56 lines
2.2 KiB
Python
56 lines
2.2 KiB
Python
from django.contrib.gis.gdal import OGRGeomType
|
|
from django.db.backends.sqlite3.introspection import DatabaseIntrospection, FlexibleFieldLookupDict
|
|
from django.utils import six
|
|
|
|
|
|
class GeoFlexibleFieldLookupDict(FlexibleFieldLookupDict):
|
|
"""
|
|
Sublcass that includes updates the `base_data_types_reverse` dict
|
|
for geometry field types.
|
|
"""
|
|
base_data_types_reverse = FlexibleFieldLookupDict.base_data_types_reverse.copy()
|
|
base_data_types_reverse.update(
|
|
{'point': 'GeometryField',
|
|
'linestring': 'GeometryField',
|
|
'polygon': 'GeometryField',
|
|
'multipoint': 'GeometryField',
|
|
'multilinestring': 'GeometryField',
|
|
'multipolygon': 'GeometryField',
|
|
'geometrycollection': 'GeometryField',
|
|
})
|
|
|
|
|
|
class SpatiaLiteIntrospection(DatabaseIntrospection):
|
|
data_types_reverse = GeoFlexibleFieldLookupDict()
|
|
|
|
def get_geometry_type(self, table_name, geo_col):
|
|
cursor = self.connection.cursor()
|
|
try:
|
|
# Querying the `geometry_columns` table to get additional metadata.
|
|
type_col = 'type' if self.connection.ops.spatial_version < (4, 0, 0) else 'geometry_type'
|
|
cursor.execute('SELECT coord_dimension, srid, %s '
|
|
'FROM geometry_columns '
|
|
'WHERE f_table_name=%%s AND f_geometry_column=%%s' % type_col,
|
|
(table_name, geo_col))
|
|
row = cursor.fetchone()
|
|
if not row:
|
|
raise Exception('Could not find a geometry column for "%s"."%s"' %
|
|
(table_name, geo_col))
|
|
|
|
# OGRGeomType does not require GDAL and makes it easy to convert
|
|
# from OGC geom type name to Django field.
|
|
field_type = OGRGeomType(row[2]).django
|
|
|
|
# Getting any GeometryField keyword arguments that are not the default.
|
|
dim = row[0]
|
|
srid = row[1]
|
|
field_params = {}
|
|
if srid != 4326:
|
|
field_params['srid'] = srid
|
|
if isinstance(dim, six.string_types) and 'Z' in dim:
|
|
field_params['dim'] = 3
|
|
finally:
|
|
cursor.close()
|
|
|
|
return field_type, field_params
|