1 """

     2 9. Many-to-many relationships via an intermediary table

     3 

     4 For many-to-many relationships that need extra fields on the intermediary

     5 table, use an intermediary model.

     6 

     7 In this example, an ``Article`` can have multiple ``Reporter`` objects, and

     8 each ``Article``-``Reporter`` combination (a ``Writer``) has a ``position``

     9 field, which specifies the ``Reporter``'s position for the given article

    10 (e.g. "Staff writer").

    11 """

    12 

    13 from django.db import models

    14 

    15 class Reporter(models.Model):

    16     first_name = models.CharField(max_length=30)

    17     last_name = models.CharField(max_length=30)

    18 

    19     def __unicode__(self):

    20         return u"%s %s" % (self.first_name, self.last_name)

    21 

    22 class Article(models.Model):

    23     headline = models.CharField(max_length=100)

    24     pub_date = models.DateField()

    25 

    26     def __unicode__(self):

    27         return self.headline

    28 

    29 class Writer(models.Model):

    30     reporter = models.ForeignKey(Reporter)

    31     article = models.ForeignKey(Article)

    32     position = models.CharField(max_length=100)

    33 

    34     def __unicode__(self):

    35         return u'%s (%s)' % (self.reporter, self.position)

    36