52 lines
2.1 KiB
Python
52 lines
2.1 KiB
Python
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from django.contrib.gis.gdal import OGRGeomType
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from django.db.backends.sqlite3.introspection import DatabaseIntrospection, FlexibleFieldLookupDict
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class GeoFlexibleFieldLookupDict(FlexibleFieldLookupDict):
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"""
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Sublcass that includes updates the `base_data_types_reverse` dict
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for geometry field types.
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"""
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base_data_types_reverse = FlexibleFieldLookupDict.base_data_types_reverse.copy()
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base_data_types_reverse.update(
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{'point' : 'GeometryField',
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'linestring' : 'GeometryField',
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'polygon' : 'GeometryField',
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'multipoint' : 'GeometryField',
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'multilinestring' : 'GeometryField',
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'multipolygon' : 'GeometryField',
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'geometrycollection' : 'GeometryField',
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})
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class SpatiaLiteIntrospection(DatabaseIntrospection):
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data_types_reverse = GeoFlexibleFieldLookupDict()
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def get_geometry_type(self, table_name, geo_col):
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cursor = self.connection.cursor()
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try:
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# Querying the `geometry_columns` table to get additional metadata.
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cursor.execute('SELECT "coord_dimension", "srid", "type" '
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'FROM "geometry_columns" '
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'WHERE "f_table_name"=%s AND "f_geometry_column"=%s',
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(table_name, geo_col))
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row = cursor.fetchone()
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if not row:
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raise Exception('Could not find a geometry column for "%s"."%s"' %
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(table_name, geo_col))
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# OGRGeomType does not require GDAL and makes it easy to convert
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# from OGC geom type name to Django field.
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field_type = OGRGeomType(row[2]).django
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# Getting any GeometryField keyword arguments that are not the default.
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dim = row[0]
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srid = row[1]
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field_params = {}
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if srid != 4326:
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field_params['srid'] = srid
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if isinstance(dim, basestring) and 'Z' in dim:
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field_params['dim'] = 3
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finally:
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cursor.close()
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return field_type, field_params
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