Hey Bibhas, thank you for the report. I can verify that behavior and would classify it as a release blocker since it leads to potential data loss. Can you open a ticket on https://code.djangoproject.com/ please.
In general a migration is a collection of operations. The migration will only be unapplied if all operations are reversible. There is no direct way to prevent a migration (file) to be unapplied. I'm not sure if it's worth to add a property / attribute to the migration class to centralize that check. You could open a ticket as well. As a workaround you can add "migrations.RunPython(lambda apps, schema_editor: None)" as first operation in the operations list for that migration. It is a noop in forwards migrations and not reversible. But in adding a RunPython operation you will lose the ability to squash migrations. /Markus On Sunday, December 21, 2014 1:32:29 PM UTC+1, Bibhas wrote: > > Hi, > > I need to make a migration irreversible. And strangely I don't see any way > to do it in the migration doc. I see that the Operation class has a > property called `reversible`, but don't see any way to set it to False. > > I had a legacy model that was generated with inspectdb, hence it had > managed=False. But now when I Need to make changes to it I removed the > managed flag and the migration is trying to delete the table and create it > again. I removed the droptable operation and faked the migration to avoid > the error. But if I revert the migration, that table is going to be dropped > anyway, right? Because it's the revert operation of CreateTable. How do I > stop the backward migration for this particular migration? There is nothing > much important before it, so it's not a trouble if it's irreversible. > > Am I missing something really obvious? > > Thanks, > Bibhas > -- 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 [email protected]. To post to this group, send email to [email protected]. 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/6cbcca9e-d60d-419d-874c-e5d234e7c6a2%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
