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

posted @ 2012-10-30 14:23  zhu327  阅读(299)  评论(0)    收藏  举报