Docker - how do you deploy with new DB structural updates?

I’ve pushed my docker to Production and it is running live, but now need to publish a change involving the database.

When I follow these fantastic instructions, everything works except my “backed up” live database contents are not restored. I didn’t delete the tables/columns they were in, I just added more tables and columns in the new update, as well as included some base data for the new deploy.

I’m thinking the combo of me wanting to add data, update the structure, AND keep the old data is my issue.

When I deploy again, how do I keep the existing live data while updating the DB with new structure at the same time? If it is a manual process, any pointers would be appreciated.

PS - Thanks to this fantastic community, and especially from the ever-helpful @ Apple, I have been having great success with Docker in Wappler. Much smoother than trying to get everything working with a local dev environment for me!