Ticket #2080: m2o_or_lookup_test.2.diff

modeltests/many_to_one/models.py

@@ -217 +217 @@
 >>> Reporter.objects.filter(article__reporter__first_name__startswith='John').distinct()
 [<Reporter: John Smith>]
 
+
+# OR lookups across foreign keys
+#
+# At revision 3077, the last test cases fail to find a reporter with
+# no articles.  For someone not familiar with how the ORM works
+# internally, it's quite unexpected.
+#
+>>> from django.db.models import Q
+
+# Check that all is ok when all reporters queried do have articles:
+>>> Reporter.objects.filter(Q(first_name='John') |
+...                         Q(article__headline__startswith='Paul')).distinct()
+[<Reporter: John Smith>, <Reporter: Paul Jones>]
+>>> (Reporter.objects.filter(first_name='John') |
+...  Reporter.objects.filter(article__headline__startswith='Paul')).distinct()
+[<Reporter: John Smith>, <Reporter: Paul Jones>]
+
+# Create a new reporter Luke with no articles.
+>>> r3 = Reporter(first_name='Luke', last_name='Field', email='luke@example.com')
+>>> r3.save()
+
+# These queries fail to match the reporter with no articles:
+>>> Reporter.objects.filter(Q(first_name='Luke') |
+...                         Q(article__headline__startswith='Paul')).distinct()
+[<Reporter: Luke Field>, <Reporter: Paul Jones>]
+>>> (Reporter.objects.filter(first_name='Luke') |
+...  Reporter.objects.filter(article__headline__startswith='Paul')).distinct()
+[<Reporter: Luke Field>, <Reporter: Paul Jones>]
+
+# Maybe the problem is that an inner join is used instead of a left
+# outer join?
+>>> 'INNER JOIN' in (Reporter.objects.filter(first_name='Luke') |
+...                  Reporter.objects.filter(article__headline__startswith='Paul')).distinct()._get_sql_clause()[1]
+False
+
+# Clean up
+>>> r3.delete()
+
+
 # If you delete a reporter, his articles will be deleted.
 >>> Article.objects.all()
 [<Article: John's second story>, <Article: Paul's story>, <Article: This is a test>, <Article: This is a test>, <Article: This is a test>]