grinderofl / fluentmigrator.nhibernate

A tool to generate FluentMigrator migrations from NHibernate.

FluentMigrator.NHibernate

A tool to generate FluentMigrator migrations from NHibernate.

Differences from EF Migrations

• Entity Framework looks at its migration history table to find the most recently applied migrtation. FluentMigrator.NHibernate uses reflection against the assembly containing the migrations.
• Entity Framework uses timestamps as migration numbers; FluentMigrator.NHibernate finds the last migration version in your assembly and increments.
• You have a lot more control over the internals of how migrations are generated. FluentMigrator.NHiberate gives you an opportunity to override how the source & target expression lists are calcuated as well as an opportunity to filter expressions after the differences are calculated.

Usage

Right now there's no tooling for generating migrations akin to dotnet ef migrations .... Right now the most effective way to use the migration generator is to inherit from MigrationConfigurationBase, make sure to set MigrationNamespace and MigrationAssembly in the constructor, and over ride GetConfiguration to return your NHibernate configuration. In a unit test you can then call MyMigrationConfiguration.Generate("MigrationName","Path\To\MigrationsOutputFolder");.

public class MyNHibernateConfig : NHibernate.Cfg.Configuration
{
	public MyNHibernateConfig() : this("Data Source=(local);Database=myapp;Integrated Security=True;")
	{
		
	}
	public MyNHibernateConfig(string connectionString)
	{
		this.DataBaseIntegration(db =>
		{
			db.ConnectionString = connectionString;
			db.Dialect<MsSql2012Dialect>();
		});
		var mapper = new ConventionModelMapper();
		var mapping = mapper.CompileMappingFor(FindEntities());
		AddMapping(mapping);
	}

	private IEnumerable<Type> FindEntities()
	{
		return Enumerable.Empty<Type>();
	}
}
public class MyMigrationsConfiguration : MigrationConfigurationBase
{
	public MyMigrationsConfiguration()
	{
		MigrationAssembly = typeof (MyNHibernateConfig).Assembly;
		MigrationNamespace = "MyMigrationsApp.Domain.Db.Migrations";
	}

	protected override Configuration GetConfiguration()
	{
		return new MyNHibernateConfig();
	}
}