Filter zipcodes by proximity in Django with the Spherical Law of Cosines

Question

I\'m trying to handle proximity search for a basic store locater in Django. Rather than haul PostGIS around with my app just so I can use GeoDjango\'s distance filter, I\'d

Answer 1

Following jboxer's response

def find_cars_within_miles_from_postcode(request, miles, postcode=0):

    # create cursor for RAW query
    cursor = connection.cursor()

    # Get lat and lon from google
    lat, lon = getLonLatFromPostcode(postcode)

    # Gen query
    query = "SELECT id, ((ACOS(SIN("+lat+" * PI() / 180) * SIN(lat * PI() / 180) + COS("+lat+" * PI() / 180) * COS(lat * PI() / 180) * COS(("+lon+" - lon) * PI() / 180)) * 180 / PI()) * 60 * 1.1515) AS distance FROM app_car HAVING distance<='"+miles+"' ORDER BY distance ASC"

    # execute the query
    cursor.execute(query)

    # grab all the IDS form the sql result
    ids = [row[0] for row in cursor.fetchall()]

    # find cars from ids
    cars = Car.objects.filter(id__in=ids)

    # return the Cars with these IDS
    return HttpResponse( cars )

This returns my cars from x amount of miles, this works well. However the raw query returned how far they were from a certain location, i think the fieldname was 'distance'.

How can i return this field 'distance' with my car objects?