Django-1.2.1/tests/modeltests/get_or_create/models.py

   1 """
   2 33. get_or_create()
   3
   4 ``get_or_create()`` does what it says: it tries to look up an object with the
   5 given parameters. If an object isn't found, it creates one with the given
   6 parameters.
   7 """
   8
   9 from django.db import models, IntegrityError
  10
  11 class Person(models.Model):
  12     first_name = models.CharField(max_length=100)
  13     last_name = models.CharField(max_length=100)
  14     birthday = models.DateField()
  15
  16     def __unicode__(self):
  17         return u'%s %s' % (self.first_name, self.last_name)
  18
  19 class ManualPrimaryKeyTest(models.Model):
  20     id = models.IntegerField(primary_key=True)
  21     data = models.CharField(max_length=100)
  22
  23 __test__ = {'API_TESTS':"""
  24 # Acting as a divine being, create an Person.
  25 >>> from datetime import date
  26 >>> p = Person(first_name='John', last_name='Lennon', birthday=date(1940, 10, 9))
  27 >>> p.save()
  28
  29 # Only one Person is in the database at this point.
  30 >>> Person.objects.count()
  31 1
  32
  33 # get_or_create() a person with similar first names.
  34 >>> p, created = Person.objects.get_or_create(first_name='John', last_name='Lennon', defaults={'birthday': date(1940, 10, 9)})
  35
  36 # get_or_create() didn't have to create an object.
  37 >>> created
  38 False
  39
  40 # There's still only one Person in the database.
  41 >>> Person.objects.count()
  42 1
  43
  44 # get_or_create() a Person with a different name.
  45 >>> p, created = Person.objects.get_or_create(first_name='George', last_name='Harrison', defaults={'birthday': date(1943, 2, 25)})
  46 >>> created
  47 True
  48 >>> Person.objects.count()
  49 2
  50
  51 # If we execute the exact same statement, it won't create a Person.
  52 >>> p, created = Person.objects.get_or_create(first_name='George', last_name='Harrison', defaults={'birthday': date(1943, 2, 25)})
  53 >>> created
  54 False
  55 >>> Person.objects.count()
  56 2
  57
  58 # If you don't specify a value or default value for all required fields, you
  59 # will get an error.
  60 >>> try:
  61 ...     p, created = Person.objects.get_or_create(first_name='Tom', last_name='Smith')
  62 ... except Exception, e:
  63 ...     if isinstance(e, IntegrityError):
  64 ...         print "Pass"
  65 ...     else:
  66 ...         print "Fail with %s" % type(e)
  67 Pass
  68
  69 # If you specify an existing primary key, but different other fields, then you
  70 # will get an error and data will not be updated.
  71 >>> m = ManualPrimaryKeyTest(id=1, data='Original')
  72 >>> m.save()
  73 >>> try:
  74 ...    m, created = ManualPrimaryKeyTest.objects.get_or_create(id=1, data='Different')
  75 ... except Exception, e:
  76 ...    if isinstance(e, IntegrityError):
  77 ...        print "Pass"
  78 ...    else:
  79 ...        print "Fail with %s" % type(e)
  80 Pass
  81 >>> ManualPrimaryKeyTest.objects.get(id=1).data == 'Original'
  82 True
  83 """}