mysql：查詢當前數據的所在行號

select  @rownum:=@rownum+1 rownum, sys_organ.* from (select @rownum:=0) r, sys_organ order by sys_id desc;

 

更新某一字段等於所在行號：

set @num = 0;

update sys_organ set organ_num = (@num := @num + 1);