create table tb(id int,guestId int,time datetime)
insert into tb values(1 , 1 , '2008-02-03 11:24:16')
insert into tb values(2 , 2 , '2008-02-03 12:24:16')
insert into tb values(3 , 1 , '2008-02-03 10:24:16')
insert into tb values(3 , 1 , '2008-02-03 13:24:16')
goselect t.* from
(
select guestid , max(time) time from tb group by guestid
) t
where datediff(day , time , getdate()) >= 90drop table tb /*
guestid time
----------- ------------------------------------------------------
1 2008-02-03 13:24:16.000
2 2008-02-03 12:24:16.000(所影响的行数为 2 行)*/
insert into tb values(1 , 1 , '2008-02-03 11:24:16')
insert into tb values(2 , 2 , '2008-02-03 12:24:16')
insert into tb values(3 , 1 , '2008-02-03 10:24:16')
insert into tb values(3 , 1 , '2008-02-03 13:24:16')
goselect t.* from
(
select guestid , max(time) time from tb group by guestid
) t
where datediff(day , time , getdate()) >= 90drop table tb /*
guestid time
----------- ------------------------------------------------------
1 2008-02-03 13:24:16.000
2 2008-02-03 12:24:16.000(所影响的行数为 2 行)*/
只得到一个guestid 可以不