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Revision 7641, 0.9 kB
(checked in by jbronn, 4 months ago)
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gis: Refactor of the GeoQuerySet; new features include:
(1) Creation of internal API that eases generation of GeoQuerySet methods.
(2) GeoQuerySet.distance now returns Distance objects instead of floats.
(3) Added the new GeoQuerySet methods: area, centroid, difference, envelope, intersection, length, make_line, mem_size, num_geom, num_points, perimeter, point_on_surface, scale, svg, sym_difference, translate, union.
(4) The model_att keyword may be used to customize the attribute that GeoQuerySet methods attach output to.
(5) Geographic distance lookups and GeoQuerySet.distance calls now use ST_distance_sphere by default (performance benefits far outweigh small loss in accuracy); ST_distance_spheroid may still be used by specifying an option.
(6) GeoQuerySet methods may now operate accross ForeignKey? relations specified via the field_name keyword (but this does not work on Oracle).
(7) Area now has the same units of measure as Distance.
Backward Incompatibilites:
- The aggregate union method is now known as unionagg.
- The field_name keyword used for GeoQuerySet methods may no longer be specified via positional arguments.
- Distance objects returned instead of floats from GeoQuerySet.distance.
- ST_Distance_sphere used by default for geographic distance calculations.
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""" |
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This module provides the backend for spatial SQL construction with Django. |
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Specifically, this module will import the correct routines and modules |
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needed for GeoDjango to interface with the spatial database. |
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""" |
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from django.conf import settings |
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from django.contrib.gis.db.backend.util import gqn |
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# Retrieving the necessary settings from the backend. |
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if settings.DATABASE_ENGINE == 'postgresql_psycopg2': |
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from django.contrib.gis.db.backend.postgis import create_spatial_db, get_geo_where_clause, SpatialBackend |
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elif settings.DATABASE_ENGINE == 'oracle': |
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from django.contrib.gis.db.backend.oracle import create_spatial_db, get_geo_where_clause, SpatialBackend |
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elif settings.DATABASE_ENGINE == 'mysql': |
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from django.contrib.gis.db.backend.mysql import create_spatial_db, get_geo_where_clause, SpatialBackend |
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else: |
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raise NotImplementedError('No Geographic Backend exists for %s' % settings.DATABASE_ENGINE) |
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