ORM in the realworld

Question

I am begining a new project that i think will last for some years. Am in the point of deciding the ORM framework to use (or whether to use one at all). Can anyone with experience tell me whether orm frameworks are used in realworld applications. The problem i have in mind is this: The orm tool will generate for me tables and columns etc as i create and modify my entities. However, after the project has gone live and is in production, certain database changes will not be possible. Can this hinder the advancement of the project. If i had used a framework like ibatis for example, i know i would only need to adjust the sql statements based on the database changes. Can someone tell me whether ORM tools have survived the live environment. At my office, we use java based ERP that was done long ago and it was never done using any ORM framework.

Regards. Josh

Answer 1

Only use auto generated schema's for the early development and prototyping. The generated DDL will almost never satisfy any experienced DBA. Further the database is properly going to live longer than the current application code, so spending time on its design is usually well worth the effort.

When choosing a mapper go for a flexible one and stay clear of the object-obsessed mappers, since these often only supports limited database customization. Hibernates poor stored procedure integration comes to mind, as does JPAs lack of support for custom type mappers.

Object mappers like IBatis and EclipseLink are safe choices as they allows you to map almost anything, ensuring that you can create both a great domain model and a nifty schema design. Also note that Spring JDBC has come a very long way (in particular the very handy SimpleJDBCTemplate), so while technically not a ORM it does allow you to do anything you want without writing tedious JDBC boilerplate code.