使用实体框架和存储库模式从ASP.NET MVC中的多个表中检索数据

Question

I have 2 classes related in my model:

public class Product
{
        public Product()
        {
            this.Additives = new HashSet<Additive>();
        }

        public int Id { get; set; }
        public string Name { get; set; } // refrigerante
        public string CommercialName { get; set; } // nome popular, ex: fanta laranja
        public string Brand { get; set; } // marca, ex: Coca-cola
        public string Details { get; set; } // composicao, ingredientes
        public HalalState HalalState { get; set; } // estado: halal, haram ou desconhecido
        public DateTime? LastUpdate { get; set; } // date e hora do registo

        public ICollection<Additive> Additives { get; set; } // aditivos
        public int ProviderID { get; set; }
}

and

public class Provider { public Provider() { this.Products = new HashSet(); }

   public int ProviderId { get; set; }
   public string OfficialName { get; set; } // nome usado no licenciamento
   public string PopularName { get; set; } // nome popular, mais conhecido
   public int Nuit { get; set; } //identificacao tributaria
   public EstablishmentCategory EstablishmentCategory { get; set; } // tipo de estabelecimento
   public HalalState HalalState { get; set; }
   public DateTime? LastUpdate { get; set; } // date e hora do registo

   public ICollection<Product> Products { get; set; } // lista de produtos halal               
}

I'm trying to load products alongside with its provider name to display in page using Razor engine. Something like:

Product Name (from table A) | Provider Name (from table B) 
Soft drink                  | Coca-Cola
Chips                       | Lays

The method to retrieve products in class ProductsRepository :

public ICollection<Product> ReadAll()
{       
    return context.Products.ToList();
}

I need a way to navigate to OfficialName property of the Provider class, in order to display it alongside another properties of Product in a view.

Answer 1

You should add a navigational property of type Provider to your Product class.

public class Product
{
    // Your existing properties goes here

    public int ProviderID { get; set; }
    public Provider Provider { set;get;}
}

Now you can pass a list of Products to the view and use the Product property when you loop through then in the view

public ActionResult Items()
{
  var data = yourDbContext.Products.ToList();
  return View(data);
}  

Now, in the view

@model IEnumerable<Product>
<table>
  <tr>
      <th>Name</th>
      <th>Provider</th>
  </tr>
  @foreach(var item in Model)
  {
    <tr><td>@item.Name</td><td>@item.Provider.OfficialName</td></tr>
  }
</table>