Sorting on number of reversed FK

[Dave-Lopper]

Hello!

I must be missing something basic, have been reading the docs for a long while, but I cannot find an answer to my question, it seems to be a basic use-case, which makes me think I most likely missed something:

I would like to sort a model (order_by) by the number of child relation, example:

class User(ormar.Model):
    class Meta:
        tablename = "users"
        metadata = metadata
        database = DB

    user_id: int = ormar.Integer(primary_key=True)
    customer: str = ormar.ForeignKey(Customer, name="customer_key")
    plan: str = ormar.ForeignKey(Plan, name="plan_id")

    first_name: Optional[str] = ormar.String(max_length=100, nullable=True)
    last_name: Optional[str] = ormar.String(max_length=100, nullable=True)
    ...

class Task(ormar.Model):
    class Meta:
        tablename = "tasks"
        metadata = metadata
        database = DB

    task_id: int = ormar.Integer(primary_key=True)
    user: int = ormar.ForeignKey(User, name="user_id", related_name="tasks")
    customer: str = ormar.ForeignKey(
        Customer, skip_reverse=True, name="customer_key"
    )

    rating: Optional[float] = ormar.Float(nullable=True)
    ...

I am having this kind of setup, and I would like to sort my users (before pagination) on their number of tasks,
I have tried several things but haven't got it working so far, what am I missing please?
Tried:

User.objects.select_related("tasks").order_by(len(User.tasks))
User.objects.select_related("tasks").order_by(User.tasks.count())
User.objects.select_related("tasks").order_by("tasks__count")
User.objects.select_related("tasks").order_by("tasks__len")

...

I also tried with a @property_field on my User class

@ormar.property_field
def task_count(self):
    return len(self.tasks)

But I didn't manage to sort on that property_field either

Please help :)

[Dave-Lopper]

Any update on this? I am sorry to follow-up, I have been digging the docs, trying what I would have done under SqlAlchemy, no success so far :/

[sorasful]

Same thing here, I did not find a solution. @Dave-Lopper , did you find a solution ?

[Dave-Lopper]

I have raised an issue regarding this and got an answer from the repo's creator: #566

Did it for me, might do it for you too :)