Question

How does Django decide what in the model will be assigned an _id, when generated automatically on ‘syncdb’? (from this tut https://docs.djangoproject.com/en/1.1/intro/tutorial01/)

Secondly, when I run a ‘p.save()’, how does Django assign the id=i number?

Answer 1

From the exact page you linked:

By convention, Django appends “_id” to the foreign key field name.

(In other words, _id gets suffixed to any models.ForeignKey() fields.)

Every model in Django has an id field that is specific to that model (which is what p.id is, there). This is used when referencing a given item from that model. It’s called a “primary key”. It’s typically set via simply looking at what the highest current primary key is for that model, and then adding 1.

For instance, the very first instance of a model you create will probably have id=1. The second would then have id=2, and so on.