ALTER TABLE tbl_name MODIFY col_name column_definition 其中column_definition字段需要包括以下内容: 1、该列的数据类型及AUTO_INCREMENT字段; 2、如该列必须为NOT NULL及PRIMARY KEY(UNIQUE)属性。如果不是,需添加相应定义。 举个例子。已存在表test,结构如下: mysql> desc test; +----------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------+------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | | | username | varchar(15) | NO | | NULL | | +----------+------------------+------+-----+---------+----------------+ 先需要给主键列id添加AUTO_INCREMENT属性,只需执行以下指令即可:alter table test MODIFY id INT UNSIGNED AUTO_INCREMENT; 执行成功后,再查看表test的结构,即可看到auto_increment属性: mysql> desc test; +----------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------+------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | username | varchar(15) | NO | | NULL | | +----------+------------------+------+-----+---------+----------------+ 转载请保留固定链接: https://linuxeye.com/database/992.html |