Simplified DatabaseIntrospection.get_geometry_type() for PostGIS.

This commit is contained in:
Nick Pope 2019-01-19 15:09:44 +00:00 committed by Tim Graham
parent e19f58fc01
commit d82f212ec8
1 changed files with 10 additions and 25 deletions

View File

@ -2,10 +2,6 @@ from django.contrib.gis.gdal import OGRGeomType
from django.db.backends.postgresql.introspection import DatabaseIntrospection from django.db.backends.postgresql.introspection import DatabaseIntrospection
class GeoIntrospectionError(Exception):
pass
class PostGISIntrospection(DatabaseIntrospection): class PostGISIntrospection(DatabaseIntrospection):
# Reverse dictionary for PostGIS geometry types not populated until # Reverse dictionary for PostGIS geometry types not populated until
# introspection is actually performed. # introspection is actually performed.
@ -65,33 +61,22 @@ class PostGISIntrospection(DatabaseIntrospection):
metadata tables to determine the geometry type. metadata tables to determine the geometry type.
""" """
with self.connection.cursor() as cursor: with self.connection.cursor() as cursor:
try: cursor.execute("""
# First seeing if this geometry column is in the `geometry_columns` SELECT t.coord_dimension, t.srid, t.type FROM (
cursor.execute('SELECT "coord_dimension", "srid", "type" ' SELECT * FROM geometry_columns
'FROM "geometry_columns" ' UNION ALL
'WHERE "f_table_name"=%s AND "f_geometry_column"=%s', SELECT * FROM geography_columns
(table_name, geo_col)) ) AS t WHERE t.f_table_name = %s AND t.f_geometry_column = %s
""", (table_name, geo_col))
row = cursor.fetchone() row = cursor.fetchone()
if not row:
raise GeoIntrospectionError
except GeoIntrospectionError:
cursor.execute('SELECT "coord_dimension", "srid", "type" '
'FROM "geography_columns" '
'WHERE "f_table_name"=%s AND "f_geography_column"=%s',
(table_name, geo_col))
row = cursor.fetchone()
if not row: if not row:
raise Exception('Could not find a geometry or geography column for "%s"."%s"' % raise Exception('Could not find a geometry or geography column for "%s"."%s"' %
(table_name, geo_col)) (table_name, geo_col))
dim, srid, field_type = row
# OGRGeomType does not require GDAL and makes it easy to convert # OGRGeomType does not require GDAL and makes it easy to convert
# from OGC geom type name to Django field. # from OGC geom type name to Django field.
field_type = OGRGeomType(row[2]).django field_type = OGRGeomType(field_type).django
# Getting any GeometryField keyword arguments that are not the default. # Getting any GeometryField keyword arguments that are not the default.
dim = row[0]
srid = row[1]
field_params = {} field_params = {}
if srid != 4326: if srid != 4326:
field_params['srid'] = srid field_params['srid'] = srid