Unable to import models which use uuid primary key

Describe the bug Importing models which use a uuid primary key (or any value that is generated in python, not the database) fails silently and the models do not import.

To Reproduce Steps to reproduce the behavior:

1. Create a model with a uuid primary key (id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False))
2. Create a custom ModelResource class to import and set use_bulk = True
3. Import a file containing NEW records
4. The import appears to be successful but the records are not imported

Versions (please complete the following information):

• Django Import Export: 2.5.0
• Python 3.9
• Django 3.2

Expected behavior The records should be imported.

Screenshots N/a

Additional context I believe it’s related to the following code in the save_instance method of the import_export.resources.Resource class:

          if self._meta.use_bulk:
            if instance.pk:
                self.update_instances.append(instance)
            else:
                self.create_instances.append(instance)

Since, when using a UUID, the pk is generated before the object is saved to the database, checking the value of pk against the instance is not a valid way to confirm whether the object exists or not.

A simple (if somewhat crude) fix would be, I believe:

          if self._meta.use_bulk:
            creating = (
                (hasattr(instance, "_state") and getattr(instance._state, "adding"))
                or instance.pk is None
            )
            if not creating:
                self.update_instances.append(instance)
            else:
                self.create_instances.append(instance)

[matthewhegarty]

Hi @matthewelwell, Yes I had to go back to the original approach due to the realisation that it wouldn’t actually fix your issue! This will be the final settled approach, but we’re likely delaying it to v3 (release date unknown) due to it breaking the API.

Obviously you’ll have to port it to your fork, or use the branch until v3 is released (which I doubt will be soon).

Thanks again for raising this and testing!

[matthewelwell]

Hey @matthewhegarty that sounds like a much better solution than the one I posted above.

I’ve temporarily forked the code and implemented my solution above to get things working. I will test this next week and let you know 👍