int(6) auto_increment not null primary key,rid varchar(50) not null,content varchar(2000),INDEX (RID),FOREIGN KEY (RID) REFERENCES mail_model(ID) ON DELETE CASCADE ON UPDATE CASCADE)ENGINE=InnoDB DEFAULT CHARSET=gbk; 作者 DouglasLau bitsCN.com
mysql修改已存在的表增加ID属性为auto_increment自动增长 今天有需要将已经存在表设置自动增长属性具体如下alter table customers change id id int not null auto_increment primary key; 扩展知识：//添加字段并设置主键ALTER TABLE tabelname ADD new_field_id int(5) unsigned default 0 not null auto_increment ,ADD primary key (new_field_id);//加主关键字的索引ALTER TABLE tablename ADD primary key(id);//加索引 ALTER TABLE tablename CHANGE depno depno int(5) not null;ALTER TABLE tablename ADD INDEX 索引名 (字段名1[，字段名2 …]);ALTER TABLE tablename ADD INDEX emp_name (name);//加唯一限制条件的索引ALTER TABLE tablename ADD UNIQUE emp_name2(cardnumber);//删除某个索引ALTER TABLE tablename DROP INDEX emp_name; //增加字段：ALTER TABLE table_name ADD field_name field_type;//删除字段ALTER TABLE table_name DROP field_name;//重命名列ALTER TABLE table_name CHANGE field_name1 field_name2 integer;//调整字段顺序 ALTER TABLE `users` CHANGE `user_password` `user_password` varchar( 20 ) NOT NULL AFTER user_name;//改变列的类型ALTER TABLE table_name CHANGE field_name field_name bigint not null;ALTER TABLE infos CHANGE list list tinyint not null default '0';//修改原字段名称及类型： ALTER TABLE table_name CHANGE old_field_name new_field_name field_type;//重命名表ALTER TABLE table_name rename new_table_name;//级联更新 和 删除(红色部分,不区分大小写 )DROP TABLE IF EXISTS `mail_model`;create TABLE mail_model(id varchar(50) primary key not null ,mail_filename varchar(200),content varchar(2000))ENGINE=InnoDB DEFAULT CHARSET=gbk;DROP TABLE IF EXISTS `mail_model_extend`;create TABLE mail_model_extend(id int(6) auto_increment not null primary key,rid varchar(50) not null,content varchar(2000),INDEX (RID),FOREIGN KEY (RID) REFERENCES mail_model(ID) ON DELETE CASCADE ON UPDATE CASCADE)ENGINE=InnoDB DEFAULT CHARSET=gbk; 作者 DouglasLau bitsCN.com