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 (‘01‘, ‘001‘); INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES (‘01‘, ‘002‘); INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES (‘02‘, ‘001‘); INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES (‘01‘, ‘003‘); INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES (‘02‘, ‘002‘); INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES (‘03‘, ‘001‘); INSERT INTO `my_tb` ( `parent_code`, `code`) VALUES (‘04‘, ‘001‘);
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
时间: 2024-10-13 10:50:54