Spatial Linq query with distance() method

Question

I'm trying to get locations from a SQL Server database which are inside specific radius. It works fine when I use spatial data from database and pass it to the DBGeography.Distance() method. But when i try to pass coordinates to Distance() method like:

var sourcePoint = string.Format("POINT({0} {1})", location.lat.ToString().Replace(',','.'), location.lon.ToString().Replace(',','.'));

var origin = DbGeography.PointFromText(sourcePoint, 4326);

var result = from r in db.Locations
        where r.Coordinates.Distance(origin) <= distanceMeters
        select r;

It returns nothing. Although locations are inside defined radius.

Doing it like this works just fine and able to get locations inside radius:

var person = db.People.Single(p => p.PersonID == 2);           

var stores = from s in db.Stores
         where s.Location.Distance(person.Address) * .00062 <= 1

         select new Location
         {

         Name = s.Name,
         Latitude = s.Location.Latitude,
         Longitude = s.Location.Longitude
         };

I cant wrap my head around why it doesn't work in first example way. :)

Answer 1

It looks like you've got longitude and latitude switched in the WKT for your point. Here's a quick example to demonstrate:

DECLARE @g geography;
SET @g = geography::STPointFromText('POINT(-122.34900 47.65100)', 4326);
SELECT @g.Long, @g.Lat;