set() doesn't do anything

Using Django Using the ORM
1

Hello peeps, I have an issue which is driving me against the wall. I have a an ORM setup where I create a VirtualMachine model and then create a ManyToMany relationship with django users

    owners = models.ManyToManyField(User,blank=True, db_index=True)

Later I have a method where I might need to change the owners of the VM. To do this, I use set() like so

    existing_owners = list(existing_vm.owners.order_by("username").all())
    for owner_uuid in vm_json.get('members',[]):
        owner = find_or_create_user(owner_uuid)
        if owner is not None:
            owners.append(owner)
    if existing_owners != owners:
        logger.info(f"VM {existing_vm.name} owners list differ from the DB. Updating DB with new owners.")
        existing_vm.owners.set(owners, clear=True)

This all runs without an errors but…doesn’t change the relationship. Adding logging before and after the operation, I can clearly see that the owners var is different, but after the set() the DB still reports the old relationships. I made sure that this is not any caching issue by restarting the app and subsequent operations confirm the owners never changed.

Given that there’s no errors whatsoever, I’m struggling to understand how I can troubleshoot this.

Any advise is appreciated.

2

It would help out if you gave more context/code to see where it might be going wrong.

3

Nevermind, I just realized the list of owners was including a duplicate user, so when assigning the set(), django was of course ignoring the duplicate, but I was counting the absolute number of entries in the list and seeing a disparity. In short, my bad. Adding a list(set()) first to deduplicate it ,fixed it.