select a.id,a.name,bb.dt from a right join (select *from (select max(login_date) as dt,a_id from b group by a_id) as c where c.dt<'2006-9-3') as bb on a.id=bb.a_id
select id name from a left join b on a.id=b.a_id where TO_DAYS(NOW()) - TO_DAYS(login_date) > 10; 不知道行不行...
select a.id,a.name from a left join b on a.id=b.a_id group by a.id having to_days(now())-to_days(max(b.login_date))>10
select a.name,b.a_id from a inner join b on a.id=b.a_id where date()-login_date>10
不知道行不行...