/tests/modeltests/m2m_and_m2o/tests.py

from django.db.models import Q
from django.test import TestCase

from models import Issue, User


class RelatedObjectTests(TestCase):
    def test_m2m_and_m2o(self):
        r = User.objects.create(username="russell")
        g = User.objects.create(username="gustav")

        i1 = Issue(num=1)
        i1.client = r
        i1.save()

        i2 = Issue(num=2)
        i2.client = r
        i2.save()
        i2.cc.add(r)

        i3 = Issue(num=3)
        i3.client = g
        i3.save()
        i3.cc.add(r)

        self.assertQuerysetEqual(
            Issue.objects.filter(client=r.id), [
                1,
                2,
            ],
            lambda i: i.num
        )
        self.assertQuerysetEqual(
            Issue.objects.filter(client=g.id), [
                3,
            ],
            lambda i: i.num
        )
        self.assertQuerysetEqual(
            Issue.objects.filter(cc__id__exact=g.id), []
        )
        self.assertQuerysetEqual(
            Issue.objects.filter(cc__id__exact=r.id), [
                2,
                3,
            ],
            lambda i: i.num
        )

        # These queries combine results from the m2m and the m2o relationships.
        # They're three ways of saying the same thing.
        self.assertQuerysetEqual(
            Issue.objects.filter(Q(cc__id__exact = r.id) | Q(client=r.id)), [
                1,
                2,
                3,
            ],
            lambda i: i.num
        )
        self.assertQuerysetEqual(
            Issue.objects.filter(cc__id__exact=r.id) | Issue.objects.filter(client=r.id), [
                1,
                2,
                3,
            ],
            lambda i: i.num
        )
        self.assertQuerysetEqual(
            Issue.objects.filter(Q(client=r.id) | Q(cc__id__exact=r.id)), [
                1,
                2,
                3,
            ],
            lambda i: i.num
        )