Database

Regardless of how you feel about empty strings, you should be aware of the implications of allowing them on objects that will be persisted. While it seems reasonable to expect a database to store the exact value that you give it, that is unfortunately not always the case. If you’re going to allow empty strings on persistent objects, you should take the time to determine the behavior of the database management system you’re using. You should also assess how likely it is that you are going to either have to support multiple databases, or that you will switch to another database management system in the future.

Liquibase is a tool that helps you manage database changes. It can can be integrated into your build process to automatically update your database, and it also has a command line interface that operational staff can use to generate SQL scripts for production deployment. One of its nice features is database abstraction. You define your changesets in XML, and Liquibase generates compatible SQL for you. As with any tool that tries to provide this level of abstraction over a large number of vendors, it doesn’t work 100% with all DBMS. Below is a simple changeset.