upgrade and downgrade expect target to be relative revision

[Lukas0907]

The downgrade and upgrade commands expect the the target revision to always be relative. Therefore, e.g. flask db downgrade 1730111612 would try to revert the last 1730111612 revisions instead of downgrading to the specific revision. Alembic and flask-alembic accept "absolute" revisions as well (cf. https://alembic.sqlalchemy.org/en/latest/tutorial.html#partial-revision-identifiers) so this was surprising to me.

Maybe this could be changed, or mentioned in the docs.

Thanks!

[davidism]

I bet this is an unexpected interaction with making rev_id a timestamp rather than random string. I pretty much only use relative numbers, so I made it unnecessary to enter + or -. When rev id was random, int(rev_id) was unlikely to succeed unless it was intentionally a number and not an id. But now there's no way to distinguish ids from relative numbers.

[Lukas0907]

Right, that makes sense. Using the upstream rev_id() function (basically reverting bd8b43e) seems to restore the old behavior:

from alembic import util as alembic_util

alembic.init_app(app)
alembic.rev_id = alembic_util.rev_id