在mysql结果集中，增加序号列

原SQL

select terminal_no from biz_terminal_info where length(terminal_no)>7 group by terminal_no;

修改后

SET @mycnt=0;
select @mycnt := @mycnt +1 as mycnt,terminal_no from biz_terminal_info where length(terminal_no)>7 group by terminal_no;

效果