Some strange problem in Model inheritance and selected_related

[davydov.ilya@…]

Hi.
I've found some strange problem.
I have 2 models.

class Product(models.Model):

id = models.AutoField(primary_key=True)
price = models.IntegerField(db_column='price', default=0)

class Meta:

db_table = 'product'

class CurrentProduct(Product):

parent_product = models.OneToOneField(Product, parent_link=True, related_name='current_product', db_column='parent')
price_test = models.IntegerField(default=0, db_column='price_frame')

class Meta:

db_table = 'door'

Product.objects.selected_related('current_product').all()

The above query return all products. But price_test in subobjects current_product will be casted to:
1) if price_test >= 2 - long
2) if price_test == 1 or price_test == 0 - bool !!!!!!!!!!

It's very strange.

It doesn't repeat if selected_related isn't specified!

What do you mean about it?

[Tim Graham]

I wrote a test for Django's test suite based on your description, but I can't reproduce the problem. Can you provide more details and/or tell me if my test isn't correct for the problem you're seeing?

[Anssi Kääriäinen]

The value conversion has changed a lot in recent versions. In addition value conversion is DB backend specific.

To triage this ticket we need information of used Django version and which backend is in use.

[anonymous]

Hi.
I've written small apllication that reproduce this situation. I've attached it to ticket.
I use: DB Mysql and Django 1.6.1

Please, look at next screenshots:
​http://gyazo.com/782dbfc4fb34a362021cba5ca0095448
​http://gyazo.com/e2f475a6547a29389a2b250113a31b7c

If you need more information, could you contact me by email: davydov.ilya@…?

[anonymous]

Why did you close this bug?

[anonymous]

I've used
MySQL-python==1.2.5
Django 1.6.1

[Anssi Kääriäinen]

Hmmh... maybe this too will be fixed by 9918c11114ac3ec9622631558ef26ebf3919cb69 (see tickets #21903, #21413). I can't verify that right now. Trying that ​https://github.com/akaariai/django/commit/e9a48efe366f1fab7e888cd9648ba69a06bece4a fixes the issue would be very helpful.

[anonymous]

You've fixed this problem in release 1.6.2! Thank you!