py_tasks_melange: comparison app/django/contrib/gis/db/models/query.py

equal deleted inserted replaced

-:6641e941ef1e
+:ff1a9aa48cfd
+from django.core.exceptions import ImproperlyConfigured
+from django.db import connection
+from django.db.models.query import sql, QuerySet, Q
+from django.contrib.gis.db.backend import SpatialBackend
+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.
+class GeoQ(Q): pass
+class GeomSQL(object):
+"Simple wrapper object for geometric SQL."
+def __init__(self, geo_sql):
+self.sql = geo_sql
+def as_sql(self, *args, **kwargs):
+return self.sql
+class GeoQuerySet(QuerySet):
+"The Geographic QuerySet."
+def __init__(self, model=None, query=None):
+super(GeoQuerySet, self).__init__(model=model, query=query)
+self.query = query or GeoQuery(self.model, connection)
+def area(self, tolerance=0.05, **kwargs):
+"""
+Returns the area of the geographic field in an `area` attribute on
+each element of this GeoQuerySet.
+"""
+# Peforming setup here rather than in `_spatial_attribute` so that
+# we can get the units for `AreaField`.
+procedure_args, geo_field = self._spatial_setup('area', field_name=kwargs.get('field_name', None))
+s = {'procedure_args' : procedure_args,
+'geo_field' : geo_field,
+'setup' : False,
+}
+if SpatialBackend.oracle:
+s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
+s['procedure_args']['tolerance'] = tolerance
+s['select_field'] = AreaField('sq_m') # Oracle returns area in units of meters.
+elif SpatialBackend.postgis:
+if not geo_field.geodetic:
+# Getting the area units of the geographic field.
+s['select_field'] = AreaField(Area.unit_attname(geo_field._unit_name))
+else:
+# TODO: Do we want to support raw number areas for geodetic fields?
+raise Exception('Area on geodetic coordinate systems not supported.')
+return self._spatial_attribute('area', s, **kwargs)
+def centroid(self, **kwargs):
+"""
+Returns the centroid of the geographic field in a `centroid`
+attribute on each element of this GeoQuerySet.
+"""
+return self._geom_attribute('centroid', **kwargs)
+def difference(self, geom, **kwargs):
+"""
+Returns the spatial difference of the geographic field in a `difference`
+attribute on each element of this GeoQuerySet.
+"""
+return self._geomset_attribute('difference', geom, **kwargs)
+def distance(self, geom, **kwargs):
+"""
+Returns the distance from the given geographic field name to the
+given geometry in a `distance` attribute on each element of the
+GeoQuerySet.
+Keyword Arguments:
+`spheroid`  => If the geometry field is geodetic and PostGIS is
+the spatial database, then the more accurate
+spheroid calculation will be used instead of the
+quicker sphere calculation.
+`tolerance` => Used only for Oracle. The tolerance is
+in meters -- a default of 5 centimeters (0.05)
+is used.
+"""
+return self._distance_attribute('distance', geom, **kwargs)
+def envelope(self, **kwargs):
+"""
+Returns a Geometry representing the bounding box of the
+Geometry field in an `envelope` attribute on each element of
+the GeoQuerySet.
+"""
+return self._geom_attribute('envelope', **kwargs)
+def extent(self, **kwargs):
+"""
+Returns the extent (aggregate) of the features in the GeoQuerySet.  The
+extent will be returned as a 4-tuple, consisting of (xmin, ymin, xmax, ymax).
+"""
+convert_extent = None
+if SpatialBackend.postgis:
+def convert_extent(box, geo_field):
+# 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)
+elif SpatialBackend.oracle:
+def convert_extent(wkt, geo_field):
+raise NotImplementedError
+return self._spatial_aggregate('extent', convert_func=convert_extent, **kwargs)
+def gml(self, precision=8, version=2, **kwargs):
+"""
+Returns GML representation of the given field in a `gml` attribute
+on each element of the GeoQuerySet.
+"""
+s = {'desc' : 'GML', 'procedure_args' : {'precision' : precision}}
+if SpatialBackend.postgis:
+# PostGIS AsGML() aggregate function parameter order depends on the
+# version -- uggh.
+major, minor1, minor2 = SpatialBackend.version
+if major >= 1 and (minor1 > 3 or (minor1 == 3 and minor2 > 1)):
+procedure_fmt = '%(version)s,%(geo_col)s,%(precision)s'
+else:
+procedure_fmt = '%(geo_col)s,%(precision)s,%(version)s'
+s['procedure_args'] = {'precision' : precision, 'version' : version}
+return self._spatial_attribute('gml', s, **kwargs)
+def intersection(self, geom, **kwargs):
+"""
+Returns the spatial intersection of the Geometry field in
+an `intersection` attribute on each element of this
+GeoQuerySet.
+"""
+return self._geomset_attribute('intersection', geom, **kwargs)
+def kml(self, **kwargs):
+"""
+Returns KML representation of the geometry field in a `kml`
+attribute on each element of this GeoQuerySet.
+"""
+s = {'desc' : 'KML',
+'procedure_fmt' : '%(geo_col)s,%(precision)s',
+'procedure_args' : {'precision' : kwargs.pop('precision', 8)},
+}
+return self._spatial_attribute('kml', s, **kwargs)
+def length(self, **kwargs):
+"""
+Returns the length of the geometry field as a `Distance` object
+stored in a `length` attribute on each element of this GeoQuerySet.
+"""
+return self._distance_attribute('length', None, **kwargs)
+def make_line(self, **kwargs):
+"""
+Creates a linestring from all of the PointField geometries in the
+this GeoQuerySet and returns it.  This is a spatial aggregate
+method, and thus returns a geometry rather than a GeoQuerySet.
+"""
+kwargs['geo_field_type'] = PointField
+kwargs['agg_field'] = GeometryField
+return self._spatial_aggregate('make_line', **kwargs)
+def mem_size(self, **kwargs):
+"""
+Returns the memory size (number of bytes) that the geometry field takes
+in a `mem_size` attribute  on each element of this GeoQuerySet.
+"""
+return self._spatial_attribute('mem_size', {}, **kwargs)
+def num_geom(self, **kwargs):
+"""
+Returns the number of geometries if the field is a
+GeometryCollection or Multi* Field in a `num_geom`
+attribute on each element of this GeoQuerySet; otherwise
+the sets with None.
+"""
+return self._spatial_attribute('num_geom', {}, **kwargs)
+def num_points(self, **kwargs):
+"""
+Returns the number of points in the first linestring in the
+Geometry field in a `num_points` attribute on each element of
+this GeoQuerySet; otherwise sets with None.
+"""
+return self._spatial_attribute('num_points', {}, **kwargs)
+def perimeter(self, **kwargs):
+"""
+Returns the perimeter of the geometry field as a `Distance` object
+stored in a `perimeter` attribute on each element of this GeoQuerySet.
+"""
+return self._distance_attribute('perimeter', None, **kwargs)
+def point_on_surface(self, **kwargs):
+"""
+Returns a Point geometry guaranteed to lie on the surface of the
+Geometry field in a `point_on_surface` attribute on each element
+of this GeoQuerySet; otherwise sets with None.
+"""
+return self._geom_attribute('point_on_surface', **kwargs)
+def scale(self, x, y, z=0.0, **kwargs):
+"""
+Scales the geometry to a new size by multiplying the ordinates
+with the given x,y,z scale factors.
+"""
+s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
+'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
+'select_field' : GeomField(),
+}
+return self._spatial_attribute('scale', s, **kwargs)
+def svg(self, **kwargs):
+"""
+Returns SVG representation of the geographic field in a `svg`
+attribute on each element of this GeoQuerySet.
+"""
+s = {'desc' : 'SVG',
+'procedure_fmt' : '%(geo_col)s,%(rel)s,%(precision)s',
+'procedure_args' : {'rel' : int(kwargs.pop('relative', 0)),
+'precision' : kwargs.pop('precision', 8)},
+}
+return self._spatial_attribute('svg', s, **kwargs)
+def sym_difference(self, geom, **kwargs):
+"""
+Returns the symmetric difference of the geographic field in a
+`sym_difference` attribute on each element of this GeoQuerySet.
+"""
+return self._geomset_attribute('sym_difference', geom, **kwargs)
+def translate(self, x, y, z=0.0, **kwargs):
+"""
+Translates the geometry to a new location using the given numeric
+parameters as offsets.
+"""
+s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
+'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
+'select_field' : GeomField(),
+}
+return self._spatial_attribute('translate', s, **kwargs)
+def transform(self, srid=4326, **kwargs):
+"""
+Transforms the given geometry field to the given SRID.  If no SRID is
+provided, the transformation will default to using 4326 (WGS84).
+"""
+if not isinstance(srid, (int, long)):
+raise TypeError('An integer SRID must be provided.')
+field_name = kwargs.get('field_name', None)
+tmp, geo_field = self._spatial_setup('transform', field_name=field_name)
+# Getting the selection SQL for the given geographic field.
+field_col = self._geocol_select(geo_field, field_name)
+# Why cascading substitutions? Because spatial backends like
+# Oracle and MySQL already require a function call to convert to text, thus
+# when there's also a transformation we need to cascade the substitutions.
+# For example, 'SDO_UTIL.TO_WKTGEOMETRY(SDO_CS.TRANSFORM( ... )'
+geo_col = self.query.custom_select.get(geo_field, field_col)
+# Setting the key for the field's column with the custom SELECT SQL to
+# override the geometry column returned from the database.
+custom_sel = '%s(%s, %s)' % (SpatialBackend.transform, geo_col, srid)
+# TODO: Should we have this as an alias?
+# custom_sel = '(%s(%s, %s)) AS %s' % (SpatialBackend.transform, geo_col, srid, qn(geo_field.name))
+self.query.transformed_srid = srid # So other GeoQuerySet methods
+self.query.custom_select[geo_field] = custom_sel
+return self._clone()
+def union(self, geom, **kwargs):
+"""
+Returns the union of the geographic field with the given
+Geometry in a `union` attribute on each element of this GeoQuerySet.
+"""
+return self._geomset_attribute('union', geom, **kwargs)
+def unionagg(self, **kwargs):
+"""
+Performs an aggregate union on the given geometry field.  Returns
+None if the GeoQuerySet is empty.  The `tolerance` keyword is for
+Oracle backends only.
+"""
+kwargs['agg_field'] = GeometryField
+return self._spatial_aggregate('unionagg', **kwargs)
+### Private API -- Abstracted DRY routines. ###
+def _spatial_setup(self, att, aggregate=False, desc=None, field_name=None, geo_field_type=None):
+"""
+Performs set up for executing the spatial function.
+"""
+# Does the spatial backend support this?
+func = getattr(SpatialBackend, att, False)
+if desc is None: desc = att
+if not func: raise ImproperlyConfigured('%s stored procedure not available.' % desc)
+# Initializing the procedure arguments.
+procedure_args = {'function' : func}
+# Is there a geographic field in the model to perform this
+# operation on?
+geo_field = self.query._geo_field(field_name)
+if not geo_field:
+raise TypeError('%s output only available on GeometryFields.' % func)
+# If the `geo_field_type` keyword was used, then enforce that
+# type limitation.
+if not geo_field_type is None and not isinstance(geo_field, geo_field_type):
+raise TypeError('"%s" stored procedures may only be called on %ss.' % (func, geo_field_type.__name__))
+# Setting the procedure args.
+procedure_args['geo_col'] = self._geocol_select(geo_field, field_name, aggregate)
+return procedure_args, geo_field
+def _spatial_aggregate(self, att, field_name=None,
+agg_field=None, convert_func=None,
+geo_field_type=None, tolerance=0.0005):
+"""
+DRY routine for calling aggregate spatial stored procedures and
+returning their result to the caller of the function.
+"""
+# Constructing the setup keyword arguments.
+setup_kwargs = {'aggregate' : True,
+'field_name' : field_name,
+'geo_field_type' : geo_field_type,
+}
+procedure_args, geo_field = self._spatial_setup(att, **setup_kwargs)
+if SpatialBackend.oracle:
+procedure_args['tolerance'] = tolerance
+# Adding in selection SQL for Oracle geometry columns.
+if agg_field is GeometryField:
+agg_sql = '%s' % SpatialBackend.select
+else:
+agg_sql = '%s'
+agg_sql =  agg_sql % ('%(function)s(SDOAGGRTYPE(%(geo_col)s,%(tolerance)s))' % procedure_args)
+else:
+agg_sql = '%(function)s(%(geo_col)s)' % procedure_args
+# Wrapping our selection SQL in `GeomSQL` to bypass quoting, and
+# specifying the type of the aggregate field.
+self.query.select = [GeomSQL(agg_sql)]
+self.query.select_fields = [agg_field]
+try:
+# `asql` => not overriding `sql` module.
+asql, params = self.query.as_sql()
+except sql.datastructures.EmptyResultSet:
+return None
+# Getting a cursor, executing the query, and extracting the returned
+# value from the aggregate function.
+cursor = connection.cursor()
+cursor.execute(asql, params)
+result = cursor.fetchone()[0]
+# If the `agg_field` is specified as a GeometryField, then autmatically
+# set up the conversion function.
+if agg_field is GeometryField and not callable(convert_func):
+if SpatialBackend.postgis:
+def convert_geom(hex, geo_field):
+if hex: return SpatialBackend.Geometry(hex)
+else: return None
+elif SpatialBackend.oracle:
+def convert_geom(clob, geo_field):
+if clob: return SpatialBackend.Geometry(clob.read(), geo_field._srid)
+else: return None
+convert_func = convert_geom
+# Returning the callback function evaluated on the result culled
+# from the executed cursor.
+if callable(convert_func):
+return convert_func(result, geo_field)
+else:
+return result
+def _spatial_attribute(self, att, settings, field_name=None, model_att=None):
+"""
+DRY routine for calling a spatial stored procedure on a geometry column
+and attaching its output as an attribute of the model.
+Arguments:
+att:
+The name of the spatial attribute that holds the spatial
+SQL function to call.
+settings:
+Dictonary of internal settings to customize for the spatial procedure.
+Public Keyword Arguments:
+field_name:
+The name of the geographic field to call the spatial
+function on.  May also be a lookup to a geometry field
+as part of a foreign key relation.
+model_att:
+The name of the model attribute to attach the output of
+the spatial function to.
+"""
+# Default settings.
+settings.setdefault('desc', None)
+settings.setdefault('geom_args', ())
+settings.setdefault('geom_field', None)
+settings.setdefault('procedure_args', {})
+settings.setdefault('procedure_fmt', '%(geo_col)s')
+settings.setdefault('select_params', [])
+# Performing setup for the spatial column, unless told not to.
+if settings.get('setup', True):
+default_args, geo_field = self._spatial_setup(att, desc=settings['desc'], field_name=field_name)
+for k, v in default_args.iteritems(): settings['procedure_args'].setdefault(k, v)
+else:
+geo_field = settings['geo_field']
+# The attribute to attach to the model.
+if not isinstance(model_att, basestring): model_att = att
+# Special handling for any argument that is a geometry.
+for name in settings['geom_args']:
+# Using the field's get_db_prep_lookup() to get any needed
+# transformation SQL -- we pass in a 'dummy' `contains` lookup.
+where, params = geo_field.get_db_prep_lookup('contains', settings['procedure_args'][name])
+# Replacing the procedure format with that of any needed
+# transformation SQL.
+old_fmt = '%%(%s)s' % name
+new_fmt = where[0] % '%%s'
+settings['procedure_fmt'] = settings['procedure_fmt'].replace(old_fmt, new_fmt)
+settings['select_params'].extend(params)
+# Getting the format for the stored procedure.
+fmt = '%%(function)s(%s)' % settings['procedure_fmt']
+# If the result of this function needs to be converted.
+if settings.get('select_field', False):
+sel_fld = settings['select_field']
+if isinstance(sel_fld, GeomField) and SpatialBackend.select:
+self.query.custom_select[model_att] = SpatialBackend.select
+self.query.extra_select_fields[model_att] = sel_fld
+# Finally, setting the extra selection attribute with
+# the format string expanded with the stored procedure
+# arguments.
+return self.extra(select={model_att : fmt % settings['procedure_args']},
+select_params=settings['select_params'])
+def _distance_attribute(self, func, geom=None, tolerance=0.05, spheroid=False, **kwargs):
+"""
+DRY routine for GeoQuerySet distance attribute routines.
+"""
+# Setting up the distance procedure arguments.
+procedure_args, geo_field = self._spatial_setup(func, field_name=kwargs.get('field_name', None))
+# If geodetic defaulting distance attribute to meters (Oracle and
+# PostGIS spherical distances return meters).  Otherwise, use the
+# units of the geometry field.
+if geo_field.geodetic:
+dist_att = 'm'
+else:
+dist_att = Distance.unit_attname(geo_field._unit_name)
+# Shortcut booleans for what distance function we're using.
+distance = func == 'distance'
+length = func == 'length'
+perimeter = func == 'perimeter'
+if not (distance or length or perimeter):
+raise ValueError('Unknown distance function: %s' % func)
+# The field's get_db_prep_lookup() is used to get any
+# extra distance parameters.  Here we set up the
+# parameters that will be passed in to field's function.
+lookup_params = [geom or 'POINT (0 0)', 0]
+# If the spheroid calculation is desired, either by the `spheroid`
+# keyword or wehn calculating the length of geodetic field, make
+# sure the 'spheroid' distance setting string is passed in so we
+# get the correct spatial stored procedure.
+if spheroid or (SpatialBackend.postgis and geo_field.geodetic and length):
+lookup_params.append('spheroid')
+where, params = geo_field.get_db_prep_lookup('distance_lte', lookup_params)
+# The `geom_args` flag is set to true if a geometry parameter was
+# passed in.
+geom_args = bool(geom)
+if SpatialBackend.oracle:
+if distance:
+procedure_fmt = '%(geo_col)s,%(geom)s,%(tolerance)s'
+elif length or perimeter:
+procedure_fmt = '%(geo_col)s,%(tolerance)s'
+procedure_args['tolerance'] = tolerance
+else:
+# Getting whether this field is in units of degrees since the field may have
+# been transformed via the `transform` GeoQuerySet method.
+if self.query.transformed_srid:
+u, unit_name, s = get_srid_info(self.query.transformed_srid)
+geodetic = unit_name in geo_field.geodetic_units
+else:
+geodetic = geo_field.geodetic
+if distance:
+if self.query.transformed_srid:
+# Setting the `geom_args` flag to false because we want to handle
+# transformation SQL here, rather than the way done by default
+# (which will transform to the original SRID of the field rather
+#  than to what was transformed to).
+geom_args = False
+procedure_fmt = '%s(%%(geo_col)s, %s)' % (SpatialBackend.transform, self.query.transformed_srid)
+if geom.srid is None or geom.srid == self.query.transformed_srid:
+# If the geom parameter srid is None, it is assumed the coordinates
+# are in the transformed units.  A placeholder is used for the
+# geometry parameter.
+procedure_fmt += ', %%s'
+else:
+# We need to transform the geom to the srid specified in `transform()`,
+# so wrapping the geometry placeholder in transformation SQL.
+procedure_fmt += ', %s(%%%%s, %s)' % (SpatialBackend.transform, self.query.transformed_srid)
+else:
+# `transform()` was not used on this GeoQuerySet.
+procedure_fmt  = '%(geo_col)s,%(geom)s'
+if geodetic:
+# Spherical distance calculation is needed (because the geographic
+# field is geodetic). However, the PostGIS ST_distance_sphere/spheroid()
+# procedures may only do queries from point columns to point geometries
+# some error checking is required.
+if not isinstance(geo_field, PointField):
+raise TypeError('Spherical distance calculation only supported on PointFields.')
+if not str(SpatialBackend.Geometry(buffer(params[0].wkb)).geom_type) == 'Point':
+raise TypeError('Spherical distance calculation only supported with Point Geometry parameters')
+# The `function` procedure argument needs to be set differently for
+# geodetic distance calculations.
+if spheroid:
+# Call to distance_spheroid() requires spheroid param as well.
+procedure_fmt += ',%(spheroid)s'
+procedure_args.update({'function' : SpatialBackend.distance_spheroid, 'spheroid' : where[1]})
+else:
+procedure_args.update({'function' : SpatialBackend.distance_sphere})
+elif length or perimeter:
+procedure_fmt = '%(geo_col)s'
+if geodetic and length:
+# There's no `length_sphere`
+procedure_fmt += ',%(spheroid)s'
+procedure_args.update({'function' : SpatialBackend.length_spheroid, 'spheroid' : where[1]})
+# Setting up the settings for `_spatial_attribute`.
+s = {'select_field' : DistanceField(dist_att),
+'setup' : False,
+'geo_field' : geo_field,
+'procedure_args' : procedure_args,
+'procedure_fmt' : procedure_fmt,
+}
+if geom_args:
+s['geom_args'] = ('geom',)
+s['procedure_args']['geom'] = geom
+elif geom:
+# The geometry is passed in as a parameter because we handled
+# transformation conditions in this routine.
+s['select_params'] = [SpatialBackend.Adaptor(geom)]
+return self._spatial_attribute(func, s, **kwargs)
+def _geom_attribute(self, func, tolerance=0.05, **kwargs):
+"""
+DRY routine for setting up a GeoQuerySet method that attaches a
+Geometry attribute (e.g., `centroid`, `point_on_surface`).
+"""
+s = {'select_field' : GeomField(),}
+if SpatialBackend.oracle:
+s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
+s['procedure_args'] = {'tolerance' : tolerance}
+return self._spatial_attribute(func, s, **kwargs)
+def _geomset_attribute(self, func, geom, tolerance=0.05, **kwargs):
+"""
+DRY routine for setting up a GeoQuerySet method that attaches a
+Geometry attribute and takes a Geoemtry parameter.  This is used
+for geometry set-like operations (e.g., intersection, difference,
+union, sym_difference).
+"""
+s = {'geom_args' : ('geom',),
+'select_field' : GeomField(),
+'procedure_fmt' : '%(geo_col)s,%(geom)s',
+'procedure_args' : {'geom' : geom},
+}
+if SpatialBackend.oracle:
+s['procedure_fmt'] += ',%(tolerance)s'
+s['procedure_args']['tolerance'] = tolerance
+return self._spatial_attribute(func, s, **kwargs)
+def _geocol_select(self, geo_field, field_name, aggregate=False):
+"""
+Helper routine for constructing the SQL to select the geographic
+column.  Takes into account if the geographic field is in a
+ForeignKey relation to the current model.
+"""
+# If this is an aggregate spatial query, the flag needs to be
+# set on the `GeoQuery` object of this queryset.
+if aggregate: self.query.aggregate = True
+# Is this operation going to be on a related geographic field?
+if not geo_field in self.model._meta.fields:
+# If so, it'll have to be added to the select related information
+# (e.g., if 'location__point' was given as the field name).
+self.query.add_select_related([field_name])
+self.query.pre_sql_setup()
+rel_table, rel_col = self.query.related_select_cols[self.query.related_select_fields.index(geo_field)]
+return self.query._field_column(geo_field, rel_table)
+else:
+return self.query._field_column(geo_field)