django_libsql

libSQL backend compatibility for django.

Pre-requisites

You must have a running instance of sqld, which is the libSQL server mode. There are several supported options:

Build and run an instance on your local machine.
Use an instance managed by Turso.
Use the libSQL test server implemented in python

Co-requisites

This custom backend requires django version 4.1.0 or higher and libsql_client

Getting started

In your django project settings, if you're using the sqlite engine you'll find something like this

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

Just change the engine name to django_libsql and your database name to the appropriate Turso URL

DATABASES = {
    'default': {
        'ENGINE': 'django_libsql',
        'NAME': 'libsql://you-database-hostname?authToken=your-auth-token'
    }
}

Or, if you're running a local instance of sqld, the name will be just libsql://127.0.0.1:PORT.

Known issues

The implementation of the standard sqlite backend for django uses the create_function api in order to define some custom functionalities of the framework. We currently do not support this feature in the libsql_client, which means we don't support the functions listed here.

You can see which functions are registered to a given database by querying the pragma_function_list table. When running django with the standard sqlite backend, the functions mentioned above will be registered, whereas with django_libsql, they won't.

More concretely, here are some of the things that will not work in the current version:

Let the model Product be defined by:

    class Product(models.Model):
        made_at = models.DateTimeField()
        valid_until = models.DateTimeField()

Then

    >>> from django.db.models import F
    >>> Product.objects.annotate(date_diff=F("valid_until") - F("made_at"))

will raise: django.db.utils.OperationalError: SQL_INPUT_ERROR: SQL input error: no such function: django_timestamp_diff (at offset 87)

Let the model ShcoolClass be defined by:

    class SchoolClass(models.Model):
        year = models.PositiveIntegerField()
        day = models.CharField(max_length=9, blank=True)
        last_updated = models.DateTimeField()

        objects = SchoolClassManager()

Then

    >>> import datetime
    >>> updated = datetime.datetime(2023, 2, 20)
    >>> SchoolClass.objects.create(year=2022, last_updated=updated)
    <SchoolClass: SchoolClass object (3)>
    >>> years = SchoolClass.objects.dates("last_updated", "year")
    >>> years

will raise: django.db.utils.OperationalError: SQL_INPUT_ERROR: SQL input error: no such function: django_date_trunc (at offset 16)

These are some examples, but in general, any framework feature that uses the functions listed here will not work for the time being.

License