from django.contrib.postgres.signals import (
get_citext_oids, get_hstore_oids, register_type_handlers,
)
from django.db.migrations.operations.base import Operation
[docs]class CreateExtension(Operation):
reversible = True
def __init__(self, name):
self.name = name
def state_forwards(self, app_label, state):
pass
def database_forwards(self, app_label, schema_editor, from_state, to_state):
if schema_editor.connection.vendor != 'postgresql':
return
schema_editor.execute("CREATE EXTENSION IF NOT EXISTS %s" % schema_editor.quote_name(self.name))
# Clear cached, stale oids.
get_hstore_oids.cache_clear()
get_citext_oids.cache_clear()
# Registering new type handlers cannot be done before the extension is
# installed, otherwise a subsequent data migration would use the same
# connection.
register_type_handlers(schema_editor.connection)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
schema_editor.execute("DROP EXTENSION %s" % schema_editor.quote_name(self.name))
# Clear cached, stale oids.
get_hstore_oids.cache_clear()
get_citext_oids.cache_clear()
def describe(self):
return "Creates extension %s" % self.name
May 01, 2019