Created some tests to show ORM queries that are problematic.

Still incomplete at the moment, but this version doesn't crash the test
framework.


git-svn-id: http://code.djangoproject.com/svn/django/branches/queryset-refactor@6113 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/queries/models.py

@@ -0,0 +1,192 @@
+"""
+Various combination queries that have been problematic in the past.
+"""
+
+from django.db import models
+from django.db.models.query import Q
+
+class Tag(models.Model):
+    name = models.CharField(maxlength=10)
+    parent = models.ForeignKey('self', blank=True, null=True)
+
+    def __unicode__(self):
+        return self.name
+
+class Author(models.Model):
+    name = models.CharField(maxlength=10)
+    num = models.IntegerField()
+
+    def __unicode__(self):
+        return self.name
+
+class Item(models.Model):
+    name = models.CharField(maxlength=10)
+    data_ = models.CharField(maxlength=10, blank=True, null=True)
+    tags = models.ManyToManyField(Tag, blank=True, null=True)
+    creator = models.ForeignKey(Author)
+
+    def __unicode__(self):
+        return self.name
+
+class Report(models.Model):
+    name = models.CharField(maxlength=10)
+    creator = models.ForeignKey(Author, to_field='num')
+
+    def __unicode__(self):
+        return self.name
+
+
+__test__ = {'API_TESTS':"""
+>>> t1 = Tag(name='t1')
+>>> t1.save()
+>>> t2 = Tag(name='t2', parent=t1)
+>>> t2.save()
+>>> t3 = Tag(name='t3', parent=t1)
+>>> t3.save()
+>>> t4 = Tag(name='t4', parent=t3)
+>>> t4.save()
+
+
+>>> a1 = Author(name='a1', num=1001)
+>>> a1.save()
+>>> a2 = Author(name='a2', num=2002)
+>>> a2.save()
+>>> a3 = Author(name='a3', num=3003)
+>>> a3.save()
+>>> a4 = Author(name='a4', num=4004)
+>>> a4.save()
+
+>>> i1 = Item(name='one', creator=a1)
+>>> i1.save()
+>>> i1.tags = [t1, t2]
+>>> i2 = Item(name='two', creator=a2)
+>>> i2.save()
+>>> i2.tags = [t1, t3]
+>>> i3 = Item(name='three', data_='x', creator=a2)
+>>> i3.save()
+>>> i4 = Item(name='four', creator=a4)
+>>> i4.save()
+>>> i4.tags = [t4]
+
+>>> r1 = Report(name='r1', creator=a1)
+>>> r1.save()
+
+Bug #1050
+>>> Item.objects.filter(tags__isnull=True)
+[<Item: three>]
+
+# FIXME: Crashes! :-(
+# >>> Item.objects.filter(tags__id__isnull=True)
+# [<Item: three>]
+
+Bug #1801
+>>> Author.objects.filter(item=i2)
+[<Author: a2>]
+>>> Author.objects.filter(item=i3)
+[<Author: a2>]
+
+# FIXME: When we join these queries, we MUST NOT share the table joins. this is
+# the case for all m-to-m and 1-to-m joins (but m-to-1 is fine).
+# >>> Author.objects.filter(item=i2) & Author.objects.filter(item=i3)
+# [<Author: a2>]
+
+Bug #2306
+Checking that no join types are "left outer" joins.
+>>> query = Item.objects.filter(tags=t2).query
+>>> query.LOUTER not in [x[2][2] for x in query.alias_map.values()]
+True
+
+>>> Item.objects.filter(Q(tags=t1)).order_by('name')
+[<Item: one>, <Item: two>]
+>>> Item.objects.filter(Q(tags=t1) & Q(tags=t2))
+[<Item: one>]
+>>> Item.objects.filter(Q(tags=t1)).filter(Q(tags=t2))
+[<Item: one>]
+
+Bug #4464
+>>> Item.objects.filter(tags=t1).filter(tags=t2)
+[<Item: one>]
+>>> Item.objects.filter(tags__in=[t1, t2]).distinct().order_by('name')
+[<Item: one>, <Item: two>]
+>>> Item.objects.filter(tags__in=[t1, t2]).filter(tags=t3)
+[<Item: two>]
+
+Bug #2080
+# FIXME: Still problematic: the join needs to be "left outer" on the reverse
+# fk, but the individual joins only need to be inner.
+# >>> Author.objects.filter(Q(name='a3') | Q(item__name='one'))
+# [<Author: a3>]
+
+Bug #2939
+# FIXME: ValueQuerySets don't work yet.
+# >>> Item.objects.values('creator').distinct().count()
+# 2
+
+Bug #2253
+>>> q1 = Item.objects.order_by('name')
+>>> q2 = Item.objects.filter(id=i1.id)
+>>> q1
+[<Item: four>, <Item: one>, <Item: three>, <Item: two>]
+>>> q2
+[<Item: one>]
+>>> (q1 | q2).order_by('name')
+[<Item: four>, <Item: one>, <Item: three>, <Item: two>]
+>>> (q1 & q2).order_by('name')
+[<Item: one>]
+
+Bug #3265
+# FIXME: Currently causes a crash. Probably not worth fixing, but must make it
+# a validation error in that case.
+# >>> Item.objects.get(data___exact='x')
+# <Item: three>
+
+Bugs #4088 & #4306
+>>> Report.objects.filter(creator=1001)
+[<Report: r1>]
+>>> Report.objects.filter(creator__num=1001)
+[<Report: r1>]
+
+# FIXME: The "removing final pk comparison" optimization is biting us here.
+# Need to only remove it if the join was also on the pk value.
+# >>> Report.objects.filter(creator__id=1001)
+# []
+# >>> Report.objects.filter(creator__id=a1.id)
+# [<Report: r1>]
+
+>>> Report.objects.filter(creator__name='a1')
+[<Report: r1>]
+
+Bug #4510
+>>> Author.objects.filter(report__name='r1')
+[<Author: a1>]
+
+Bug #5324
+>>> Item.objects.filter(tags__name='t4')
+[<Item: four>]
+
+# FIXME: We seem to be constructing the right SQL here, but maybe a NULL test
+# for the pk of Tag is needed or something?
+# >>> Item.objects.exclude(tags__name='t4').order_by('name').distinct()
+# [<Item: one>, <Item: three>, <Item: two>]
+
+Bug #2091
+>>> t = Tag.objects.get(name='t4')
+>>> Item.objects.filter(tags__in=[t])
+[<Item: four>]
+
+Combining querysets built on different models should behave in a well-defined
+fashion. We raise an error.
+>>> Author.objects.all() & Tag.objects.all()
+Traceback (most recent call last):
+...
+AssertionError: Cannot combine queries on two different base models.
+>>> Author.objects.all() | Tag.objects.all()
+Traceback (most recent call last):
+...
+AssertionError: Cannot combine queries on two different base models.
+
+Bug #3141
+>>> Author.objects.extra(select={'foo': '1'}).count()
+4
+"""}
+