django1/django/contrib/postgres/signals.py

65 lines
2.2 KiB
Python

import functools
import psycopg2
from psycopg2 import ProgrammingError
from psycopg2.extras import register_hstore
from django.db import connections
from django.db.backends.base.base import NO_DB_ALIAS
@functools.lru_cache()
def get_hstore_oids(connection_alias):
"""Return hstore and hstore array OIDs."""
with connections[connection_alias].cursor() as cursor:
cursor.execute(
"SELECT t.oid, typarray "
"FROM pg_type t "
"JOIN pg_namespace ns ON typnamespace = ns.oid "
"WHERE typname = 'hstore'"
)
oids = []
array_oids = []
for row in cursor:
oids.append(row[0])
array_oids.append(row[1])
return tuple(oids), tuple(array_oids)
@functools.lru_cache()
def get_citext_oids(connection_alias):
"""Return citext array OIDs."""
with connections[connection_alias].cursor() as cursor:
cursor.execute("SELECT typarray FROM pg_type WHERE typname = 'citext'")
return tuple(row[0] for row in cursor)
def register_type_handlers(connection, **kwargs):
if connection.vendor != 'postgresql' or connection.alias == NO_DB_ALIAS:
return
try:
oids, array_oids = get_hstore_oids(connection.alias)
register_hstore(connection.connection, globally=True, oid=oids, array_oid=array_oids)
except ProgrammingError:
# Hstore is not available on the database.
#
# If someone tries to create an hstore field it will error there.
# This is necessary as someone may be using PSQL without extensions
# installed but be using other features of contrib.postgres.
#
# This is also needed in order to create the connection in order to
# install the hstore extension.
pass
try:
citext_oids = get_citext_oids(connection.alias)
array_type = psycopg2.extensions.new_array_type(citext_oids, 'citext[]', psycopg2.STRING)
psycopg2.extensions.register_type(array_type, None)
except ProgrammingError:
# citext is not available on the database.
#
# The same comments in the except block of the above call to
# register_hstore() also apply here.
pass