Append to models.JSONField on POST

[chris jess]

Can anyone let me know the best way to append to a models.JSONField on HTTP POST?

I would prefer to simply append to the existing JSONField as opposed to updating the values in it.

Is it possible to do this without first loading that object?

Thanks.

[ludovic coues]

You can't.

There is 7 value types in JSON.
3 of them are constant, true, false and null. Appending to them make no sense.
You could append to number, but then you change its value.
String are double quote delimited. You can't append to it, you need to
insert before the closing double quote. aka updating.
Any way, I'm pretty sure JSONField don't let you use these values as
root object for some reason.

The two remaining value types are array and object. Both suffer from
the same issue as string, they are delimited and you can't simply
append at the end, you need to insert data, aka updating.


If you know what you are doing, read the source, look at how to update
the raw value, write some test to make sure what you are doing is
working now and is working each time you upgrade django.

I wish you good luck if you go down that path and to have a good experience.

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Cordialement, Coues Ludovic
+336 148 743 42

[chris jess]

Thanks. 

Was hoping there was a method for appending to a JSON array stored in a JSONField without fetching the whole record first.

[ludovic coues]

If there is one, I've never heard of it. But I'm not an heavy user of
postgres or its JSONField.
Maybe someone else know better than me :)

> https://groups.google.com/d/msgid/django-users/f39ffbe6-e1e2-457f-9298-932ee2574306%40googlegroups.com.