select * from tb a where not exists ( select 1 from tb b where 1=1 and b.returntime < a.returntime and abs(b.lat - a.lat) < 0.1 )
select a.id,a.lat,a.lng,a.image,a.returntime from tb a (nolock) left outer join tb b(nolock) on a.returntime<b.returntime where abs(a.lat-isnull(b.lat,a.lat))<0.1 group by a.id,a.lat,a.lng,a.image,a.returntime order by a.returntime试试这样的写法
from tb a
where not exists (
select 1
from tb b
where 1=1
and b.returntime < a.returntime
and abs(b.lat - a.lat) < 0.1
)
from tb a (nolock) left outer join tb b(nolock) on a.returntime<b.returntime
where abs(a.lat-isnull(b.lat,a.lat))<0.1
group by a.id,a.lat,a.lng,a.image,a.returntime
order by a.returntime试试这样的写法