prefetch related post

bad-template-loop.html

<ul>
    {% for product in products %}
    <li>
        <h4>{{ product.name }}</h4>

        <ul>
            {% for feature in product.feature_set.all %}
            <li>{{ feature.name }}</li>
            {% endfor %}
        </ul>
    </li>
    {% endfor %}
</ul>

prefetch-queryset.py

Product.objects.all().prefetch_related('feature_set')

prefetch.sql

SELECT
    "products_feature"."id",
    "products_feature"."product_id",
    "products_feature"."name"
FROM
    "products_feature"
WHERE
    "products_feature"."product_id" IN (1, 2, 3, 4, 5)

print-sql-example.py

print Product.objects.all().query

product-sql-example.sql

SELECT
    "products_product"."id",
    "products_product"."name",
    "products_product"."description"
FROM
    "products_product"