id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
34440	AND operator on queryset with joins gives wrong results	Guillaume LEBRETON	David Sanders	"From the doc https://docs.djangoproject.com/en/4.1/ref/models/querysets/#operators-that-return-new-querysets, 2 queryset with a single filter argument merged by a ""&"" operator is equivalent to queryset with a filter with 2 arguments.


But with lookup with joins it do not seems to work that way:
 	

{{{
    # models.py
    ​
    class Person(models.Model):
        name = models.CharField(max_length=10, blank=True, null=True)
    ​
    ​
    class QuantitativeAttribute(models.Model):
        value = models.PositiveIntegerField()
        name = models.CharField(max_length=10)
        person = models.ForeignKey(Person,  on_delete=models.CASCADE)
    ​
    # tests.py
    ​
    class QuantitativeTestCase(TestCase):
    ​
        @classmethod
        def setUpTestData(cls):
    ​
            cls.p1 = Person.objects.create(name='p1')
            cls.p2 = Person.objects.create(name='p2')
    ​
            QuantitativeAttribute.objects.create(
                person=cls.p1,
                value=27,
                name='age',
            )
    ​
            QuantitativeAttribute.objects.create(
                person=cls.p1,
                value=55,
                name='concentration',
            )
    ​
            QuantitativeAttribute.objects.create(
                person=cls.p2,
                value=27,
                name='concentration',
            )
    ​
            QuantitativeAttribute.objects.create(
                person=cls.p2,
                value=55,
                name='age',
            )
    ​
        def test_combine_AND(self):
    ​
            expected_result = [
                {'name': 'p1'}
            ]
    ​
            with self.subTest('single filter qs'):
                qs = Person.objects.filter(quantitativeattribute__name='age', quantitativeattribute__value=27)
                self.assertQuerysetEqual(qs.values('name'), expected_result)
    ​
            with self.subTest('combined AND filter qs'):
                qs1 = Person.objects.filter(quantitativeattribute__name='age')
                qs2 = Person.objects.filter(quantitativeattribute__value=27)
                qs = qs1 & qs2
                self.assertQuerysetEqual(qs.values('name'), expected_result)

}}}

Here, the first subtest, `Person.objects.filter(quantitativeattribute__name='age', quantitativeattribute__value=27)` gives the desired result.

But the second subtest, `Person.objects.filter(quantitativeattribute__name='age') & Person.objects.filter(quantitativeattribute__value=27)` which according to the doc should be equal to the first subtest, is in fact equivalent to a chained filter query:
`Person.objects.filter(quantitativeattribute__name='age').filter(quantitativeattribute__value=27)`

As it is explained here https://docs.djangoproject.com/en/4.1/topics/db/queries/#spanning-multi-valued-relationships in the docs, chained filters is not the query that i want.

I tried to look for existing similar issue, i also went IRC #django but i did'nt find any answer yet. 
I think this ORM behavior is quite inconsistent, and at least it sould be stated in the doc for the ""&"" operator that the behavior may difer with joins"	Cleanup/optimization	closed	Documentation	4.1	Normal	fixed	orm and operato		Ready for checkin	1	0	0	0	0	0