如何删除类似的Alembic版本？

Question

When I am trying to do

alembic upgrade head

I am getting this error:

ERROR [alembic.util.messaging] Online migration expected to match one row when updating '3aae6532b560' to 'a1d8dae7cc' in 'alembic_version'; 2 found
FAILED: Online migration expected to match one row when updating '3aae6532b560'
to 'a1d8dae7cc' in 'alembic_version'; 2 found

alembic current

gives two similar versions of alembic like:

3aae6532b560
3aae6532b560

How do I delete one of the similar versions of alembic, ie a copied version?

alembic history doesn't show any messed up output.

Thanks!

Answer 1

Alembic version is stored within your database in alembic_version table. I see that you have two self same rows inside the table.

You can do something like this:

DELETE FROM alembic_version WHERE version_num='3aae6532b560';
INSERT INTO alembic_version VALUES ('3aae6532b560');

Above query could be done in one query by limiting number of deleted rows, but limiting within DELETE query is different between different databases engines.