从某个点到最近的地方
问题描述：
我有下表
create table places(lat_lng point, place_name varchar(50));
insert into places values (POINT(-126.4, 45.32), 'Food Bar');
要使所有位置都接近特定经度/纬度的查询应该是什么?
What should be the query to get all places close to particular lat/long?
gis已安装.
答
如果您确实想使用PostGIS:
If you actually wanted to use PostGIS:
create table places(
lat_lng geography(Point,4326),
place_name varchar(50)
);
-- Two ways to make a geography point
insert into places values (ST_MakePoint(-126.4, 45.32), 'Food Bar1');
insert into places values ('POINT(-126.4 45.32)', 'Food Bar2');
-- Spatial index
create index places_lat_lng_idx on places using gist(lat_lng);
现在可以找到1公里(或1000 m)以内的所有地点:
Now to find all of the places within 1 km (or 1000 m):
select *, ST_Distance(lat_lng, ST_MakePoint(-126.4, 45.32)::geography)
from places
where ST_DWithin(lat_lng, ST_MakePoint(-126.4, 45.32)::geography, 1000)
order by ST_Distance(lat_lng, ST_MakePoint(-126.4, 45.32)::geography);