Use select_related or just reference it in the template as an attribute.
https://docs.djangoproject.com/en/2.1/ref/models/querysets/#select-related
Product.objects.select_related(‘photo’)
{% if product.photo %}
…
{% endif %}
From: django-users@googlegroups.com [mailto:django-users@googlegroups.com] On
Behalf Of pythonwebdja...@gmail.com
Sent: Friday, April 26, 2019 8:03 AM
To: Django users
Subject: left join without where condition
What exactly I need?
I have 2 models Product and Photo(having ForeignKey relationship with
Product). Now suppose I inserted 3 products in Product table. For the 3rd
product I not inserted any photo in Photo table. I want to fetch all the
Products along with Photos but for the 3rd product photo should come as null(or
None) because I not inserted. why I am doing like this because for the product
for which no photos are uploaded I can check in the template that if null or
None is coming as a photo then show a default image referring it from the
static folder. I know we can achieve it using left join but how to achieve it
in Django style?
What I have tried?
q=Product.objects.all().filter(photo__isnull=True)
print(q.query)
SELECT "app_product"."id", "app_product"."name" FROM "app_product" LEFT OUTER
JOIN "app_photo" ON
("app_product"."id" = "app_photo"."product_id") WHERE "app_photo"."id" IS NOT
NULL
If in the above query I remove the where clause my problem will be resolved?
So how to do that in a django way?
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