92 lines
1.9 KiB
Python
92 lines
1.9 KiB
Python
from django.db import models
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class Publisher(models.Model):
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name = models.CharField(max_length=100)
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class Author(models.Model):
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name = models.CharField(max_length=100)
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class Book(models.Model):
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name = models.CharField(max_length=100)
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authors = models.ManyToManyField(Author, related_name='books')
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publisher = models.ForeignKey(Publisher, related_name='books')
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__test__ = {'one':"""
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#
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# RelatedManager
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#
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# First create a Publisher.
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>>> p = Publisher.objects.create(name='Acme Publishing')
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# Create a book through the publisher.
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>>> book, created = p.books.get_or_create(name='The Book of Ed & Fred')
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>>> created
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True
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# The publisher should have one book.
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>>> p.books.count()
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1
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# Try get_or_create again, this time nothing should be created.
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>>> book, created = p.books.get_or_create(name='The Book of Ed & Fred')
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>>> created
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False
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# And the publisher should still have one book.
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>>> p.books.count()
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1
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#
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# ManyRelatedManager
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#
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# Add an author to the book.
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>>> ed, created = book.authors.get_or_create(name='Ed')
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>>> created
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True
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# Book should have one author.
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>>> book.authors.count()
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1
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# Try get_or_create again, this time nothing should be created.
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>>> ed, created = book.authors.get_or_create(name='Ed')
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>>> created
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False
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# And the book should still have one author.
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>>> book.authors.count()
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1
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# Add a second author to the book.
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>>> fred, created = book.authors.get_or_create(name='Fred')
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>>> created
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True
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# The book should have two authors now.
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>>> book.authors.count()
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2
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# Create an Author not tied to any books.
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>>> Author.objects.create(name='Ted')
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<Author: Author object>
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# There should be three Authors in total. The book object should have two.
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>>> Author.objects.count()
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3
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>>> book.authors.count()
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2
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# Try creating a book through an author.
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>>> ed.books.get_or_create(name="Ed's Recipies", publisher=p)
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(<Book: Book object>, True)
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# Now Ed has two Books, Fred just one.
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>>> ed.books.count()
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2
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>>> fred.books.count()
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1
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"""}
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