Mastering Flask Web Development - Second Edition

Database migrations with Alembic

The functionality of web apps changes all the time, and with every new functionality, we need to change the structure of our database. Whether it's adding or dropping new columns or creating new tables, our models will change throughout the life cycle of our app. However, problems quickly arise when the database changes often. When moving our changes from development to production, how can you be sure that you carried over every change without manually comparing each model and its corresponding table? Let's say that you want to go back into your Git history to see whether an earlier version of your app had the same bug that you are now encountering in production. How will you change your database back to the ...