Django 1.9 Jsonfield Order_by

I have the following django model that contains JSONField: class RatebookDataEntry(models.Model): data = JSONField(blank=True, default=[]) last_update = models.DateTimeFiel

Solution 1:

As Julien mentioned ordering on JSONField is not yet supported in Django. But it's possible via RawSQL using PostgreSQL functions for jsonb. In OP's case:

from django.db.models.expressions import RawSQL
RatebookDataEntry.objects.all().order_by(RawSQL("data->>%s", ("manufacturer_name",)))

Solution 2:

Since Django 1.11, django.contrib.postgres.fields.jsonb.KeyTextTransform can be used instead of RawSQL

from django.contrib.postgres.fields.jsonb import KeyTextTransform

qs = RatebookEntry.objects.all()
qs = qs.annotate(manufacturer_name=KeyTextTransform('manufacturer_name', 'data'))
qs = qs.order_by('manufacturer_name')
# or...
qs = qs.order_by('-manufacturer_name')

On Django 1.10, you'll have to subclass KeyTransform yourself:

from django.contrib.postgres.fields.jsonb import KeyTransform

classKeyTextTransform(KeyTransform):
    operator = '->>'
    nested_operator = '#>>'
    _output_field = TextField()

Note: the difference between KeyTransform and KeyTextTransform is that KeyTransform will return the JSON representation of the object, whereas KeyTextTransform will return the value of the object.

For example, if data is {"test": "stuff"}, KeyTextTransform will return 'stuff', whereas KeyTransform will return '"stuff"' (which can be parsed by json.loads)

Solution 3:

Following Daniil Ryzhkov answer and Eugene Prikazchikov comment, you should be able to sort ASC and DESC on JSON data fields without annotating your queryset, by using both RawSQL and OrderBy. Also, you can perform case insensitive sorting by adding LOWER:

from django.db.models.expressions import RawSQL, OrderBy

RatebookDataEntry.objects.all().order_by(OrderBy(RawSQL("LOWER(data->>%s)", ("manufacturer_name",)), descending=True))

To compare integers fields, you can cast as integer:

RatebookDataEntry.objects.all().order_by(OrderBy(RawSQL("cast(data->>%s as integer)", ("annual_mileage",)), descending=True))

Solution 4:

This is an upcoming feature which has already been added and will be released in Django 2.1, expected release of August 2018.

See https://code.djangoproject.com/ticket/24747 and https://github.com/django/django/pull/8528 for details.

Solution 5:

This question (and most of the answers) are for Django 1.9. However, Django versions 3.1 and newer support JSONFieldon recent versions of MariaDB, MySQL, Oracle, PostgreSQL, and SQLite.

The behavior around creating/maintaining indexes on JSON fields may vary across database engines, but ordering should work with the exact syntax you have in your question:

RatebookDataEntry.objects.all().order_by("data__manufacturer_name")

Note that unless you do further filtering, this will include database rows where the manufacturer_name key in the data JSONField does not exist.