django/tests/multiple_database/routers.py

61 lines
1.9 KiB
Python

from __future__ import unicode_literals
from django.db import DEFAULT_DB_ALIAS
class TestRouter(object):
# A test router. The behavior is vaguely primary/replica, but the
# databases aren't assumed to propagate changes.
def db_for_read(self, model, instance=None, **hints):
if instance:
return instance._state.db or 'other'
return 'other'
def db_for_write(self, model, **hints):
return DEFAULT_DB_ALIAS
def allow_relation(self, obj1, obj2, **hints):
return obj1._state.db in ('default', 'other') and obj2._state.db in ('default', 'other')
def allow_migrate(self, db, model):
return True
class AuthRouter(object):
"""A router to control all database operations on models in
the contrib.auth application"""
def db_for_read(self, model, **hints):
"Point all read operations on auth models to 'default'"
if model._meta.app_label == 'auth':
# We use default here to ensure we can tell the difference
# between a read request and a write request for Auth objects
return 'default'
return None
def db_for_write(self, model, **hints):
"Point all operations on auth models to 'other'"
if model._meta.app_label == 'auth':
return 'other'
return None
def allow_relation(self, obj1, obj2, **hints):
"Allow any relation if a model in Auth is involved"
if obj1._meta.app_label == 'auth' or obj2._meta.app_label == 'auth':
return True
return None
def allow_migrate(self, db, model):
"Make sure the auth app only appears on the 'other' db"
if db == 'other':
return model._meta.app_label == 'auth'
elif model._meta.app_label == 'auth':
return False
return None
class WriteRouter(object):
# A router that only expresses an opinion on writes
def db_for_write(self, model, **hints):
return 'writer'