Data Migration with Java

1. Changelog

The changelog can be found in src/main/java/config/migration/ To create a new change, you have to do the following:

  • Get the current time in the format YYYYMMDD_HHmmss.

  • Create a new file in /entries named MigrationEntry<formatted-time>.java containing a class extending MigrationEntry.

  • Implement the required methods in your class and follow the JavaDoc.

  • Add the class to the migrationEntryMap attribute in the together with the next Integer key inside the constructor.

2. Development

  • All executed entries are saved in the table migration_changelog. If you delete entries, they get executed again.

  • Test your changes locally first, and only commit changes you are confident that work.

  • Before deploying any database changes to a test server, ask for official permission from the project lead. If the changes don’t get approved, manual rollbacks can be necessary, which are avoidable.

  • If queries fail due to the authorization object being null, call SecurityUtils.setAuthorizationObject() beforehand to set a dummy object.