PostGIS schema editor support (eece3c22) · Commits · Dom Sekotill / django

django/contrib/gis/db/backends/postgis/base.py

+5 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@ from django.db.backends.postgresql_psycopg2.base import DatabaseWrapper as Psyco
		from django.contrib.gis.db.backends.postgis.creation import PostGISCreation
		from django.contrib.gis.db.backends.postgis.introspection import PostGISIntrospection
		from django.contrib.gis.db.backends.postgis.operations import PostGISOperations
		from django.contrib.gis.db.backends.postgis.schema import PostGISSchemaEditor


		class DatabaseWrapper(Psycopg2DatabaseWrapper):
		@@ -12,3 +13,7 @@ class DatabaseWrapper(Psycopg2DatabaseWrapper):
		self.creation = PostGISCreation(self)
		self.ops = PostGISOperations(self)
		self.introspection = PostGISIntrospection(self)

		def schema_editor(self, args, *kwargs):
		"Returns a new instance of this backend's SchemaEditor"
		return PostGISSchemaEditor(self, args, *kwargs)

django/contrib/gis/db/backends/postgis/schema.py

0 → 100644

+87 −0

Original line number	Diff line number	Diff line
		from django.conf import settings
		from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
		from django.utils.functional import cached_property


		class PostGISSchemaEditor(DatabaseSchemaEditor):
		geom_index_type = 'GIST'
		geom_index_ops = 'GIST_GEOMETRY_OPS'
		geom_index_ops_nd = 'GIST_GEOMETRY_OPS_ND'

		sql_add_geometry_column = "SELECT AddGeometryColumn(%(table)s, %(column)s, %(srid)s, %(geom_type)s, %(dim)s)"
		sql_alter_geometry_column_not_null = "ALTER TABLE %(table)s ALTER COLUMN %(column)s SET NOT NULL"
		sql_add_spatial_index = "CREATE INDEX %(index)s ON %(table)s USING %(index_type)s (%(column)s %(ops)s)"

		def geo_quote_name(self, name):
		return self.connection.ops.geo_quote_name(name)

		def create_model(self, model):
		from django.contrib.gis.db.models.fields import GeometryField
		# Do model creation first
		super(PostGISSchemaEditor, self).create_model(model)
		# Now add any spatial field SQL
		sqls = []
		for field in model._meta.local_fields:
		if isinstance(field, GeometryField):
		sqls.extend(self.spatial_field_sql(model, field))
		for sql in sqls:
		self.execute(sql)

		def spatial_field_sql(self, model, field):
		"""
		Takes a GeometryField and returns a list of SQL to execute to
		create its spatial indexes.
		"""
		output = []

		if field.geography or self.connection.ops.geometry:
		# Geography and Geometry (PostGIS 2.0+) columns are
		# created normally.
		pass
		else:
		# Geometry columns are created by the `AddGeometryColumn`
		# stored procedure.
		output.append(
		self.sql_add_geometry_column % {
		"table": self.geo_quote_name(model._meta.db_table),
		"column": self.geo_quote_name(field.column),
		"srid": field.srid,
		"geom_type": self.geo_quote_name(field.geom_type),
		"dim": field.dim,
		}
		)
		if not field.null:
		output.append(
		self.sql_alter_geometry_column_not_null % {
		"table": self.quote_name(model._meta.db_table),
		"column": self.quote_name(field.column),
		},
		)

		if field.spatial_index:
		# Spatial indexes created the same way for both Geometry and
		# Geography columns.
		# PostGIS 2.0 does not support GIST_GEOMETRY_OPS. So, on 1.5
		# we use GIST_GEOMETRY_OPS, on 2.0 we use either "nd" ops
		# which are fast on multidimensional cases, or just plain
		# gist index for the 2d case.
		if field.geography:
		index_ops = ''
		elif self.connection.ops.geometry:
		if field.dim > 2:
		index_ops = self.geom_index_ops_nd
		else:
		index_ops = ''
		else:
		index_ops = self.geom_index_ops
		output.append(
		self.sql_add_spatial_index % {
		"index": self.quote_name('%s_%s_id' % (model._meta.db_table, field.column)),
		"table": self.quote_name(model._meta.db_table),
		"column": self.quote_name(field.column),
		"index_type": self.geom_index_type,
		"ops": index_ops,
		}
		)

		return output