Bob,
You can control the order in which migrations run.
For South, see "depends_on" and "needed_by":
- http://south.readthedocs.org/en/latest/dependencies.html
For Django 1.7 migrations, see "dependencies":
- https://docs.djangoproject.com/en/dev/topics/migrations/#dependencies
--Fred
------------------------------------------------------------------------
Fred Stluka -- mailto:f...@bristle.com -- http://bristle.com/~fred/
Bristle Software, Inc -- http://bristle.com -- Glad to be of service!
Open Source: Without walls and fences, we need no Windows or Gates.
------------------------------------------------------------------------
On 9/26/14 9:58 AM, bobhaugen wrote:
Andrew, thanks for the article, and the more-to-come.
When you get to data migrations, you might want to cover a problem I
ran into with them: when I had a data migration in the middle of a
sequence of other migrations, and then later wanted to set up a new
environment, which meant running all of the migrations in sequence
from the beginning, the data migration was now running in the latest
models.py code, not the code in which it initially worked. So it did
not work any more.
In particular, the data migration was a precursor to another schema
migration were a field would be removed. The data migration was to
move the existing data in the field-to-be-removed to a different
field. So when the data migration ran in the longer sequence, the
field it was trying to move data from was now gone from the code.
I suspect there are a lot of other ways to shoot yourself in the foot
with data migrations, so we have stopped using them and just use our
own data migration scripts outside of the sequence of schema migrations.
--
You received this message because you are subscribed to the Google
Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to django-users+unsubscr...@googlegroups.com
<mailto:django-users+unsubscr...@googlegroups.com>.
To post to this group, send email to django-users@googlegroups.com
<mailto:django-users@googlegroups.com>.
Visit this group at http://groups.google.com/group/django-users.
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-users/9f4e1b6a-4051-478d-9a09-43318266ed7f%40googlegroups.com
<https://groups.google.com/d/msgid/django-users/9f4e1b6a-4051-478d-9a09-43318266ed7f%40googlegroups.com?utm_medium=email&utm_source=footer>.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "Django
users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to django-users+unsubscr...@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-users/54258067.1080405%40bristle.com.
For more options, visit https://groups.google.com/d/optout.
