How to store a dictionary in a Django database model's field
I just discovered the django-jsonfield package, which
is a reusable Django field that allows you to store validated JSON in your model.
Looks like a viable option to achieve what you want.
One convenient way to store a JSON representation in a model is to use a custom field type:
class JSONField(models.TextField):
"""
JSONField is a generic textfield that neatly serializes/unserializes
JSON objects seamlessly.
Django snippet #1478
example:
class Page(models.Model):
data = JSONField(blank=True, null=True)
page = Page.objects.get(pk=5)
page.data = {'title': 'test', 'type': 3}
page.save()
"""
__metaclass__ = models.SubfieldBase
def to_python(self, value):
if value == "":
return None
try:
if isinstance(value, basestring):
return json.loads(value)
except ValueError:
pass
return value
def get_db_prep_save(self, value, *args, **kwargs):
if value == "":
return None
if isinstance(value, dict):
value = json.dumps(value, cls=DjangoJSONEncoder)
return super(JSONField, self).get_db_prep_save(value, *args, **kwargs)
I saved this utils/fields.py and in my model from utils.fields import JSONField
. There are many more goodies in the django-annoying app, which is where this snippet came from.
Using a custom field type is my preferred solution - I'd rather have a few lines of custom code than support an entire 3rd party library for a single field type. Tony Abou-Assaleh has a great solution, but won't work for newer versions of Django.
This is verified to work with Django 1.10.4
import json
from django.db import models
from django.core.serializers.json import DjangoJSONEncoder
class JSONField(models.TextField):
"""
JSONField is a generic textfield that neatly serializes/unserializes
JSON objects seamlessly.
Django snippet #1478
example:
class Page(models.Model):
data = JSONField(blank=True, null=True)
page = Page.objects.get(pk=5)
page.data = {'title': 'test', 'type': 3}
page.save()
"""
def to_python(self, value):
if value == "":
return None
try:
if isinstance(value, str):
return json.loads(value)
except ValueError:
pass
return value
def from_db_value(self, value, *args):
return self.to_python(value)
def get_db_prep_save(self, value, *args, **kwargs):
if value == "":
return None
if isinstance(value, dict):
value = json.dumps(value, cls=DjangoJSONEncoder)
return value