Is it possible to increment a value with F in a json field in django?

Question

Is it possible to increment a value with F in a json field in django?

I have an object that contains a json field and I have some keys in it.

Is it possible to increment the key value inside a json used F?

Thank you for all.

credits = Company.objects.filter().first()
credits.meta_data = F('meta_data')['credits'] + 1
credits.save()

Answer 1

Not sure what F is, but given you meta_data is a valid JSON object, you can manipulate it with json library, for instance:

a = json.loads("{\"a\":1}")
#or a = json.loads(credits.meta_data)
print(a)
a["a"] = a["a"]+1
print(a)

{'a': 1}
{'a': 2}

You want to be careful (handle exceptions and ensure you save valid json content into this field), because even when you are using postgresql-specific json field, it does not guarantee that you are getting a properly formatted json objects from it.