Fix: No longer throw an error with relationship fields by using the a…

…ctual column instead of the name.

src/modelsubquery/functions.py

@@ -13,7 +13,7 @@ def _model_fields(model, fields):
     then return all the declared fields.
     """
     # TODO: the pk/id field should always be returned
-    declared = {f.name for f in model._meta.get_fields()}
+    declared = {f.column for f in model._meta.get_fields()}
     if fields is None:
         return declared
 

testproject/testapp/models.py

@@ -2,7 +2,6 @@
 
 from django.db import models
 from django.db.models.functions import ExtractYear
-
 from modelsubquery import ModelSubquery
 
 
@@ -11,6 +10,9 @@ class Book(models.Model):
     rating = models.IntegerField(blank=True, null=True)
     published = models.DateField(default=date.today)
     has_cover = models.BooleanField(default=True)
+    author = models.ForeignKey(
+        "Person", on_delete=models.CASCADE, related_name="books", null=True
+    )
 
 
 class PersonQuerySet(models.QuerySet):

testproject/testapp/tests.py

@@ -79,3 +79,16 @@ def test_deffered_fields(self):
             self.assertEqual(person.book_of_year.title, "test")
         with self.assertNumQueries(1):
             self.assertEqual(person.book_of_year.rating, 5)
+
+    def test_with_related_field(self):
+        author = baker.make(Person)
+        book = baker.make(Book, author=author)
+
+        # Yes he wrote a book in his birthyear! ;-)
+
+        person = Person.objects.with_book_of_the_year().get()
+        self.assertEqual(person.book_of_year, book)
+
+        # The relation is there, but it's lazy!
+        with self.assertNumQueries(1):
+            self.assertEqual(person.book_of_year.author, author)