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https://github.com/rpkilby/jsonfield

A reusable Django model field for storing ad-hoc JSON data
https://github.com/rpkilby/jsonfield

django json python

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A reusable Django model field for storing ad-hoc JSON data

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README 

        
jsonfield

=========



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**jsonfield** is a reusable model field that allows you to store validated JSON, automatically handling

serialization to and from the database. To use, add ``jsonfield.JSONField`` to one of your models.



**Note:** `django.contrib.postgres`_ now supports PostgreSQL's jsonb type, which includes extended querying

capabilities. If you're an end user of PostgreSQL and want full-featured JSON support, then it is

recommended that you use the built-in JSONField. However, jsonfield is still useful when your app

needs to be database-agnostic, or when the built-in JSONField's extended querying is not being leveraged.

e.g., a configuration field.



.. _django.contrib.postgres: https://docs.djangoproject.com/en/dev/ref/contrib/postgres/fields/#jsonfield



Requirements

------------



**jsonfield** aims to support all current `versions of Django`_, however the explicity tested versions are:



* **Python:** 3.6, 3.7, 3.8

* **Django:** 2.2, 3.0



.. _versions of Django: https://www.djangoproject.com/download/#supported-versions



Installation

------------



.. code-block:: python



    pip install jsonfield



Usage

-----



.. code-block:: python



    from django.db import models

    from jsonfield import JSONField



    class MyModel(models.Model):

        json = JSONField()



Querying

--------



As stated above, ``JSONField`` is not intended to provide extended querying capabilities.

That said, you may perform the same basic lookups provided by regular text fields (e.g.,

``exact`` or ``regex`` lookups). Since values are stored as serialized JSON, it is highly

recommended that you test your queries to ensure the expected results are returned.



Handling null values

--------------------



A model field's ``null`` argument typically controls whether null values may be stored in

its column by setting a not-null constraint. However, because ``JSONField`` serializes its

values (including nulls), this option instead controls *how* null values are persisted. If

``null=True``, then nulls are **not** serialized and are stored as a null value in the

database. If ``null=False``, then the null is instead stored in its serialized form.



This in turn affects how null values may be queried. Both fields support exact matching:



.. code-block:: python



    MyModel.objects.filter(json=None)



However, if you want to use the ``isnull`` lookup, you must set ``null=True``.



.. code-block:: python



    class MyModel(models.Model):

        json = JSONField(null=True)



    MyModel.objects.filter(json__isnull=True)



Note that as ``JSONField.null`` does not prevent nulls from being stored, achieving this

must instead be handled with a validator.



Advanced Usage

--------------



By default python deserializes json into dict objects. This behavior differs from the standard json

behavior  because python dicts do not have ordered keys. To overcome this limitation and keep the

sort order of OrderedDict keys the deserialisation can be adjusted on model initialisation:



.. code-block:: python



    import collections



    class MyModel(models.Model):

        json = JSONField(load_kwargs={'object_pairs_hook': collections.OrderedDict})



Other Fields

------------



**jsonfield.JSONCharField**



Subclasses **models.CharField** instead of **models.TextField**.



Running the tests

-----------------



The test suite requires ``tox``.



.. code-block:: shell



    $ pip install tox



Then, run the ``tox`` command, which will run all test jobs.



.. code-block:: shell



    $ tox



Or, to test just one job (for example Django 2.0 on Python 3.6):



.. code-block:: shell



    $ tox -e py36-django20



Release Process

---------------



* Update changelog

* Update package version in setup.py

* Check supported versions in setup.py and readme

* Create git tag for version

* Upload release to PyPI test server

* Upload release to official PyPI server



.. code-block:: shell



    $ pip install -U pip setuptools wheel twine

    $ rm -rf dist/ build/

    $ python setup.py sdist bdist_wheel

    $ twine upload -r test dist/*

    $ twine upload dist/*



Changes

-------



Take a look at the `changelog`_.



.. _changelog: https://github.com/rpkilby/jsonfield/blob/master/CHANGES.rst