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1 from django.contrib.gis.gdal import OGRGeomType |
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2 from django.db.backends.sqlite3.introspection import DatabaseIntrospection, FlexibleFieldLookupDict |
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3 |
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4 class GeoFlexibleFieldLookupDict(FlexibleFieldLookupDict): |
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5 """ |
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6 Sublcass that includes updates the `base_data_types_reverse` dict |
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7 for geometry field types. |
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8 """ |
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9 base_data_types_reverse = FlexibleFieldLookupDict.base_data_types_reverse.copy() |
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10 base_data_types_reverse.update( |
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11 {'point' : 'GeometryField', |
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12 'linestring' : 'GeometryField', |
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13 'polygon' : 'GeometryField', |
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14 'multipoint' : 'GeometryField', |
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15 'multilinestring' : 'GeometryField', |
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16 'multipolygon' : 'GeometryField', |
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17 'geometrycollection' : 'GeometryField', |
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18 }) |
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19 |
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20 class SpatiaLiteIntrospection(DatabaseIntrospection): |
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21 data_types_reverse = GeoFlexibleFieldLookupDict() |
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22 |
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23 def get_geometry_type(self, table_name, geo_col): |
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24 cursor = self.connection.cursor() |
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25 try: |
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26 # Querying the `geometry_columns` table to get additional metadata. |
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27 cursor.execute('SELECT "coord_dimension", "srid", "type" ' |
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28 'FROM "geometry_columns" ' |
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29 'WHERE "f_table_name"=%s AND "f_geometry_column"=%s', |
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30 (table_name, geo_col)) |
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31 row = cursor.fetchone() |
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32 if not row: |
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33 raise Exception('Could not find a geometry column for "%s"."%s"' % |
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34 (table_name, geo_col)) |
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35 |
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36 # OGRGeomType does not require GDAL and makes it easy to convert |
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37 # from OGC geom type name to Django field. |
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38 field_type = OGRGeomType(row[2]).django |
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39 |
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40 # Getting any GeometryField keyword arguments that are not the default. |
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41 dim = row[0] |
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42 srid = row[1] |
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43 field_params = {} |
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44 if srid != 4326: |
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45 field_params['srid'] = srid |
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46 if isinstance(dim, basestring) and 'Z' in dim: |
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47 field_params['dim'] = 3 |
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48 finally: |
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49 cursor.close() |
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50 |
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51 return field_type, field_params |