建表：
CREATE TABLE `my_tb` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`parent_code` varchar(255) DEFAULT NULL,
`code` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;
初始数据：
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES ('', '');
查询行号：
-- 生成 行号
select @r:=@r+1 as row_num , a.* from my_tb a ,(select @r:=0) b
显示分组号：
-- 生成 分组排序号 select
@group_row:=CASE when @parent_code=a.parent_code then @group_row+1 else 1 end as groupRow,
@parent_code:=a.parent_code as parent_code,
a.code from my_tb a ,( select @group_row:=1, @parent_code:='') as b
ORDER BY a.parent_code , a.code