How to connect to multiple PostgreSQL schemas from Django?

Question

In my GeoDjango project I want to connect to a legacy PostgreSQL/PostGIS database. It contains the following schemas:

data // contains all the geospatial data
django // empty, created by me
public // system tables such as spatial_ref_sys

I want the Django tables shown in the screenshot to go into the django schema. I do not want to pollute the public schema.

I want the "data" models to connect to the data schema. I already tried to generate models from the legacy tables but python manage.py inspectdb connects to the public schema.

In order to provide access to the different schemas I adapted the approach 2 of this article which preassigns individual search_path values to specific database users:

-- user accessing django schema...
CREATE ROLE django_user LOGIN PASSWORD 'secret';
ALTER ROLE django_user SET search_path TO django, public;

-- user accessing data schema...
CREATE ROLE data_user LOGIN PASSWORD 'secret';
ALTER ROLE data_user SET search_path TO data, public;

Then I configured the database connections as follows:

DATABASES = {

    'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': 'multi_schema_db',
            'USER': 'django_user',
            'PASSWORD': 'secret',
    },

    'data': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': 'multi_schema_db',
            'USER': 'data_user',
            'PASSWORD': 'secret',
    },
}

How can I actually configure that Django uses the django schema while "data" models connect to the data schema?

Readings

See [Automatic database router](https://docs.djangoproject.com/en/1.8/topics/db/multi-db/#automatic-database-routing) — falsetru, Jul 30 '15 at 14:13
@falsetru The documentation for automatic database router does not mention how to deal with multiple schemas in the one database. — JJD, Aug 05 '15 at 17:07
@AbzRockers Only what you can read [here](http://stackoverflow.com/a/39322184/356895). — JJD, Jan 20 '17 at 11:06
@JJD Thank you for the response! I think you should mark it the right answer if it solved your problem, I neglected the answers on this question because it has no marked right answer and no up votes as well. — Abz Rockers, Jan 21 '17 at 07:04

score 11 · Answer 1 · answered Sep 04 '16 at 22:59

You have to leverage the search_path:

DATABASES = {

    'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'OPTIONS' : {
                'options': '-c search_path=django,public'
            },
            'NAME': 'multi_schema_db',
            'USER': 'django_user',
            'PASSWORD': 'secret',
    },

    'data': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'OPTIONS' : {
                'options': '-c search_path=data,public'
            },
            'NAME': 'multi_schema_db',
            'USER': 'data_user',
            'PASSWORD': 'secret',
    },
}

Source: Accessing multiple Postgres schemas from Django

score 7 · Answer 2 · edited Apr 09 '18 at 21:39

7

If you don't need to manage the tables through migrations, you could use escaped quotes for the db_table attribute of your model:

class SomeModel(models.Model):
    field1 = models.AutoField(primary_key=True)  
    class Meta():
        managed=False
        db_table=u'"schema\".\"table"'

edited Apr 09 '18 at 21:39

JJD

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answered Apr 03 '18 at 14:59

wbloos

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This worked for me. You can simply use without escaped quotes too. `db_table='schema"."table'` – Mathuv Jul 15 '19 at 04:45
This is great, and as far as I can tell, its working with migrations too! – ladorm Mar 31 '20 at 23:51
did not work for me nor with quotes neither without – Ladenkov Vladislav Apr 02 '20 at 09:43
**It worked for me** without `managed=False` and creating only the schema in the database before running any migrations. – sɪʒɪhɪŋ βɪstɦa kxɐll Apr 12 '22 at 06:23

Sina Khelil · Answer 3 · 2015-08-05T17:46:27.830

2

We use Django Tenant Schemas with great success. It allows you to access different schemas by delineating different tenants as the owners of the schemas.

This will allow you to set the schema on a per call basis. If the schema needs to be set on a per url basis, you can do that in middleware.

edited Aug 05 '15 at 17:46

answered Jul 30 '15 at 14:12

Sina Khelil

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How to connect to multiple PostgreSQL schemas from Django?

Readings

3 Answers3