Generating Database Schema Script from NHibernate

Question

I have inherited a .NET 2008 MVC application that uses nhibernate. The previous developer didn't get as far as generating a database for this project. I am fairly new to nhibernate, and I am trying to figure out what would be the optimal solution for creating a database script for creating a new database using the current mappings. I have gone through many posts on this site, but still do not understand completely how to get this to work. Any guidance is appreciated.

Thank you!

Answer 1

Assuming you have hbm.xml mappings and a valid nhibernate config file, you could write the following code in a console app to generate the SQL schema:

//load initial config from hibernate config file
Configuration cfg = new Configuration().Configure("hibernate.cfg.xml");

//add assembly in which the hbm.xml mappings are embedded (assuming Product class is in this assembly)
cfg.AddAssembly(typeof(Product).Assembly);

//this will generate the SQL schema file in the executable folder
new SchemaExport(cfg).SetOutputFile("schema.sql").Execute(true, false, false);

If you have fluent mappings, it should look more like this:

Fluently.Configure().Database(MsSqlConfiguration.MsSql2005).Mappings(
            m => m.FluentMappings.AddFromAssemblyOf<Product>()).ExposeConfiguration(
                config =>
                    {
                        new SchemaExport(config).SetOutputFile("schema.sql").Execute(true, false, false);
                    }).BuildConfiguration();