class Product(models.Model):
name = models.CharField()
group_id = models.CharField()
is_main = models.BooleanField()
def child(self):
return Product.objects.filter(group_id=self.group_id)products = Product.objects.filter(is_main=True){% for p in products %}
<ul>
{% for c in p.child %}
<li>{{ c.name }}</li>
{% endfor %}
</ul>
{% endfor %}products = Product.objects.filter(is_main=True)
groups = [item.group_id for item in products]
children = Product.objects.filter(group_id__in=groups).order_by('group_id')
children = {
grouper: elements for grouper, elements in
groupby(children, key=lambda x: x.group_id)
}
for product in products:
product.children = children.get(product.group_id, []){% for p in products %}
<ul>
{% for c in p.children %}
<li>{{ c.name }}</li>
{% endfor %}
</ul>
{% endfor %}main_products = Product.objects.filter(is_main=True)
all_products = Product.objects.filter(
Q(is_main=True) | Q(group_id__in=main_products.values_list("group_id", flat=True))
)str(Review.objects.filter(Q(user_id__gt=4000) | Q(user_id__in=Review.objects.values_list('user_id', flat=True))).query)
Out[10]: 'SELECT "reviews_review"."id", "reviews_review"."user_id", "reviews_review"."email", "reviews_review"."rating", "reviews_review"."comment", "reviews_review"."datetime" FROM "reviews_review" WHERE ("reviews_review"."user_id" > 4000 OR "reviews_review"."user_id" IN (SELECT U0."user_id" AS Col1 FROM "reviews_review" U0))'