Django how to use separate database for default authentication - django

Question

I have a database created from non-django app and have defined the database connection info like below
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('POSTGRES_DB'),
'USER': os.environ.get('POSTGRES_USER'),
'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
'HOST': os.environ.get('POSTGRES_HOST'),
'PORT': os.environ.get('POSTGRES_PORT'),
}
}
Unfortunately, when I migrate the django admin related tables, they all go into the default database.
I know that it is possible to declare multiple databases and separate read and write actions to different databases; however, what I would like to do is to have all the default django admin related tables to be created into another database. Say I declare a second database like below, how do I make sure that django admin related datas get migrated to the second database and also read from that when I login to django admin?
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('POSTGRES_DB'),
'USER': os.environ.get('POSTGRES_USER'),
'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
'HOST': os.environ.get('POSTGRES_HOST'),
'PORT': os.environ.get('POSTGRES_PORT'),
},
'admin':{
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('ADMIN_POSTGRES_DB'),
'USER': os.environ.get('ADMIN_POSTGRES_USER'),
'PASSWORD': os.environ.get('ADMIN_POSTGRES_PASSWORD'),
'HOST': os.environ.get('ADMIN_POSTGRES_HOST'),
'PORT': os.environ.get('ADMIN_POSTGRES_PORT'),
}
}

Answer 1

first you must leave default dictionary as empty
then define your database for admin and non admin
for examample do this
DATABASES = {
'default':{},
'nonAdmin': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('POSTGRES_DB'),
'USER': os.environ.get('POSTGRES_USER'),
'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
'HOST': os.environ.get('POSTGRES_HOST'),
'PORT': os.environ.get('POSTGRES_PORT'),
},
'admin':{
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('ADMIN_POSTGRES_DB'),
'USER': os.environ.get('ADMIN_POSTGRES_USER'),
'PASSWORD': os.environ.get('ADMIN_POSTGRES_PASSWORD'),
'HOST': os.environ.get('ADMIN_POSTGRES_HOST'),
'PORT': os.environ.get('ADMIN_POSTGRES_PORT'),
}
}
then after that you can migrate database using
./manage.py migrate --database=admin
or
./manage.py migrate --database=nonAdmin
If you don’t want every application to be synchronized onto a particular database, you can define a database router that implements a policy constraining the availability of particular models.
by using this method
allow_migrate(db, app_label, model_name=None, **hints)
you can reference this document https://docs.djangoproject.com/en/3.0/topics/db/multi-db/#topics-db-multi-db-routing