How do I use Fluent Nhibernate many-to-many for optimal performance?

I have a product table that has a many-to-many relation to itself (using a two-column many-to-many table) and I have set it up in Fluent NHibernate with the following code:

public class ProductConfiguration : ClassMap<Product>
{
    public ProductConfiguration()
    {
        Table("Product");
        Id(p => p.Id).GeneratedBy.Guid();

        Map(p => p.Name).Not.Nullable().Length(254);
        Map(p => p.Description).Not.Nullable().Length(1000);
        Map(p => p.CreatedAt).Not.Nullable();

        HasManyToMany(p => p.CrossSell)
            .Table("ProductCrossSell")
            .ParentKeyColumn("Id")
            .ChildKeyColumn("ProductId"); 
    }
}

My MVC application has two pages that uses this setup:

• Index - Uses a generic repository GetAll method to display all products.
• Detail - Uses a generic repository GetById method to display one product and any related cross sell products setup in the many-to-many realation.

It looks like NHibernate is set to LazyLoad the many-to-many by default so when I fire up the application and watch it in profiler I can see that it does LazyLoad the many-to-many with the following alert "Use of implicit transactions is discouraged".

1. How do I get rid of this alert? I couldn't find any information on how to wrap a LazyLoad inside a transaction to get rid the alert. Is it even possible?
2. Is there a way to not lazyload this by telling NHibernate that whenever I ask for GetById make sure to join the tables a get everything in one que开发者_如何学JAVAry? I tried using .Fetch.Join() in the many-to-many mapping but that also affected my GetAll query which now displays a joined result set as well which is incorrect.

What is the best apprach for this kind of simple scenario?

Thanks

1. The way to get rid of the warning is to access the object graph and fully populate the UI elements inside a single transaction.

2. Not by configuration. You can create an HQL query that eager fetches the association and use that query for a specific view. I would stick with lazy loading and not make that optimization unless needed. The HQL would be:

return session.CreateQuery("from ProductionConfiguration pc join fetch pc.CrossSell where pc.Id = ?")
    .SetGuid(0, id)
    .List<ProductConfiguration>();

All collections are lazily loaded in NHibernate by default.

You must be triggering loading with a call of some kind (maybe even with the debugger watches)