DataContext.cs

public class DataContext : DbContext, IDataContext
{

   public DbSet<Customer> Customers { get; set; }

   public Customer FetchTableData()
   {
            var query = (from a in Customers
                         where a != null
                         select a).FirstOrDefault();

            return query;
   }

}

IDataContext.cs

public interface IDataContext
{
        Customer FetchTableData();

}

MainController.cs

private IDataContext _context;

   public MainController(IDataContext context)
   {
            _context = context;
   }

   public IActionResult MainPage()
   {

            var getData = _context.FetchTableData().Name;
            ViewData["DisplayName"] = getData;

            return View();

   }