[记录]mysql添加列带注释

1.表结构语句

CREATE TABLE `directory` (                                                            
  `id` varchar(50) NOT NULL COMMENT '书页ID',                                       
  `novel_id` varchar(50) default NULL COMMENT '小说ID',                             
  `site_id` varchar(50) default NULL COMMENT '站点ID',                              
  `dir_url` varchar(256) default NULL COMMENT '书页链接',                 
    PRIMARY KEY  (`id`)                                                                 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=DYNAMIC

 

2.添加带注释列语句

alter table directory add index_url varchar(256) default null comment '章节书目链接' after dir_url;

 

3.删除列语句

alter table directory drop index_url;