Question

I’m running into an issue in the View with pulling data from different entities. Basically I have a bridging entity CategoryProduct that brings together Category and Product data together. What I want to ultimately display is a list of products and for each of those products – their categories. However I’m completely stuck on how to make that last part – display categories – happen.

Here’s the code for my model –

public class Product
    {   
        public int ProductId { get; set; }
        public string Title { get; set; }
        public virtual ICollection<CategoryProduct> CategoryProducts { get; set; }
    }

    public class CategoryProduct
    {
        public int CategoryProductID { get; set; }
        public int CategoryId { get; set; }
        public int ProductId { get; set; }
        public virtual Product Product { get; set; }
        public virtual Category Category { get; set; }
    }

    public class Category
    {
        public int CategoryId { get; set; }
        public string Title { get; set; }
        public virtual ICollection<CategoryProduct> CategoryProducts { get; set; }
    }

My Controller is pretty simple, it’s just pushing that bridging entity to the View:

public ActionResult Index()
{
    return View(db.CategoryProducts.ToList());
}

Finally my view displays Products and Categories but right now it’s just creating extra rows for the same product if it has a different category, e.g. Product 1: Category 1, Product 1: Category 2 and so on. And Where I want to get to is Product 1: Category 1, Category 2.

@model IEnumerable<ProductsCode.Models.CategoryProduct>
<h2>Index</h2>
<table>
    <tr>
        <th>Title</th>
        <th>Category</th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Product.Title)
        </td>
        <td>
           @foreach (var categories in item)
           {
             @Html.DisplayFor(modelItem => item.Why.Title)            
           }   
        </td>
    </tr>
}
</table>

Errors out on: Compiler Error Message: CS1579: foreach statement cannot operate on variables of type ‘ProductsCode.Models.CategoryProduct’ because ‘ProductsCode.Models.CategoryProduct’ does not contain a public definition for ‘GetEnumerator’

EDIT: added the other foreach loop and the error.

Answer 1

Why can’t you just change the viewmodel something like this

 public class MyProduct
    {   
        public int ProductId { get; set; }
        public string Title { get; set; }
        public virtual ICollection<Category> CategoryList { get; set; }
    }

and view

@model IEnumerable<ProductsCode.Models.MyProduct>
<h2>Index</h2>
<table>
    <tr>
        <th>Product</th>
        @Html.DisplayFor(modelItem => item.ProductId) 
        <th>Categories for Product</th>
    </tr>

@foreach (var item in Model.CategoryList) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Title)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.CategoryId)
        </td>
    </tr>
}
</table>