Django remove bulk-delete

django, django-queryset, python

Solution

Like comments says on your first post, you have to create a subclass for each of these elements:

- The model manager

- Queryset class

- BaseModel

After some search, a great example can be found here, all credits to Akshay Shah, the blog author. Before looking to the code, be aware of that:

However, it inevitably leads to data corruption. The problem is simple: using a Boolean to store deletion status makes it impossible to enforce uniqueness constraints in your database.

from django.db import models
from django.db.models.query import QuerySet


class SoftDeletionQuerySet(QuerySet):
    def delete(self):
        # Bulk delete bypasses individual objects' delete methods.
        return super(SoftDeletionQuerySet, self).update(alive=False)

    def hard_delete(self):
        return super(SoftDeletionQuerySet, self).delete()

    def alive(self):
        return self.filter(alive=True)

    def dead(self):
        return self.exclude(alive=True)


class SoftDeletionManager(models.Manager):
    def __init__(self, *args, **kwargs):
        self.alive_only = kwargs.pop('alive_only', True)
        super(SoftDeletionManager, self).__init__(*args, **kwargs)

    def get_queryset(self):
        if self.alive_only:
            return SoftDeletionQuerySet(self.model).filter(alive=True)
        return SoftDeletionQuerySet(self.model)

    def hard_delete(self):
        return self.get_queryset().hard_delete()


class SoftDeletionModel(models.Model):
    alive = models.BooleanField(default=True)

    objects = SoftDeletionManager()
    all_objects = SoftDeletionManager(alive_only=False)

    class Meta:
        abstract = True

    def delete(self):
        self.alive = False
        self.save()

    def hard_delete(self):
        super(SoftDeletionModel, self).delete()

Basically, it adds an `alive` field to check if the row has been deleted or not, and update it when the `delete()` method is called. Of course, this method works only on project where you can manipulate the code base.

Problem

Original source