Question

i wanted to create a topic model.
this model would have a foreign key, non required, to the topic above it
for example:

iphone has a foreign key to apple

but what do i do if i want apple to be linked to all of its sub elements

apple to iPhone
apple to mac

i know that there are many to many fields, but how exactly would you apply them to this
situation

furthermore mac or iPhone might even have more sub elements

Answer 1

You probably want to look at the documentation for related_name. Basically Django does this for you. For example:

class Topic(models.Model):
    master_topic = models.ForeignKey('self',
                     null=True,
                     blank=True,
                     related_name="sub_topics")

Then access this code:

apple = Topic.objects.filter(tag='Apple')
sub_topics = apple.sub_topics.all() ## Gets all sub_topics.