未在模型中创建Django ManyToMany字段

Question

Here is my Model for Teacher class.

class Teacher(Profile):
    class Meta:
        db_table = 'teacher'

    user = models.OneToOneField(User,
                                unique=True,
                                verbose_name=_('user'),
                                related_name='teacher')

    home_address =  models.CharField(_('home_address'), max_length=255, blank=True)
    home_phone =  models.CharField(_('home_phone'), max_length=30, blank=True)
    cell_phone =  models.CharField(_('cell_phone'), max_length=30, blank=True)
    experience =  models.IntegerField(default = 0)
    summary =  models.TextField(_('summary'), max_length=500, blank=True)
    subjects = models.ManyToManyField(Subjects, through='SubjectsIntermediate')

When i execute the manage.py syncdb it does creates the teacher table with all fields except for field subjects . Why the subjects field is not created??

Answer 1

Because a ManyToMany isn't a field, at least not one that exists as a database column. It's a relationship with a linking table. You'll find that a table named myapp_teacher_subjects has been created, with foreign keys to both teacher and subjects.