Question

I have a class product with child collection prices:

public class Product
{
    private ICollection<Price> prices;

    protected Product()
    {
        prices = new List<Price>();
    }
}

The NHibernate mapping looks like this

<xml version="1.0" encoding="utf-8">
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
    <class name="Product" table="Product">

    <id name="id" column="ProductId" access="field">
        <generator class="identity"/>
    </id>

            <bag name="prices" access="field" cascade="all-delete-orphan"  lazy="true">
        <key column="ProductId"/>
        <one-to-many class="Product.Price"/>
    </bag>

        </class>

You can see that the prices-collection is lazily loaded.

Products are loaded like this from database:

public ICollection<Product> ListProducts()
    {
        ISession session = GetCurrentSession();

        return session
            .CreateCriteria(typeof(Product))
            .List<Product>();
    }

The function refers on GetCurrentSession(), which has the following content:

protected ISession GetCurrentSession()
    {
         return sessionProvider.GetCurrentSessionFrom(sessionFactoryConfigName);
    }

When I load products, I would expect that on the place of the Price-Collections in the products is a proxy because the prices have lazy-loading = true. But while debugging, with the Visual Studio watch tool I can view the products and can see the prices-collection with full content (Prices with all their properties). Why is this so?

Answer 1

Since you’ve accessed the Prices property while debugging, the proxy will have loaded the products collection …
That means, you’ve triggered teh lazy loading processs by ‘watching’ the Prices property.

You can see what happens by configuring nhibernate so that the SQL Statements that are executed, are outputted (show_sql configuration option).