As often repeated in this book, maintaining every aspect of getting your application built and deployed to production needs to be maintained in version control. This includes the database too. The database changes need to be integrated pretty much like source code changes.

It is obvious, then, that database definitions and changes are tracked and integrated through files checked into the VCS.

Database migrations make the process of integration the database schema, and the changes made to the database are part of day-to-day development, straightforward, in a CI setup.

When using such tools, migrations are written whenever there are changes to the database. These migrations are like steps needed to move the database from one state to another. They not only perform the change but usually also provide means to roll back the change if needed.

There are many popular database migration tools in the Java world. Flyway is one such example with excellent documentation...