QuerySet - Q

Links

• Complex lookups with Q objects

Sample

from django.db import models

q = models.Q()
if user_to_forget.email:
    q |= models.Q(email__icontains=user_to_forget.email)
if user_to_forget.username:
    q |= models.Q(email__icontains=user_to_forget.username)
return self.model.objects.filter(q).order_by("email")

Note

q can be initialised using models.Q() or by using a filter: models.Q(pk__in=selection).

Using the Satchmo product database:

from django.db.models import Q

def _get_configurable_product_slugs(site):
    configurable_products = ConfigurableProduct.objects.filter(
        product__site=site)
    return [item.product.slug for item in configurable_products]

def _get_product_variation_slugs(site):
    product_variations = ProductVariation.objects.filter(
        product__site=site)
    return [item.product.slug for item in product_variations]

def products_with_standard_pricing(site):
    config_exclude = _get_configurable_product_slugs(site)
    variation_exclude = _get_product_variation_slugs(site)
    return Product.objects.filter(
        Q(site=site) &
        ~Q(slug__in=config_exclude) &
        ~Q(slug__in=variation_exclude)
        )

Note:

• In this sample, we are excluding configurable products and product variations.

• You can use the OR operator, | as well…