Cannot implicitly convert type system linq IQueryable to system collections generic List

Question

Unable to fetch Data from View Model Controller to View,i have properly checked the working of query in LINQpad. However I am missing the conversion of the output of query whic

Answer 1

The extension method .Select will returns a IEnumerable<TResult>, But you are trying to assign them to a business object of type ProductRegistrationViewModelVM such assignment is invalid, either you can change the type of vm to var or you have to make it as List if so the query will be like the following:

List<ProductRegistrationViewModelVM> vm =(from p in db.Products
                   join i in db.Images on p.ProductId equals i.Product_Id
                   join s in db.Specifications on p.ProductId equals s.Product_Id
                   select new ProductRegistrationViewModelVM
                   {
                       //Product
                       p.Name,
                       p.Produt_Code,
                       p.Description,
                       //Image
                       i.Image_Description,
                       i.Image_Name,
                       i.image1,
                       //Specifications
                       s.Sz_Measurement_Unit,
                       s.Size,
                       s.Wg_Measurement_Unit,
                       s.Weight,
                       s.Price_Set,
                       s.Price_Sold
                   }).ToList();

Now you can easily add another object of type ProductRegistrationViewModelVM to this since it a List of the same type. And you should do a small change in return as well. which will be like the following;

return View(vm); // No ToList is needed here since it is already a list

Answer 2

You create a vm like this:

ProductRegistrationViewModelVM  vm = new ProductRegistrationViewModelVM();

Then you assign an IQueryable which returns anonymous types to it. That will not pass. Then you try and add a new instance of your view model to it and that will not work either:

vm.Add(new ProductRegistrationViewModelVM());

Fix

Try this instead:

var vm = ( from p in db.Products
         join i in db.Images on p.ProductId equals i.Product_Id
         join s in db.Specifications on p.ProductId equals s.Product_Id
         select new ProductRegistrationViewModelVM
         {
            //Product
            p.Name,
            p.Produt_Code,
            p.Description,
            //Image
            i.Image_Description,
            i.Image_Name,
            i.image1,
            //Specifications
            s.Sz_Measurement_Unit,
            s.Size,
            s.Wg_Measurement_Unit,
            s.Weight,
            s.Price_Set,
            s.Price_Sold
         } );

return View( vm.ToList() );

And make sure your view accepts a Model as List<ProductRegistrationViewModelVM>.