Enabled area calculations for geography columns.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14189 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Justin Bronn 2010-10-12 17:13:27 +00:00
parent c7384af061
commit 120aae2209
4 changed files with 14 additions and 3 deletions

View File

@ -48,7 +48,10 @@ class GeoQuerySet(QuerySet):
s['procedure_args']['tolerance'] = tolerance
s['select_field'] = AreaField('sq_m') # Oracle returns area in units of meters.
elif backend.postgis or backend.spatialite:
if not geo_field.geodetic(connection):
if backend.geography:
# Geography fields support area calculation, returns square meters.
s['select_field'] = AreaField('sq_m')
elif not geo_field.geodetic(connection):
# Getting the area units of the geographic field.
s['select_field'] = AreaField(Area.unit_attname(geo_field.units_name(connection)))
else:

View File

@ -10,7 +10,7 @@ class Zipcode(models.Model):
code = models.CharField(max_length=10)
poly = models.PolygonField(geography=True)
objects = models.GeoManager()
def __unicode__(self): return self.name
def __unicode__(self): return self.code
class County(models.Model):
name = models.CharField(max_length=25)

View File

@ -76,3 +76,12 @@ class GeographyTest(TestCase):
self.assertEqual(num_poly, len(c.mpoly))
self.assertEqual(name, c.name)
self.assertEqual(state, c.state)
def test06_geography_area(self):
"Testing that Area calculations work on geography columns."
from django.contrib.gis.measure import A
# SELECT ST_Area(poly) FROM geogapp_zipcode WHERE code='77002';
ref_area = 5439084.70637573
tol = 5
z = Zipcode.objects.area().get(code='77002')
self.assertAlmostEqual(z.area.sq_m, ref_area, tol)

View File

@ -216,7 +216,6 @@ only the following additional :ref:`spatial lookups <spatial-lookups>` are
available for geography columns:
* :lookup:`bboverlaps`
* :lookup:`exact`, and :lookup:`same_as`
* :lookup:`coveredby`
* :lookup:`covers`
* :lookup:`intersects`