Direct Alembic to ignore the sqlite_sequence table

[Andrew-Dickinson]

I believe this fixes both of the database concerns raised in #553:

Starting from this change, when I use alembic to create a new automatic migration (to test something for #557 ), it picks up something strange even if I don't touch the models:

$ python -m ihatemoney.manage db migrate -d ihatemoney/migrations -m test-after-history
INFO  [alembic.autogenerate.compare] Detected removed table 'sqlite_sequence'
  Generating /home/dev/tmp/ihatemoney/ihatemoney/migrations/versions/9c340fd31fff_test_after_history.py ...  done

and

Now I remember that Alembic was giving me a warning about not taking into account ALTER while applying the migration:

INFO  [alembic.runtime.migration] Running upgrade a67119aa3ee5 -> 6c6fb2b7f229, empty message
INFO  [alembic.runtime.migration] Running upgrade 6c6fb2b7f229 -> 2dcb0c0048dc, autologger
/dev/venv3-ihatemoney/lib/python3.8/site-packages/alembic/ddl/sqlite.py:40: UserWarning: Skipping unsupported ALTER for creation of implicit constraint
Please refer to the batch mode feature which allows for SQLite migrations using a copy-and-move strategy.
INFO  [alembic.runtime.migration] Running upgrade 2dcb0c0048dc -> cb038f79982e, sqlite_autoincrement

By directing Alembic to ignore the SQLite built-in table "sqlite_sequence", which according to the documentation is managed automatically by SQLite

[zorun]

Thanks, it fixed the spurious migration detection Detected removed table 'sqlite_sequence' 👍

However the Skipping unsupported ALTER warning is still there when applying the sqlite_autoincrement migration. If you think that the warning can be ignored, it's fine, because the main issue was the spurious migration.

[Andrew-Dickinson]

I did a bit more digging and discovered that the Skipping unsupported ALTER warning was actually coming from the enum type in the autologger migration. By wrapping it in a batch migration I believe that I've fixed it

[zorun]

Ah right, my bad! The warning is indeed gone 👍