Sunday, August 28, 2011

Database Migration in Grails

This blog covers the Grails Database Migration Plugin, the official plugin created by Spring Source and based on the popular Liquibase framework. Examples will demonstrate how database migrations can be controlled, managed, and executed. 

Database migrations are an important facet of web development. Preserving existing data while seamlessly adding new functionality and tables is critical when making incremental database changes to production applications. Without a tool to manage database migrations, teams rely on manual sql, error prone communication processes, and costly risk management to implement solutions.

What is a Database Migration

First let's define database migration. Simply put, database migrations are changes to a database that is already running in production, and the customer wants to retain the data for future releases. If this is not the case, then it is sufficient to not really consider it a database migration, and thus, you can rely on GORMs dbCreate configuration.