Is this how django does Single Table Inheritance?

Question

In this SO question I see the following:

class MediaContent(models.Model):
    uploader = models.ForeignKey(User)
    title = models.CharField(max_length=100)
    created = models.DateTimeField(auto_now_add=True)

    def draw_item(self):
        pass

    class Meta:
        abstract = True

class Picture(MediaContent):
    picture = models.ImageField(upload_to='pictures')

class Video(MediaContent):
    identifier = models.CharField(max_length=30) #youtube id

I have done some STI in Rails before, but never in django. Is this how it's done in django? Will it only create one table having all the fields in all the models? Will it add a type column?

The acronym 'STI' isn't widely used in the Django world (and appears to be largely a Rails-ism). It would have been clearer if you'd spelt it out in full in your question title. — Andy Baker, Jun 09 '11 at 08:51
Sorry, I spelled it out full in the tag. I thought it would be enough. I will edit the title. — Geo, Jun 09 '11 at 09:28

score 4 · Answer 1 · edited May 23 '17 at 12:24

4

Unfortunately, Django does not support single table inheritance: Single Table Inheritance in Django

edited May 23 '17 at 12:24

Community

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answered Jun 12 '11 at 09:41

Juande Carrion

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score 3 · Accepted Answer · answered Jun 09 '11 at 07:32

3

There will be two tables created, one for Picture, and one for Video. It will not be possible to create a query that returns both types.

"Abstract base classes"

answered Jun 09 '11 at 07:32

Ignacio Vazquez-Abrams

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And both tables will also have the fields defined in MediaContent? – Geo Jun 09 '11 at 07:38
Plus the fields defined in the specific class, yes. – Ignacio Vazquez-Abrams Jun 09 '11 at 07:39
Also see: http://code.google.com/p/django-polymorphic-models/ and similar for ways to query across model inheritance chains. – Andy Baker Jun 09 '11 at 08:52
@andybak: Is that supposed to be able to work with abstract superclasses? – Ignacio Vazquez-Abrams Jun 09 '11 at 08:54

Is this how django does Single Table Inheritance?

2 Answers2