c# - how to deal with 2 entangled tables of a database? -

i'm trying learn asp.net web forms following "wingtip toys" tutorial made microsoft. in project, create database has 2 tables: "products" & "category". each product has category:

namespace wingtiptoys.models {   public class product   {     [scaffoldcolumn(false)]     public int productid { get; set; }      [required, stringlength(100), display(name = "name")]     public string productname { get; set; }      .     .     .      public int? categoryid { get; set; }      public virtual category category { get; set; }   }  public class category   {     [scaffoldcolumn(false)]     public int categoryid { get; set; }      [required, stringlength(100), display(name = "name")]     public string categoryname { get; set; }      public virtual icollection<product> products { get; set; }   } } 

then create 2 tables:

public class productcontext : dbcontext {     public productcontext() : base("wingtiptoys")     {     }     public dbset<category> categories { get; set; }     public dbset<product> products { get; set; } } 

and there 2 methods: "getcategory" & "getproduct"

public class productdatabaseinitializer : dropcreatedatabaseifmodelchanges<productcontext> { protected override void seed(productcontext context) {   getcategories().foreach(c => context.categories.add(c));   getproducts().foreach(p => context.products.add(p)); }  private static list<category> getcategories() {   var categories = new list<category> {             new category             {                 categoryid = 1,                 categoryname = "cars"             },             .             .             .             new category             {                 categoryid = 5,                 categoryname = "rockets"             },         };    return categories; }  private static list<product> getproducts() {   var products = new list<product> {             new product             {                 productid = 1,                 productname = "convertible car",                 description = "this convertible car fast! engine powered neutrino based battery (not included)." +                                "power , let go!",                  imagepath="carconvert.png",                 unitprice = 22.50,                 categoryid = 1             },             .             .             .             new product             {                 productid = 16,                 productname = "rocket",                 description = "this fun rocket travel height of 200 feet.",                 imagepath="rocket.png",                 unitprice = 122.95,                 categoryid = 5             }         };    return products; } } 

you can see code here @ microsoft page. use "listview" "selectmethod=getproduct" show products client category in "products list" page (here, middle of page), , clicking on product, show it's details in "product details" page (link above, end of age).

now have idea : want assign "imagepath" property each category show image background of "product details" page. example, if product "boat" category, want background boat.jpg, etc.

[display(name = "imagepath")] public string imagepath { get; set; } 

as mentioned (and can see in microsoft page above), each product has category , each category has imagepath, tried code path (please see links above understand i'm saying! ):

<%#:item.category.imagepath%> 

there no error before compiling code, when press f5 debug project one:

system.invalidoperationexception: there open datareader associated command must closed first. 

how can deal it?

edit: exact question: how "imagepath" "category" table while using "getproduct" list view "selectmethod" dealing "products" table?