Replacing delete, with hidden

One fairly common thing on a completed application is the request to hide rows from the database, rather than delete.

Just today I had this problem, and this was solved in just a couple of lines.

These are standard Django functions, nothing custom.

My current model (for example only)

class Category(models.Model):
    title = models.CharField(max_length=100, unique=True)

My new model

class Category(models.Model):
    title = models.CharField(max_length=100, unique=True)
    deleted = models.BooleanField(db_index=True)
    objects = NotDeleted()
    show_all = models.Manager()

What is this NotDeleted?, this is where the magic happens.

class NotDeleted(models.Manager):
    def get_query_set(self):
        return super(NotDeleted, self).get_query_set().filter(deleted=False)

This will automatically append deleted=False to your database query.

If for some reason you need to get deleted items again,

categories = Category.show_all.all()

You could create a separate manager, just to show deleted items as well.

For more information on Django database managers, http://docs.djangoproject.com/en/1.0/topics/db/managers/#modifying-initial-manager-querysets