20121030 The django book 笔记 数据模型高级进阶

访问外键值

 1 >>> b = Book.objects.get(id=50)

 2 >>> b.publisher

 3 <Publisher: Apress Publishing>

 4 >>> b.publisher.website

 5 u'http://www.apress.com/'

 6 

 7 

 8 >>> p = Publisher.objects.get(name='Apress Publishing')

 9 >>> p.book_set.all()

10 [<Book: The Django Book>, <Book: Dive Into Python>, ...]

通过对象访问对应得外键,通过外键访问对应的外键的值p.book_set.all()

访问多对多值

1 >>> b = Book.objects.get(id=50)

2 >>> b.authors.all()

3 [<Author: Adrian Holovaty>, <Author: Jacob Kaplan-Moss>]

4 

5 

6 >>> a = Author.objects.get(first_name='Adrian', last_name='Holovaty')

7 >>> a.book_set.all()

8 [<Book: The Django Book>, <Book: Adrian's Other Book>]

正反查询

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