Getting old document before update

Is it possible to create a function that listens to an database document update event and retrieve it's old values?
Or do I need a workaround for that?

There was a feature request for something like this: https://github.com/appwrite/appwrite/issues/3294 You might want to 👍🏼 the issue.

One thing you can do is create a duplicate collection that contains the old document.

What exactly are you trying to do, though? What's your use case?

I need to verify if a change made by the user is valid. So yeah... I worked around the problem by creating a new doc with _old suffix...
Since the user has no create permission for the collection at all this is safe to use i guess.

Gave the issue a 👍

sounds like you're doing input validation? In that case, I would have the user make the update by executing a function instead of calling the database service directly. the function would do validation and reject the request if it's not valid.