Remove autogenerated 'id' when using existing database

[Ben in campus]

Django Version: (1, 8, 0, 'final', 0)

Issue: I have an existing database, so I integrated it following the instruction in https://docs.djangoproject.com/en/1.8/howto/legacy-databases/ to inspectdb and generated models.py. That table does NOT have column 'id', so the generated models.py doesn't have 'id' either. The model is unmanaged (managed = False).

But the Django page failed, saying something like 'can not find id column in the table'. Somehow the query added 'id' in the select fields.

Fixed: Modified /usr/local/lib/python2.7/dist-packages/django/db/models/options.py

Old: line 284-287

            else:

                auto = AutoField(verbose_name='ID', primary_key=True,

                            auto_created=True)

                model.add_to_class('id', auto)

New:

            else:

                if self.managed:

                    auto = AutoField(verbose_name='ID', primary_key=True,

                            auto_created=True)

                    model.add_to_class('id', auto)

That works well for my system. I think it makes sense that Django should not add AutoField for unmanaged class.

Please confirm and decide whether to patch this into your code base. Thanks.

Ben Lin
http://benincampus.blogspot.com

[Javier Guerra Giraldez]

On Tue, Apr 28, 2015 at 1:59 AM, Ben in campus <benin...@gmail.com> wrote:
> That table does NOT have column 'id', so the generated models.py doesn't
> have 'id' either. The model is unmanaged (managed = False).

if your table has a primary key, add the primary_key=True flag to that
field and Django won't add an 'id' field.

--
Javier

[Ben L]

It is true that the table doesn't have a primary key.

1, I might be able to talk to the DBA to add a primary key in here and re-sync the class. But is that required for each table to have pk to run Django?

2, what if I just modify the class to have fake pk =True, but not modify the database structure? Is that a common practice?

[Thorsten Sanders]

I do that since years with tables not having a primary key without
problems, but I am only using django orm on those to select data.