[1.2.X] Migrated expressions doctests. Thanks to Alex Gaynor. (67522582) · Commits · Dom Sekotill / django

tests/modeltests/expressions/models.py

+0 −105

Original line number	Diff line number	Diff line
		@@ -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: ...

		"""}

tests/modeltests/expressions/tests.py

0 → 100644

+218 −0

Original line number	Diff line number	Diff line
		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)