I'm using peewee as ORM for a project and want to extend it to handle logical deletes.
I've added "deleted" field to my base model and have extended the delete operations as follows:
@classmethod
def delete(cls, permanently=False):
if permanently:
return super(BaseModel, cls).delete()
else:
return super(BaseModel, cls).update(deleted=True, modified_at=datetime.datetime.now())
def delete_instance(self, permanently=False, recursive=False, delete_nullable=False):
if permanently:
return self.delete(permanently).where(self.pk_expr()).execute()
else:
self.deleted = True
return self.save()
This works great. However, when I'm overriding select I get some problems.
@classmethod
def select(cls, *selection):
print selection
return super(BaseModel, cls).select(cls, *selection).where(cls.deleted == False)
This works in most cases, but in certains selects it breaks when the resulting query ends up using a join with the keyword "IN" with the following error: "1241, 'Operand should contain 1 column(s)"
Any suggestion on how to properly override select or work around this problem?
I always use a field on my models to indicate whether the model is deleted. I do not recommend overriding methods like delete, delete_instance and especially select. Rather create a new API and use that. Here's how I typically do it:
class StatusModel(Model):
status = IntegerField(
choices=(
(1, 'Public'),
(2, 'Private'),
(3, 'Deleted')),
default=1)
@classmethod
def public(cls):
return cls.select().where(cls.status == 1)