3 files changed, 114 insertions, 0 deletions
diff --git a/parts/django/tests/modeltests/m2m_multiple/__init__.py b/parts/django/tests/modeltests/m2m_multiple/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/parts/django/tests/modeltests/m2m_multiple/__init__.py
diff --git a/parts/django/tests/modeltests/m2m_multiple/models.py b/parts/django/tests/modeltests/m2m_multiple/models.py
new file mode 100644
index 0000000..e53f840
--- /dev/null
+++ b/parts/django/tests/modeltests/m2m_multiple/models.py
@@ -0,0 +1,30 @@
+"""
+20. Multiple many-to-many relationships between the same two tables
+
+In this example, an ``Article`` can have many "primary" ``Category`` objects
+and many "secondary" ``Category`` objects.
+
+Set ``related_name`` to designate what the reverse relationship is called.
+"""
+
+from django.db import models
+
+class Category(models.Model):
+    name = models.CharField(max_length=20)
+    class Meta:
+       ordering = ('name',)
+
+    def __unicode__(self):
+        return self.name
+
+class Article(models.Model):
+    headline = models.CharField(max_length=50)
+    pub_date = models.DateTimeField()
+    primary_categories = models.ManyToManyField(Category, related_name='primary_article_set')
+    secondary_categories = models.ManyToManyField(Category, related_name='secondary_article_set')
+    class Meta:
+       ordering = ('pub_date',)
+
+    def __unicode__(self):
+        return self.headline
+
diff --git a/parts/django/tests/modeltests/m2m_multiple/tests.py b/parts/django/tests/modeltests/m2m_multiple/tests.py
new file mode 100644
index 0000000..1f4503a
--- /dev/null
+++ b/parts/django/tests/modeltests/m2m_multiple/tests.py
@@ -0,0 +1,84 @@
+from datetime import datetime
+
+from django.test import TestCase
+
+from models import Article, Category
+
+
+class M2MMultipleTests(TestCase):
+    def test_multiple(self):
+        c1, c2, c3, c4 = [
+            Category.objects.create(name=name)
+            for name in ["Sports", "News", "Crime", "Life"]
+        ]
+
+        a1 = Article.objects.create(
+            headline="Area man steals", pub_date=datetime(2005, 11, 27)
+        )
+        a1.primary_categories.add(c2, c3)
+        a1.secondary_categories.add(c4)
+
+        a2 = Article.objects.create(
+            headline="Area man runs", pub_date=datetime(2005, 11, 28)
+        )
+        a2.primary_categories.add(c1, c2)
+        a2.secondary_categories.add(c4)
+
+        self.assertQuerysetEqual(
+            a1.primary_categories.all(), [
+                "Crime",
+                "News",
+            ],
+            lambda c: c.name
+        )
+        self.assertQuerysetEqual(
+            a2.primary_categories.all(), [
+                "News",
+                "Sports",
+            ],
+            lambda c: c.name
+        )
+        self.assertQuerysetEqual(
+            a1.secondary_categories.all(), [
+                "Life",
+            ],
+            lambda c: c.name
+        )
+        self.assertQuerysetEqual(
+            c1.primary_article_set.all(), [
+                "Area man runs",
+            ],
+            lambda a: a.headline
+        )
+        self.assertQuerysetEqual(
+            c1.secondary_article_set.all(), []
+        )
+        self.assertQuerysetEqual(
+            c2.primary_article_set.all(), [
+                "Area man steals",
+                "Area man runs",
+            ],
+            lambda a: a.headline
+        )
+        self.assertQuerysetEqual(
+            c2.secondary_article_set.all(), []
+        )
+        self.assertQuerysetEqual(
+            c3.primary_article_set.all(), [
+                "Area man steals",
+            ],
+            lambda a: a.headline
+        )
+        self.assertQuerysetEqual(
+            c3.secondary_article_set.all(), []
+        )
+        self.assertQuerysetEqual(
+            c4.primary_article_set.all(), []
+        )
+        self.assertQuerysetEqual(
+            c4.secondary_article_set.all(), [
+                "Area man steals",
+                "Area man runs",
+            ],
+            lambda a: a.headline
+        )