How to get out values from object when using Projections

Question

How to get out values from object when using Projections. Any suggestions? This is an example of code

var productsGrouped = session.QueryOver<Product>()
.Select(Projections.Group<Product>(p => p.Category),
Projections.Avg<Product>(p => p.UnitPrice),
Projections.Sum<Product>(p => p.UnitsOnStock),
Projections.RowCount())
.List<object[]>(); 

foreach (var product in productsGrouped)
             {
                 Console.WriteLine(product.Category);  //Dont Work
             }

Doesn't Visual Studio tell you which properties are available? — rene, Jun 18 '14 at 08:07
Visual Studio tells no properties! But its is properties in Product — user3635120, Jun 18 '14 at 08:08
have a look [here](http://stackoverflow.com/questions/6140379/can-someone-better-explain-what-projections-are-in-nhibernate) — rene, Jun 18 '14 at 08:14

score 1 · Answer 1 · answered Jun 18 '14 at 08:14

What we do need here, is to use DTO Object

public class ProductDTO
{
    public virtual string Category { get ; set; }
    public virtual decimal UnitPrice { get; set; }
    public virtual decimal UnitsOnStock { get; set; }
    public virtual int RowCount { get; set; }
}

And now we will use the DTO to create alias

ProductDTO dto = null;

var productsGrouped = session.QueryOver<Product>()
    // let's fill projection list with all the SUM, COUNT but als WITH ALIAS
    .Select(Projections.ProjectionList()
        .Add(Projections.Group<Product>(p => p.Category)
            .WithAlias(() => dto.Category))
        .Add(Projections.Avg<Product>(p => p.UnitPrice)
            .WithAlias(() => dto.UnitPrice))
        .Add(Projections.Sum<Product>(p => p.UnitsOnStock)
            .WithAlias(() => dto.UnitsOnStock))
        .Add(Projections.RowCount()
            .WithAlias(() => dto.RowCount))
    )
    // here we instruct NHibernate to convert projection into our object DTO
    .TransformUsing(Transformers.AliasToBean<ProductDTO>())
    // fully typed result
    .List<ProductDTO>();

// now it is fully qualified object
foreach (var product in productsGrouped)
{
    Console.WriteLine(product.Category);  //Dont Work
}

Great to see that;) Enjoy NHibernate, awesome tool! – Radim Köhler Jun 18 '14 at 08:54 — Radim Köhler, Jun 18 '14 at 08:54

How to get out values from object when using Projections

1 Answers1