deleting a device_type fails

[Paul Larson]

Looks like it's still referenced. I'm trying to simply change the name of snowball-sd to snowball_sd but when I tried to do that it created a new device_type instead. When trying to delete it, I get an error:

[Tue Oct 18 15:00:08 2011] [error] [client 75.27.138.6] IntegrityError: update or delete on table "lava_scheduler_app_devicetype" violates foreign key constraint "requested_device_type_id_refs_name_2f2696ac925e8aa7" on table "lava_scheduler_app_testjob", referer: http://validation.linaro.org/lava-server/admin/lava_scheduler_app/devicetype/
[Tue Oct 18 15:00:08 2011] [error] [client 75.27.138.6] DETAIL: Key (name)=(snowball-sd) is still referenced from table "lava_scheduler_app_testjob"., referer: http://validation.linaro.org/lava-server/admin/lava_scheduler_app/devicetype/

[Michael Hudson-Doyle (mwhudson)]

I noticed some wonkyness yesterday around the admin interface too (deleting devices fails too in similar ways).

Updating the name of a device type is going to be a bit tricky because it's the primary key of the table -- but I thought Django handled that.

You can always fix in with psql I guess :-)

[Michael Hudson-Doyle (mwhudson)]

OK, after a bit more poking I've come to the conclusion that we should not edit device_type ever.

Fortunately there's no real state in a device_type so we can add a type, move all references over to the new type and then delete the old one -- but do this using psql, not django.

[Zygmunt Krynicki (zyga)]

W dniu 19.10.2011 04:32, Michael Hudson-Doyle pisze:
> OK, after a bit more poking I've come to the conclusion that we should
> not edit device_type ever.
>
> Fortunately there's no real state in a device_type so we can add a type,
> move all references over to the new type and then delete the old one --
> but do this using psql, not django.

Django allows the same thing to happen, see on_delete in the model docs.

Thanks
ZK

[Michael Hudson-Doyle (mwhudson)]

On Wed, 19 Oct 2011 08:57:15 -0000, Zygmunt Krynicki <email address hidden> wrote:
> W dniu 19.10.2011 04:32, Michael Hudson-Doyle pisze:
> > OK, after a bit more poking I've come to the conclusion that we should
> > not edit device_type ever.
> >
> > Fortunately there's no real state in a device_type so we can add a type,
> > move all references over to the new type and then delete the old one --
> > but do this using psql, not django.
>
> Django allows the same thing to happen, see on_delete in the model docs.

Huh? Which same thing do you mean? The bit you're replying to is
talking about modifying primary keys, which is clearly a sketchy thing
to be doing but Django reacts to very strangely.

I'm aware of on_delete -- it's documented as defaulting to CASCADE
though, which clearly isn't happening here (even though I think it's a
bonkers default).