From 93cda768eed0f0c4ec9b53e5820ce94caaa463f9 Mon Sep 17 00:00:00 2001
From: Russell Keith-Magee <russell@keith-magee.com>
Date: Sun, 12 Sep 2010 20:05:17 +0000
Subject: [PATCH] Migrated expressions doctests. Thanks to Alex Gaynor.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@13790 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
tests/modeltests/expressions/models.py | 105 ------------
tests/modeltests/expressions/tests.py | 218 +++++++++++++++++++++++++
2 files changed, 218 insertions(+), 105 deletions(-)
create mode 100644 tests/modeltests/expressions/tests.py
diff --git a/tests/modeltests/expressions/models.py b/tests/modeltests/expressions/models.py
index f6292f5d9b..b004408536 100644
--- a/tests/modeltests/expressions/models.py
+++ b/tests/modeltests/expressions/models.py
@@ -25,108 +25,3 @@ class Company(models.Model):
def __unicode__(self):
return self.name
-
-
-__test__ = {'API_TESTS': """
->>> from django.db.models import F
-
->>> Company(name='Example Inc.', num_employees=2300, num_chairs=5,
-... ceo=Employee.objects.create(firstname='Joe', lastname='Smith')).save()
->>> Company(name='Foobar Ltd.', num_employees=3, num_chairs=3,
-... ceo=Employee.objects.create(firstname='Frank', lastname='Meyer')).save()
->>> Company(name='Test GmbH', num_employees=32, num_chairs=1,
-... ceo=Employee.objects.create(firstname='Max', lastname='Mustermann')).save()
-
->>> company_query = Company.objects.values('name','num_employees','num_chairs').order_by('name','num_employees','num_chairs')
-
-# We can filter for companies where the number of employees is greater than the
-# number of chairs.
->>> company_query.filter(num_employees__gt=F('num_chairs'))
-[{'num_chairs': 5, 'name': u'Example Inc.', 'num_employees': 2300}, {'num_chairs': 1, 'name': u'Test GmbH', 'num_employees': 32}]
-
-# We can set one field to have the value of another field
-# Make sure we have enough chairs
->>> _ = company_query.update(num_chairs=F('num_employees'))
->>> company_query
-[{'num_chairs': 2300, 'name': u'Example Inc.', 'num_employees': 2300}, {'num_chairs': 3, 'name': u'Foobar Ltd.', 'num_employees': 3}, {'num_chairs': 32, 'name': u'Test GmbH', 'num_employees': 32}]
-
-# We can perform arithmetic operations in expressions
-# Make sure we have 2 spare chairs
->>> _ =company_query.update(num_chairs=F('num_employees')+2)
->>> company_query
-[{'num_chairs': 2302, 'name': u'Example Inc.', 'num_employees': 2300}, {'num_chairs': 5, 'name': u'Foobar Ltd.', 'num_employees': 3}, {'num_chairs': 34, 'name': u'Test GmbH', 'num_employees': 32}]
-
-# Law of order of operations is followed
->>> _ =company_query.update(num_chairs=F('num_employees') + 2 * F('num_employees'))
->>> company_query
-[{'num_chairs': 6900, 'name': u'Example Inc.', 'num_employees': 2300}, {'num_chairs': 9, 'name': u'Foobar Ltd.', 'num_employees': 3}, {'num_chairs': 96, 'name': u'Test GmbH', 'num_employees': 32}]
-
-# Law of order of operations can be overridden by parentheses
->>> _ =company_query.update(num_chairs=((F('num_employees') + 2) * F('num_employees')))
->>> company_query
-[{'num_chairs': 5294600, 'name': u'Example Inc.', 'num_employees': 2300}, {'num_chairs': 15, 'name': u'Foobar Ltd.', 'num_employees': 3}, {'num_chairs': 1088, 'name': u'Test GmbH', 'num_employees': 32}]
-
-# The relation of a foreign key can become copied over to an other foreign key.
->>> Company.objects.update(point_of_contact=F('ceo'))
-3
-
->>> [c.point_of_contact for c in Company.objects.all()]
-[<Employee: Joe Smith>, <Employee: Frank Meyer>, <Employee: Max Mustermann>]
-
->>> c = Company.objects.all()[0]
->>> c.point_of_contact = Employee.objects.create(firstname="Guido", lastname="van Rossum")
->>> c.save()
-
-# F Expressions can also span joins
->>> Company.objects.filter(ceo__firstname=F('point_of_contact__firstname')).distinct().order_by('name')
-[<Company: Foobar Ltd.>, <Company: Test GmbH>]
-
->>> _ = Company.objects.exclude(ceo__firstname=F('point_of_contact__firstname')).update(name='foo')
->>> Company.objects.exclude(ceo__firstname=F('point_of_contact__firstname')).get().name
-u'foo'
-
->>> _ = Company.objects.exclude(ceo__firstname=F('point_of_contact__firstname')).update(name=F('point_of_contact__lastname'))
-Traceback (most recent call last):
-...
-FieldError: Joined field references are not permitted in this query
-
-# F expressions can be used to update attributes on single objects
->>> test_gmbh = Company.objects.get(name='Test GmbH')
->>> test_gmbh.num_employees
-32
->>> test_gmbh.num_employees = F('num_employees') + 4
->>> test_gmbh.save()
->>> test_gmbh = Company.objects.get(pk=test_gmbh.pk)
->>> test_gmbh.num_employees
-36
-
-# F expressions cannot be used to update attributes which are foreign keys, or
-# attributes which involve joins.
->>> test_gmbh.point_of_contact = None
->>> test_gmbh.save()
->>> test_gmbh.point_of_contact is None
-True
->>> test_gmbh.point_of_contact = F('ceo')
-Traceback (most recent call last):
-...
-ValueError: Cannot assign "<django.db.models.expressions.F object at ...>": "Company.point_of_contact" must be a "Employee" instance.
-
->>> test_gmbh.point_of_contact = test_gmbh.ceo
->>> test_gmbh.save()
->>> test_gmbh.name = F('ceo__last_name')
->>> test_gmbh.save()
-Traceback (most recent call last):
-...
-FieldError: Joined field references are not permitted in this query
-
-# F expressions cannot be used to update attributes on objects which do not yet
-# exist in the database
->>> acme = Company(name='The Acme Widget Co.', num_employees=12, num_chairs=5,
-... ceo=test_gmbh.ceo)
->>> acme.num_employees = F('num_employees') + 16
->>> acme.save()
-Traceback (most recent call last):
-...
-TypeError: ...
-
-"""}
diff --git a/tests/modeltests/expressions/tests.py b/tests/modeltests/expressions/tests.py
new file mode 100644
index 0000000000..0a136ae5d8
--- /dev/null
+++ b/tests/modeltests/expressions/tests.py
@@ -0,0 +1,218 @@
+from django.core.exceptions import FieldError
+from django.db.models import F
+from django.test import TestCase
+
+from models import Company, Employee
+
+
+class ExpressionsTests(TestCase):
+ def test_filter(self):
+ Company.objects.create(
+ name="Example Inc.", num_employees=2300, num_chairs=5,
+ ceo=Employee.objects.create(firstname="Joe", lastname="Smith")
+ )
+ Company.objects.create(
+ name="Foobar Ltd.", num_employees=3, num_chairs=4,
+ ceo=Employee.objects.create(firstname="Frank", lastname="Meyer")
+ )
+ Company.objects.create(
+ name="Test GmbH", num_employees=32, num_chairs=1,
+ ceo=Employee.objects.create(firstname="Max", lastname="Mustermann")
+ )
+
+ company_query = Company.objects.values(
+ "name", "num_employees", "num_chairs"
+ ).order_by(
+ "name", "num_employees", "num_chairs"
+ )
+
+ # We can filter for companies where the number of employees is greater
+ # than the number of chairs.
+ self.assertQuerysetEqual(
+ company_query.filter(num_employees__gt=F("num_chairs")), [
+ {
+ "num_chairs": 5,
+ "name": "Example Inc.",
+ "num_employees": 2300,
+ },
+ {
+ "num_chairs": 1,
+ "name": "Test GmbH",
+ "num_employees": 32
+ },
+ ],
+ lambda o: o
+ )
+
+ # We can set one field to have the value of another field
+ # Make sure we have enough chairs
+ company_query.update(num_chairs=F("num_employees"))
+ self.assertQuerysetEqual(
+ company_query, [
+ {
+ "num_chairs": 2300,
+ "name": "Example Inc.",
+ "num_employees": 2300
+ },
+ {
+ "num_chairs": 3,
+ "name": "Foobar Ltd.",
+ "num_employees": 3
+ },
+ {
+ "num_chairs": 32,
+ "name": "Test GmbH",
+ "num_employees": 32
+ }
+ ],
+ lambda o: o
+ )
+
+ # We can perform arithmetic operations in expressions
+ # Make sure we have 2 spare chairs
+ company_query.update(num_chairs=F("num_employees")+2)
+ self.assertQuerysetEqual(
+ company_query, [
+ {
+ 'num_chairs': 2302,
+ 'name': u'Example Inc.',
+ 'num_employees': 2300
+ },
+ {
+ 'num_chairs': 5,
+ 'name': u'Foobar Ltd.',
+ 'num_employees': 3
+ },
+ {
+ 'num_chairs': 34,
+ 'name': u'Test GmbH',
+ 'num_employees': 32
+ }
+ ],
+ lambda o: o,
+ )
+
+ # Law of order of operations is followed
+ company_query.update(
+ num_chairs=F('num_employees') + 2 * F('num_employees')
+ )
+ self.assertQuerysetEqual(
+ company_query, [
+ {
+ 'num_chairs': 6900,
+ 'name': u'Example Inc.',
+ 'num_employees': 2300
+ },
+ {
+ 'num_chairs': 9,
+ 'name': u'Foobar Ltd.',
+ 'num_employees': 3
+ },
+ {
+ 'num_chairs': 96,
+ 'name': u'Test GmbH',
+ 'num_employees': 32
+ }
+ ],
+ lambda o: o,
+ )
+
+ # Law of order of operations can be overridden by parentheses
+ company_query.update(
+ num_chairs=((F('num_employees') + 2) * F('num_employees'))
+ )
+ self.assertQuerysetEqual(
+ company_query, [
+ {
+ 'num_chairs': 5294600,
+ 'name': u'Example Inc.',
+ 'num_employees': 2300
+ },
+ {
+ 'num_chairs': 15,
+ 'name': u'Foobar Ltd.',
+ 'num_employees': 3
+ },
+ {
+ 'num_chairs': 1088,
+ 'name': u'Test GmbH',
+ 'num_employees': 32
+ }
+ ],
+ lambda o: o,
+ )
+
+ # The relation of a foreign key can become copied over to an other
+ # foreign key.
+ self.assertEqual(
+ Company.objects.update(point_of_contact=F('ceo')),
+ 3
+ )
+ self.assertQuerysetEqual(
+ Company.objects.all(), [
+ "Joe Smith",
+ "Frank Meyer",
+ "Max Mustermann",
+ ],
+ lambda c: unicode(c.point_of_contact),
+ )
+
+ c = Company.objects.all()[0]
+ c.point_of_contact = Employee.objects.create(firstname="Guido", lastname="van Rossum")
+ c.save()
+
+ # F Expressions can also span joins
+ self.assertQuerysetEqual(
+ Company.objects.filter(ceo__firstname=F("point_of_contact__firstname")), [
+ "Foobar Ltd.",
+ "Test GmbH",
+ ],
+ lambda c: c.name
+ )
+
+ Company.objects.exclude(
+ ceo__firstname=F("point_of_contact__firstname")
+ ).update(name="foo")
+ self.assertEqual(
+ Company.objects.exclude(
+ ceo__firstname=F('point_of_contact__firstname')
+ ).get().name,
+ "foo",
+ )
+
+ self.assertRaises(FieldError,
+ lambda: Company.objects.exclude(
+ ceo__firstname=F('point_of_contact__firstname')
+ ).update(name=F('point_of_contact__lastname'))
+ )
+
+ # F expressions can be used to update attributes on single objects
+ test_gmbh = Company.objects.get(name="Test GmbH")
+ self.assertEqual(test_gmbh.num_employees, 32)
+ test_gmbh.num_employees = F("num_employees") + 4
+ test_gmbh.save()
+ test_gmbh = Company.objects.get(pk=test_gmbh.pk)
+ self.assertEqual(test_gmbh.num_employees, 36)
+
+ # F expressions cannot be used to update attributes which are foreign
+ # keys, or attributes which involve joins.
+ test_gmbh.point_of_contact = None
+ test_gmbh.save()
+ self.assertTrue(test_gmbh.point_of_contact is None)
+ def test():
+ test_gmbh.point_of_contact = F("ceo")
+ self.assertRaises(ValueError, test)
+
+ test_gmbh.point_of_contact = test_gmbh.ceo
+ test_gmbh.save()
+ test_gmbh.name = F("ceo__last_name")
+ self.assertRaises(FieldError, test_gmbh.save)
+
+ # F expressions cannot be used to update attributes on objects which do
+ # not yet exist in the database
+ acme = Company(
+ name="The Acme Widget Co.", num_employees=12, num_chairs=5,
+ ceo=test_gmbh.ceo
+ )
+ acme.num_employees = F("num_employees") + 16
+ self.assertRaises(TypeError, acme.save)