The primary key is a string (nvarchar) and I’m not sure how to identify a record in this instance.

I cannot use the following as it is not an integer:

 public ActionResult Details(int Id = 0)
        {

            return View(db.Consultants.Find(Id));
        }

Thx

Hi,

The key can be any type, not only "Id".

Here an example:
Controller:

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;
using PersonEntity.Model;

namespace EstateAgency.Admin.Controllers
{
    public class ProductPhotoSetsController : Controller
    {
        private PersonEntityDbContext db = new PersonEntityDbContext();

        // GET: ProductPhotoSets
        public ActionResult Index()
        {
            var productPhotoSets = db.ProductPhotoSets.Include(p => p.Product).Include(p => p.ProductPhoto);
            return View(productPhotoSets.ToList());
        }

        // GET: ProductPhotoSets/Details/5
        public ActionResult Details(int? productId, int? photoId)
        {
            if (productId == null && photoId == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }

            int idProduct = Convert.ToInt32(productId);
            int idPhoto = Convert.ToInt32(photoId);
            ProductPhotoSet productPhotoSet = db.ProductPhotoSets.Where(p => p.ProductId == idProduct).Where(q => q.PhotoId == idPhoto).SingleOrDefault(); 
            if (productPhotoSet == null)
            {
                return HttpNotFound();
            }
            return View(productPhotoSet);
        }

        // GET: ProductPhotoSets/Create
        public ActionResult Create()
        {
            ProductPhotoSet productPhotoSet = new ProductPhotoSet();
            productPhotoSet.ModifiedDate = DateTime.Now;
            ViewBag.ProductId = new SelectList(db.Products, "Id", "Name");
            ViewBag.PhotoId = new SelectList(db.ProductPhotoes, "Id", "PhotoFileName");
            return View(productPhotoSet);
        }

        // POST: ProductPhotoSets/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "ProductId,PhotoId,Title,Caption,Primary,ModifiedDate")] ProductPhotoSet productPhotoSet)
        {
            productPhotoSet.ModifiedDate = DateTime.Now;
            if (ModelState.IsValid)
            {
                db.ProductPhotoSets.Add(productPhotoSet);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            ViewBag.ProductId = new SelectList(db.Products, "Id", "Name", productPhotoSet.ProductId);
            ViewBag.PhotoId = new SelectList(db.ProductPhotoes, "Id", "PhotoFileName", productPhotoSet.PhotoId);
            return View(productPhotoSet);
        }

        // GET: ProductPhotoSets/Edit/5
        public ActionResult Edit(int? productId, int? photoId)
        {
            if (productId == null && photoId == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            int idProduct = Convert.ToInt32(productId);
            int idPhoto = Convert.ToInt32(photoId);
            ProductPhotoSet productPhotoSet = db.ProductPhotoSets.Where(p => p.ProductId == idProduct).Where(q => q.PhotoId == idPhoto).SingleOrDefault(); 

            if (productPhotoSet == null)
            {
                return HttpNotFound();
            }
            ViewBag.ProductId = new SelectList(db.Products, "Id", "Name", productPhotoSet.ProductId);
            ViewBag.PhotoId = new SelectList(db.ProductPhotoes, "Id", "PhotoFileName", productPhotoSet.PhotoId);
            return View(productPhotoSet);
        }

        // POST: ProductPhotoSets/Edit/5
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit([Bind(Include = "ProductId,PhotoId,Title,Caption,Primary,ModifiedDate")] ProductPhotoSet productPhotoSet)
        {
            productPhotoSet.ModifiedDate = DateTime.Now;
            if (ModelState.IsValid)
            {
                db.Entry(productPhotoSet).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            ViewBag.ProductId = new SelectList(db.Products, "Id", "Name", productPhotoSet.ProductId);
            ViewBag.PhotoId = new SelectList(db.ProductPhotoes, "Id", "PhotoFileName", productPhotoSet.PhotoId);
            return View(productPhotoSet);
        }

        // GET: ProductPhotoSets/Delete/5
        public ActionResult Delete(int? productId, int? photoId)
        {
            if (productId == null && photoId == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            int idProduct = Convert.ToInt32(productId);
            int idPhoto = Convert.ToInt32(photoId);
            ProductPhotoSet productPhotoSet = db.ProductPhotoSets.Where(p => p.ProductId == idProduct).Where(q => q.PhotoId == idPhoto).SingleOrDefault();
            
            if (productPhotoSet == null)
            {
                return HttpNotFound();
            }
            return View(productPhotoSet);
        }

        // POST: ProductPhotoSets/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public ActionResult DeleteConfirmed(int productId, int photoId)
        {
            if (productId == null && photoId == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            ProductPhotoSet productPhotoSet = db.ProductPhotoSets.Where(p => p.ProductId == productId).Where(q => q.PhotoId == photoId).SingleOrDefault();
            db.ProductPhotoSets.Remove(productPhotoSet);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                db.Dispose();
            }
            base.Dispose(disposing);
        }
    }
}

Is called at the Index.cshtml:

        <td>
            @Html.ActionLink("Edit", "Edit", new { ProductId = item.ProductId, PhotoId = item.PhotoId }) |
            @Html.ActionLink("Details", "Details", new { ProductId = item.ProductId, PhotoId = item.PhotoId }) |
            @Html.ActionLink("Delete", "Delete", new { ProductId = item.ProductId, PhotoId = item.PhotoId })
        </td>

The point is under the @Html.ActionLink at this part: 

new { ProductId = item.ProductId, PhotoId = item.PhotoId }

In your case can be:

@Html.ActionLink("Details", "Details", new { YourPrimaryKey = item.YourPrimaryKey})

And at the controller:

        public ActionResult Details(string yourPrimaryKey)
        {
            if (yourPrimaryKey == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }




            return View(yourModel);
        }

Hope can help, have fun.

Thank you sooo much.