17、雨 "哗哗…… "地下起来,就像一个庞大的乐队在地上、空中、屋顶上演奏着秋的交响曲!行道树叶——梧桐叶也伴着秋雨在天空中飘荡,像几只飞舞的蝴蝶在天空中嬉戏!终于,它们飘累了,慢慢地落在了湿漉漉的水泥地上。远远的望去,就像是土地上的几朵小花,给寂寞的秋天增添了几分情趣!
表结构:
数据:
需求:
按照company_id不同分组,然后分别求出相同company_id相邻记录touch_time的差值
SQL:
select r1.company_id, r1.touch_time, r2.touch_time, r1.touch_time - r2.touch_time from (select (@rownum := @rownum + 1) as rownum, info.company_id, info.touch_time from sys_touch_info info, (select @rownum := 0) r where info.touch_time is not null order by info.company_id) r1 left join (select (@index := @index + 1) as rownum, info.company_id, info.touch_time from sys_touch_info info, (select @index := 0) r where info.touch_time is not null order by info.company_id) r2 on r1.company_id = r2.company_id and r1.rownum = r2.rownum - 1
结果:
以上这篇Mysql 相邻两行记录某列的差值方法就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持。