# model
class User(AbstractUser):
pass
class Post(models.Model):
post = models.CharField(max_length=50)
user = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, blank=True)
# sql
SELECT A.username
,COUNT(B.*)
FROM users_user A
LEFT JOIN post B
ON B.user_id = A.id
GROUP BY A.id
users_user model is default django user model
I want to change query to orm
I tried both "post" and "post_set" using select_related, but I couldn't.
You can .annotate(…) [Django-doc] with:
from django.db.models import Count
User.objects.annotate(num_posts=Count('post'))The User objects that arise from this QuerySet will have an extra attribute .num_posts.
Note: It is normally better to make use of the
settings.AUTH_USER_MODEL[Django-doc] to refer to the user model, than to use theUsermodel [Django-doc] directly. For more information you can see the referencing theUsermodel section of the documentation.