Getting all Buildings in range of 5 miles from specified coordinates

问题

I have database table Building with these columns: name, lat, lng

How can I get all Buildings in range of 5 miles from specified coordinates, for example these:

-84.38653999999998

33.72024

My try but it does not work:

SELECT ST_CONTAINS(
  SELECT ST_BUFFER(ST_Point(-84.38653999999998,33.72024), 5), 
  SELECT ST_POINT(lat,lng) FROM "my_db"."Building" LIMIT 50
);

https://docs.aws.amazon.com/athena/latest/ug/geospatial-functions-list.html

回答1:

Why are you storing x,y in separated columns? I would sincerely recommend you to store them as geometry or geography to avoid the casting overhead in query time.

That being said, you can compute the distance in miles using something like this:

(Test data)

CREATE TEMPORARY TABLE building (name text, lat numeric, long numeric);
INSERT INTO building VALUES ('foo',7.52,51.96);
INSERT INTO building VALUES ('bar',7.62,51.94);
INSERT INTO building VALUES ('far away ... ',10.62,59.94);

The function ST_Distance (with geography type parameters) will return the distance in meters. All you have to do is to convert meters to miles in the end. Something like:

SELECT *, ST_Distance(ST_GeographyFromText('POINT(7.62 51.93)'),
      ST_MakePoint(lat,long)) * 0.000621371 AS distance
FROM building
WHERE 
  ST_Distance(ST_GeographyFromText('POINT(7.62 51.93)'),
  ST_MakePoint(lat,long)) * 0.000621371 > 5

     name      |  lat  | long  |     distance     
---------------+-------+-------+------------------
 far away ...  | 10.62 | 59.94 | 566.123267141404
(1 Zeile)

EDIT- Amazon Athena equivalent (distance in degrees):

SELECT *, ST_DISTANCE(ST_GEOMETRY_FROM_TEXT('POINT(-84.386330 33.753746)'),
      ST_POINT(lat,long)) AS distance
FROM building
WHERE 
  ST_Distance(ST_GEOMETRY_FROM_TEXT('POINT(-84.386330 33.753746)'),
  ST_POINT(lat,long)) > 5;

回答2:

First thing first. If possible use Postgis not amazon-athena. Looking on documentation athena looks like the castrated version of a spatial tool.

First - Install postgis.

 CREATE EXTENSION postgis SCHEMA public;

Now create geometry(if you want to use metric SRID like 3857 for example) or geography (if you want use degree SRID like 4326) column for your data.

alter table building add column geog geography;

Then transform your point data (lat,long) data to geometry/geography:

update building
   set geog=(ST_SetSRID(ST_MakePoint(lat,long),4326)::geography)

Next create spatial index on it

create index on buildings using gist(geog);

Now you are ready for action

select *, 
       st_distance(geog, ST_makePoint(-84.386,33.72024))/1609.34 dist_miles
  from building
 where st_dwithin(geog, ST_makePoint(-84.38653999999998,33.72024),5*1609.34);

Few words of explenations: Index is useful if you have many records in your table. ST_Dwithin uses index when st_distance doesn't so ST_dwithin will make your query much faster on big data sets.

来源：https://stackoverflow.com/questions/51889155/getting-all-buildings-in-range-of-5-miles-from-specified-coordinates

标签

sql

postgresql

PostGIS

presto

amazon-athena