On Thu, 25 May 2017 18:00:34 +1000 Brian May <bam@debian.org> wrote: > Thorsten Glaser <t.glaser@tarent.de> writes: > > > How, by the way, is the upgrade from jessie to stretch handled? > > If this makes users lose data (without using the 1.8 packages) > > that’s probably an RC bug. > > Django is just a Python library. Django itself has no data or > configuration. Upgrading/Downgrading it will not affect data in > anyway. No, sorry. Changes in the code have a direct effect on the user data, it is unavoidable. Django is an Object Relational Model. It directly controls user data in the database. Upgrading django changes the way that the model is mapped to the data with new models, new fields and deprecation of old models and fields. When the django code changes, there must be database migrations created which run ALTER TABLE SQL calls during the installation of the package using django. If a feature is deprecated in one LTS and removed in the next, then the developer release after that will simply fail to handle the migration which runs the ALTER TABLE. This is what happens with 1.7 to 1.10. The migration process fails because 1.8 changed the way that dependencies are handled within the migration process. > It is the applications that use Django that may have to handle data > migrations. An version of an application that supports a newer version > of Django will typically be a newer version that could have database > changes. Except when django itself changes the way it calculates how to process those migrations, as happened with 1.8. > This is typically handled with Django DB migrations. There should not > be any problems migrating from one upstream version to new version > (if they have done their job correctly), the migrations keep track of > what needs to happen automatically. > Having an intermediate step between Jessie and Stretch does not change > this in anyway. You will still end up running exactly the same > migrations by the time you install the Stretch version. > > There might be configuration files that also need to be updated, > depending on the application. Not getting this right shouldn't cause > any data loss however. I'd welcome any input into the bug report itself but everything you describe is how it is expected to work. It is not how it is actually working and I believe this is down to how django changed the way that is calculates the dependencies of the migrations. -- Neil Williams ============= http://www.linux.codehelp.co.uk/
Attachment:
pgpkQZ0XFeqvQ.pgp
Description: OpenPGP digital signature