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Fixed incomplete merge of geographic aggregates; added support for `Extent` aggregate to Oracle spatial backend. Refs #3566. 

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9748 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Justin Bronn 2009-01-15 19:35:04 +00:00
parent 91e25f9ef8
commit f671a5c961
7 changed files with 115 additions and 51 deletions
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3
django/contrib/gis/db/models/__init__.py
View File

@ -1,6 +1,9 @@
# Want to get everything from the 'normal' models package.
from django.db.models import *
# Geographic aggregate functions
from django.contrib.gis.db.models.aggregates import *
# The GeoManager
from django.contrib.gis.db.models.manager import GeoManager

24
django/contrib/gis/db/models/aggregates.py
View File

@ -1,10 +1,28 @@
from django.db.models import Aggregate
from django.contrib.gis.db.backend import SpatialBackend
from django.contrib.gis.db.models.sql import GeomField
class Extent(Aggregate):
class GeoAggregate(Aggregate):
def add_to_query(self, query, alias, col, source, is_summary):
if hasattr(source, '_geom'):
# Doing additional setup on the Query object for spatial aggregates.
aggregate = getattr(query.aggregates_module, self.name)
# Adding a conversion class instance and any selection wrapping
# SQL (e.g., needed by Oracle).
if aggregate.conversion_class is GeomField:
query.extra_select_fields[alias] = GeomField()
if SpatialBackend.select:
query.custom_select[alias] = SpatialBackend.select
super(GeoAggregate, self).add_to_query(query, alias, col, source, is_summary)
class Extent(GeoAggregate):
name = 'Extent'
class MakeLine(Aggregate):
class MakeLine(GeoAggregate):
name = 'MakeLine'
class Union(Aggregate):
class Union(GeoAggregate):
name = 'Union'

3
django/contrib/gis/db/models/query.py
View File

@ -8,7 +8,6 @@ from django.contrib.gis.db.models.fields import GeometryField, PointField
from django.contrib.gis.db.models.sql import AreaField, DistanceField, GeomField, GeoQuery, GeoWhereNode
from django.contrib.gis.measure import Area, Distance
from django.contrib.gis.models import get_srid_info
qn = connection.ops.quote_name
# For backwards-compatibility; Q object should work just fine
# after queryset-refactor.
@ -331,7 +330,7 @@ class GeoQuerySet(QuerySet):
if SpatialBackend.oracle: agg_kwargs['tolerance'] = tolerance
# Calling the QuerySet.aggregate, and returning only the value of the aggregate.
return self.aggregate(_geoagg=aggregate(agg_col, **agg_kwargs))['_geoagg']
return self.aggregate(geoagg=aggregate(agg_col, **agg_kwargs))['geoagg']
def _spatial_attribute(self, att, settings, field_name=None, model_att=None):
"""

3
django/contrib/gis/db/models/sql/__init__.py
View File

@ -1,2 +1,3 @@
from django.contrib.gis.db.models.sql.query import AreaField, DistanceField, GeomField, GeoQuery
from django.contrib.gis.db.models.sql.conversion import AreaField, DistanceField, GeomField
from django.contrib.gis.db.models.sql.query import GeoQuery
from django.contrib.gis.db.models.sql.where import GeoWhereNode

61
django/contrib/gis/db/models/sql/aggregates.py
View File

@ -1,22 +1,68 @@
from django.db.models.sql.aggregates import *
from django.contrib.gis.db.models.fields import GeometryField
from django.contrib.gis.db.models.sql.conversion import GeomField
from django.contrib.gis.db.backend import SpatialBackend
if SpatialBackend.oracle:
# Default SQL template for spatial aggregates.
geo_template = '%(function)s(%(field)s)'
# Default conversion functions for aggregates; will be overridden if implemented
# for the spatial backend.
def convert_extent(box):
raise NotImplementedError('Aggregate extent not implemented for this spatial backend.')
def convert_geom(wkt, geo_field):
raise NotImplementedError('Aggregate method not implemented for this spatial backend.')
if SpatialBackend.postgis:
def convert_extent(box):
# Box text will be something like "BOX(-90.0 30.0, -85.0 40.0)";
# parsing out and returning as a 4-tuple.
ll, ur = box[4:-1].split(',')
xmin, ymin = map(float, ll.split())
xmax, ymax = map(float, ur.split())
return (xmin, ymin, xmax, ymax)
def convert_geom(hex, geo_field):
if hex: return SpatialBackend.Geometry(hex)
else: return None
elif SpatialBackend.oracle:
# Oracle spatial aggregates need a tolerance.
geo_template = '%(function)s(SDOAGGRTYPE(%(field)s,%(tolerance)s))'
else:
geo_template = '%(function)s(%(field)s)'
def convert_extent(clob):
if clob:
# Oracle returns a polygon for the extent, we construct
# the 4-tuple from the coordinates in the polygon.
poly = SpatialBackend.Geometry(clob.read())
shell = poly.shell
ll, ur = shell[0], shell[2]
xmin, ymin = ll
xmax, ymax = ur
return (xmin, ymin, xmax, ymax)
else:
return None
def convert_geom(clob, geo_field):
if clob: return SpatialBackend.Geometry(clob.read(), geo_field._srid)
else: return None
class GeoAggregate(Aggregate):
# Overriding the SQL template with the geographic one.
sql_template = geo_template
# Conversion class, if necessary.
conversion_class = None
# Flags for indicating the type of the aggregate.
is_extent = False
def __init__(self, col, source=None, is_summary=False, **extra):
super(GeoAggregate, self).__init__(col, source, is_summary, **extra)
if not self.is_extent and SpatialBackend.oracle:
self.extra.setdefault('tolerance', 0.05)
# Can't use geographic aggregates on non-geometry fields.
if not isinstance(self.source, GeometryField):
raise ValueError('Geospatial aggregates only allowed on geometry fields.')
@ -29,8 +75,15 @@ class Extent(GeoAggregate):
is_extent = True
sql_function = SpatialBackend.extent
if SpatialBackend.oracle:
# Have to change Extent's attributes here for Oracle.
Extent.conversion_class = GeomField
Extent.sql_template = '%(function)s(%(field)s)'
class MakeLine(GeoAggregate):
conversion_class = GeomField
sql_function = SpatialBackend.make_line
class Union(GeoAggregate):
conversion_class = GeomField
sql_function = SpatialBackend.unionagg

25
django/contrib/gis/db/models/sql/conversion.py Normal file
View File

@ -0,0 +1,25 @@
"""
This module holds simple classes used by GeoQuery.convert_values
to convert geospatial values from the database.
"""
class BaseField(object):
def get_internal_type(self):
"Overloaded method so OracleQuery.convert_values doesn't balk."
return None
class AreaField(BaseField):
"Wrapper for Area values."
def __init__(self, area_att):
self.area_att = area_att
class DistanceField(BaseField):
"Wrapper for Distance values."
def __init__(self, distance_att):
self.distance_att = distance_att
class GeomField(BaseField):
"""
Wrapper for Geometry values. It is a lightweight alternative to
using GeometryField (which requires a SQL query upon instantiation).
"""
pass

45
django/contrib/gis/db/models/sql/query.py
View File

@ -6,6 +6,7 @@ from django.db.models.fields.related import ForeignKey
from django.contrib.gis.db.backend import SpatialBackend
from django.contrib.gis.db.models.fields import GeometryField
from django.contrib.gis.db.models.sql import aggregates as gis_aggregates_module
from django.contrib.gis.db.models.sql.conversion import AreaField, DistanceField, GeomField
from django.contrib.gis.db.models.sql.where import GeoWhereNode
from django.contrib.gis.measure import Area, Distance
@ -13,28 +14,6 @@ from django.contrib.gis.measure import Area, Distance
ALL_TERMS = sql.constants.QUERY_TERMS.copy()
ALL_TERMS.update(SpatialBackend.gis_terms)
# Conversion functions used in normalizing geographic aggregates.
if SpatialBackend.postgis:
def convert_extent(box):
# TODO: Parsing of BOX3D, Oracle support (patches welcome!)
# Box text will be something like "BOX(-90.0 30.0, -85.0 40.0)";
# parsing out and returning as a 4-tuple.
ll, ur = box[4:-1].split(',')
xmin, ymin = map(float, ll.split())
xmax, ymax = map(float, ur.split())
return (xmin, ymin, xmax, ymax)
def convert_geom(hex, geo_field):
if hex: return SpatialBackend.Geometry(hex)
else: return None
else:
def convert_extent(box):
raise NotImplementedError('Aggregate extent not implemented for this spatial backend.')
def convert_geom(clob, geo_field):
if clob: return SpatialBackend.Geometry(clob.read(), geo_field._srid)
else: return None
class GeoQuery(sql.Query):
"""
A single spatial SQL query.
@ -118,7 +97,7 @@ class GeoQuery(sql.Query):
result.extend([
'%s%s' % (
aggregate.as_sql(quote_func=qn),
self.get_extra_select_format(alias) % aggregate.as_sql(quote_func=qn),
alias is not None and ' AS %s' % alias or ''
)
for alias, aggregate in self.aggregate_select.items()
@ -228,7 +207,7 @@ class GeoQuery(sql.Query):
"""
if SpatialBackend.oracle:
# Running through Oracle's first.
value = super(GeoQuery, self).convert_values(value, field)
value = super(GeoQuery, self).convert_values(value, field or GeomField())
if isinstance(field, DistanceField):
# Using the field's distance attribute, can instantiate
# `Distance` with the right context.
@ -246,9 +225,9 @@ class GeoQuery(sql.Query):
"""
if isinstance(aggregate, self.aggregates_module.GeoAggregate):
if aggregate.is_extent:
return convert_extent(value)
return self.aggregates_module.convert_extent(value)
else:
return convert_geom(value, aggregate.source)
return self.aggregates_module.convert_geom(value, aggregate.source)
else:
return super(GeoQuery, self).resolve_aggregate(value, aggregate)
@ -361,17 +340,3 @@ class GeoQuery(sql.Query):
# Otherwise, check by the given field name -- which may be
# a lookup to a _related_ geographic field.
return self._check_geo_field(self.model, field_name)
### Field Classes for `convert_values` ####
class AreaField(object):
def __init__(self, area_att):
self.area_att = area_att
class DistanceField(object):
def __init__(self, distance_att):
self.distance_att = distance_att
# Rather than use GeometryField (which requires a SQL query
# upon instantiation), use this lighter weight class.
class GeomField(object):
pass