Add support for CompositePrimaryKey in QuerySet.raw()

[Adam Johnson]

Currently, a check in RawModelIterable fails for models with a CompositePrimaryKey.

For example, this model:

class AuthorEvent(models.Model):
    timestamp = models.DateTimeField(auto_now_add=True)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)
    pk = models.CompositePrimaryKey(
        "author",
        "timestamp",
    )

fails like:

In [2]: list(AuthorEvent.objects.raw("SELECT * FROM example_authorevent"))
---------------------------------------------------------------------------
FieldDoesNotExist                         Traceback (most recent call last)
Cell In[2], line 1
----> 1 list(AuthorEvent.objects.raw("SELECT * FROM example_authorevent"))

File ..../django/db/models/query.py:2133, in RawQuerySet.__iter__(self)
   2132 def __iter__(self):
-> 2133     self._fetch_all()
   2134     return iter(self._result_cache)

File ..../django/db/models/query.py:2120, in RawQuerySet._fetch_all(self)
   2118 def _fetch_all(self):
   2119     if self._result_cache is None:
-> 2120         self._result_cache = list(self.iterator())
   2121     if self._prefetch_related_lookups and not self._prefetch_done:
   2122         self._prefetch_related_objects()

File ..../django/db/models/query.py:2147, in RawQuerySet.iterator(self)
   2146 def iterator(self):
-> 2147     yield from RawModelIterable(self)

File ..../django/db/models/query.py:169, in RawModelIterable.__iter__(self)
    167 model_cls = self.queryset.model
    168 if model_cls._meta.pk.attname not in model_init_names:
--> 169     raise exceptions.FieldDoesNotExist(
    170         "Raw query must include the primary key"
    171     )
    172 fields = [self.queryset.model_fields.get(c) for c in self.queryset.columns]
    173 cols = [f.get_col(f.model._meta.db_table) if f else None for f in fields]

FieldDoesNotExist: Raw query must include the primary key

To add support, we should add a test, update this check to look for all columns in the PK, and fix anything else as necessary.

[Sarah Boyce]

Thank you for the report!
I've marked this as a new feature to add support but I can be persuaded to have this as a release blocking bug

Replicated:

tests/composite_pk/tests.py

@@ -158 +158 @@
         users = User.objects.values_list("pk").order_by("pk")
         self.assertNotIn('AS "pk"', str(users.query))
 
+    def test_raw(self):
+        users = User.objects.raw("SELECT * FROM composite_pk_user")
+        self.assertEqual(len(users), 1)
+
     def test_only(self):
         users = User.objects.only("pk")
         self.assertSequenceEqual(users, (self.user,))

[Csirmaz Bendegúz]

thanks for the cc! I see, we have overlooked raw queries. I wasn't aware of this check there

agreed it's not release blocking, but it does feel like a bug

it should be an easy fix, marking it as "easy pickings" in case a newcomer wants to pick it up

[Adam Johnson]

Yeah, I wouldn't make this a release blocker, just another "extra support" feature ticket :)

[Sarah Boyce <42296566+sarahboyce@…>]

In 1831f77:

Fixed #36326 -- Added CompositePrimaryKey support in QuerySet.raw().

Signed-off-by: SaJH <wogur981208@…>