Well, i want that my database is created, when its not existing. And when its existing, and i have made changes, i want that it is updated. But i want to keep my data in the database, when i update it. Can anybody help me how to do this? I found the following methods:

SchemaExport(config).Create
SchemaExport(config).Execute
SchemaUpdate(config).Execute

Which one do i have to use??

Additional info: I use Fluent NHibernate. Means i dont have hbm-files... (don't know whether thats important)