id userid datecreate table tmp(id int not null auto_increment primary key,userid,date); insert itno tmp(userid,date) select userid,date from tb order by userid,id;create table tmp2(a int,b.userid,c date) insert into tmp2,select A.id,A.userid,timestampdiff(HOUR,A.date,B.date) from tmp A,tmp B where A.userid=B.userid and A.id=B.id-1select userid,date from tmp2 A where not exists(select 1 from temp2 where A.userid=userid and A.id>id)
insert itno tmp(userid,date) select userid,date from tb order by userid,id;create table tmp2(a int,b.userid,c date)
insert into tmp2,select A.id,A.userid,timestampdiff(HOUR,A.date,B.date) from tmp A,tmp B where A.userid=B.userid and A.id=B.id-1select userid,date from tmp2 A
where not exists(select 1 from temp2 where A.userid=userid and A.id>id)
参考一下这个贴子的提问方式http://bbs.csdn.net/topics/320211382
1. 你的 create table xxx .. 语句
2. 你的 insert into xxx ... 语句
3. 结果是什么样,(并给以简单的算法描述)
4. 你用的数据库名称和版本(经常有人在MS SQL server版问 MySQL)
这样想帮你的人可以直接搭建和你相同的环境,并在给出方案前进行测试,避免文字描述理解上的误差。