Question

Im trying to return a list to a display template containing data from two tables, i am using the repository pattern, and a viewmodel to pass the data to the view from a LINQ query that returns both objects

is there to define a collection of multiple types in the interface?
For a single type i have used this in the interface,

    IQueryable<CustomerSite> CustomerSites { get; }

then i have my linq query in the repository

public IQueryable<CustomerSite> CustomerSites
    {
        get { return customerSitesTable; }
    }

However since this new query will contain 2 types, both customers and customer sites, how should this collection be defined in the interface?

======UPDATE

I have tried using the .Include (this throws an error stating that there is no definition for include in the Customer entity, not sure if im missing a name space for this?)

I have also tried creating a custom interface,

public interface ICustomersAndSitesRepository
{
    IQueryable<CustomerSite> CustomerSites { get; }
    IQueryable<Customer> Customers { get; }
    IQueryable<ICustomersAndSitesRepository> CustomerAndSites { get; }
}

And this method in the repository

public IQueryable <ICustomersAndSitesRepository> CustomerAndSites
    {
        get { return CustomerAndSites; }
    }

However when i try to pass the collection to the view in the controller like,

public ViewResult List([DefaultValue(1)] int page)
    {

        var customersWithSitesToShow = customersAndSitesRepository.CustomerAndSites;
        var viewModel = new CustomerSitesListViewModel
        {                
            Customers = customersWithSitesToShow.Skip((page - 1) * PageSize).Take(PageSize).ToList(),
            PagingInfo = new PagingInfo
            {
                CurrentPage = page,
                ItemsPerPage = PageSize,
                TotalItems = customersWithSitesToShow.Count()
            }
        };

        return View(viewModel);  //Passed to view as ViewData.Model (or simply model)
    }

I get a conversion error re convreting the repostiory to the view model

Cannot implicitly convert type  'System.Collections.Generic.List<CustomerDatabase.Domain.Abstract.ICustomersAndSitesRepository>' to 'System.Collections.Generic.IEnumerable<CustomerDatabase.WebUI.Models.CustomerViewModel>'. An explicit conversion exists (are you missing a cast?)  

Im defining the viewmodel like

public IEnumerable Customers { get; set; }

Can anyone kindly point me in the right direction?

Answer 1

Assuming that a Customer has many CustomerSite then you’d return an IQueryable<Customer> but use .Include to return the CustomerSites within each Customer.

e.g.

public IQueryable<Customer> GetCustomersAndSites()
{
    return MyEntities.Customers.Include("CustomerSite");
}