ใช้และย้อนกลับด้วย upgrade

You have a migration file, but the database has not changed yet. One command turns that script into real tables. 🚀

flask db upgrade runs every pending migration and brings your database up to the latest version in order.

Behind the scenes Alembic executes the upgrade function inside each pending script, applying its create and alter operations.

After a successful run, the new revision id is saved in the alembic_version table so Alembic remembers where you are.

upgrade is smart: it skips migrations already applied and runs only the pending ones, so re-running it is safe.

If a migration went wrong, you do not edit the database by hand. You roll back to a known good version instead.

flask db downgrade reverses the last migration by running its downgrade function, undoing the most recent change.

Both commands accept a target. Pass a revision id to move directly to that exact point in your migration history.

Run flask db current anytime to print the revision your database sits on right now. Great for a quick sanity check.

flask db history lists every migration in order, so you can see the full path from the first revision to the latest.

On deploy you run upgrade as a release step, never migrate. Production simply replays the scripts your team already reviewed.

The last migration broke something. How do you undo just that one change?

You applied changes with flask db upgrade, reversed them with downgrade, and learned to check current and history. 🎉