1 """

     2 33. get_or_create()

     3 

     4 get_or_create() does what it says: it tries to look up an object with the given

     5 parameters. If an object isn't found, it creates one with the given parameters.

     6 """

     7 

     8 from django.db import models

     9 

    10 class Person(models.Model):

    11     first_name = models.CharField(maxlength=100)

    12     last_name = models.CharField(maxlength=100)

    13     birthday = models.DateField()

    14 

    15     def __str__(self):

    16         return '%s %s' % (self.first_name, self.last_name)

    17 

    18 __test__ = {'API_TESTS':"""

    19 # Acting as a divine being, create an Person.

    20 >>> from datetime import date

    21 >>> p = Person(first_name='John', last_name='Lennon', birthday=date(1940, 10, 9))

    22 >>> p.save()

    23 

    24 # Only one Person is in the database at this point.

    25 >>> Person.objects.count()

    26 1

    27 

    28 # get_or_create() a person with similar first names.

    29 >>> p, created = Person.objects.get_or_create(first_name='John', last_name='Lennon', defaults={'birthday': date(1940, 10, 9)})

    30 

    31 # get_or_create() didn't have to create an object.

    32 >>> created

    33 False

    34 

    35 # There's still only one Person in the database.

    36 >>> Person.objects.count()

    37 1

    38 

    39 # get_or_create() a Person with a different name.

    40 >>> p, created = Person.objects.get_or_create(first_name='George', last_name='Harrison', defaults={'birthday': date(1943, 2, 25)})

    41 >>> created

    42 True

    43 >>> Person.objects.count()

    44 2

    45 

    46 # If we execute the exact same statement, it won't create a Person.

    47 >>> p, created = Person.objects.get_or_create(first_name='George', last_name='Harrison', defaults={'birthday': date(1943, 2, 25)})

    48 >>> created

    49 False

    50 >>> Person.objects.count()

    51 2

    52 """}