Custom delete method on queryset

问题

My Django model has custom logic in the delete method. Therefore since I wane to make sure that this logic is called when I call delete on my queryset, I wrote my own queryset delete.

class MyQuerySet(QuerySet):
    # Do we have to be any fancier here?
    def delete(self):
        for m in self:
            m.delete()

and my question is do I have to do anything fancier than iterating and calling delete on each instance?

回答1:

You should clear the result cache so if the queryset will be reused then DB query will be evaluated again.

Also you have to set two attributes:

• alters_data=True prevents calling this method from templates;

• queryset_only=True hides this method from queryset used as manager.

  class MyQuerySet(QuerySet):

  def delete(self):
      for m in self:
          m.delete()
      self._result_cache = None    
  delete.alters_data = True
  delete.queryset_only = True
  

来源：https://stackoverflow.com/questions/29127828/custom-delete-method-on-queryset