I would like to combine two querysets, or better, make only one using the Case/When syntax for a specific case.
I have seen in the documentation that it can be use for queryset filtering, not only annotate, which is exactly what I need. However, I want to use the Case/When for the model field itself, not the value of the field.
The project is an e-commerce, I use django-oscar so the models are quite big to post them here. The thing to know is that a basket line refers to a product, and a product can either be parent, child or standalone.
Here is my code :
self.in_stock_lines = basket.lines.filter(product__product_class__track_stock=True, is_customized=False)
Thing is, if the basket line relates to a product being a child, the field I must filter on is product__parent__product_class__track_stock, whereas if it relates to a standalone product (having not parent), it stays product__product_class__track_stock as in my initial queryset.
Is there a way to do this ? Or do I have no choice but combine the two querysets using itertools.chain() for example ?
You can use Q objects for that.
from django.db.models import Q
basket.lines.filter(
Q(product_parent__isnull=True, product__product_class__track_stock=True) |
Q(product__parent__product_class__track_stock=True), is_customized=False)