[FIXED] dynamic check related relations in django

Issue

I have numerous models (OtherModels) associated with one main model (A). In the future, more models will be added. In my main model (A), which is connected to the others, I want to dynamically check whether any record from this main model (A) is related to other tables or not. What solution do you recommend?

class A(models.Model):
    name = models.CharField(_('Name'), max_length=255)

class OtherModels(models.Models):
    a = models.ForeignKey(A, on_deleted=models.PROTECT)

I use related_name and it's working, But since my relationships have become numerous, I can't use this method, and in the future, as it seems to me, it's not the right approach, especially considering they are expected to increase further.

Solution

I write a code to get related relations of a model and it works well for me, I have a MainModel that all of my models inherit of it and I wrote a method on it to access this method on all of my models:

    def has_relation(self, ignore_models=None) -> bool:
    """
    check if there is a relation from other models to this instance or not
    :param ignore_models: list of ignore models, should be model a.s. [Ticket, User]
    :return: True => there is a relation to this record
    """
    if ignore_models is None:
        ignore_models = []
    # ---
    try:
        for obj in self._meta.related_objects:
            field_name = obj.identity[0].name
            model = obj.identity[0].model
            lookup = {
                "is_deleted": False,
                field_name: self.id
            }
            if model in ignore_models:
                continue
            # ---
            relation_count = model.objects.filter(**lookup).count()
            if relation_count > 0:
                return True
        # ---
        return False
    except:
        return True

Answered By - javad mohammadi