Join table in Entity Framework and display other column - asp.net-mvc

Question

I'm trying to make my list to show data from another column instead of its ID, currently they are showing like so:
This is what I work out so far:
Controller:
public class CompanyAdmin
{
public string Id { get; set; }
[Required(AllowEmptyStrings = false)]
[Display(Name = "Company Name")]
public string CompanyName { get; set; }
public virtual List<Certificate> Certificates { get; set; }
public class Certificate
{
[Key]
[Display(Name = "Certificate No.")]
public string CertNo { get; set; }
[Display(Name = "Company")]
public IEnumerable<SelectListItem> Companies { get; set; }
[Required]
public string Company { get; set; }
[Display(Name = "User")]
public IEnumerable<SelectListItem> UserList { get; set; }
[Required]
public string User { get; set; }
public string UploadedBy { get; set; }
[Display(Name = "Description")]
public string CertDescription { get; set; }
[Display(Name = "File Location")]
public string CertFileLocation { get; set; }
[Display(Name = "Last Modified")]
public DateTime LastModifiedDate { get; set; }
}
public class CertificateViewModel
{
[Display(Name = "Certificate No.")]
public string CertNo { get; set; }
public string User { get; set; }
[Display(Name = "User")]
public string UserName { get; set; }
public string Company { get; set; }
[Display(Name = "Company")]
public string CompanyName { get; set; }
[Display(Name = "Description")]
public string CertDescription { get; set; }
[Display(Name = "Last Modified")]
public DateTime LastModifiedDate { get; set; }
}
Here is my controller:
public ActionResult Index()
{
if (User.IsInRole("Admin"))
{
IEnumerable<CertificateViewModel> model = null;
model = (from c in db.CertificateDB
join u in db.Users on c.User equals u.Id
join d in db.CompanyDB on c.Company equals d.Id
select new CertificateViewModel
{
CertNo = c.CertNo,
UserName = u.UserName,
CompanyName = d.CompanyName,
CertDescription = c.CertDescription,
LastModifiedDate = c.LastModifiedDate
}
);
return View(model);
}
else
{
return RedirectToAction("Index", "Home");
}
}
and the view:
#model IEnumerable<IdentitySample.Models.CertificateViewModel>
<table class="table">
<tr>
<th>
#Html.DisplayNameFor(model => model.CertNo)
</th>
<th>
#Html.DisplayNameFor(model => model.Company)
</th>
<th>
#Html.DisplayNameFor(model => model.User)
</th>
<th>
#Html.DisplayNameFor(model => model.CertDescription)
</th>
<th>
#Html.DisplayNameFor(model => model.LastModifiedDate)
</th>
<th></th>
</tr>
#foreach (var item in Model)
{
<tr>
<td>
#Html.DisplayFor(modelItem => item.CertNo)
</td>
<td>
#Html.DisplayFor(modelItem => item.Company)
</td>
<td>
#Html.DisplayFor(modelItem => item.User)
</td>
<td>
#Html.DisplayFor(modelItem => item.CertDescription)
</td>
<td>
#Html.DisplayFor(modelItem => item.LastModifiedDate)
</td>
<td>
#Html.ActionLink("Edit", "Edit", new { id = item.CertNo }) |
#Html.ActionLink("Details", "Details", new { id = item.CertNo }) |
#Html.ActionLink("Delete", "Delete", new { id = item.CertNo })
</td>
</tr>
}
</table>
My Context:
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public ApplicationDbContext()
: base("DefaultConnection", throwIfV1Schema: false)
{
}
static ApplicationDbContext()
{
// Set the database intializer which is run once during application start
// This seeds the database with admin user credentials and admin role
Database.SetInitializer<ApplicationDbContext>(new ApplicationDbInitializer());
}
public override int SaveChanges()
{
try
{
return base.SaveChanges();
}
catch (DbEntityValidationException ex)
{
string errorMessages = string.Join("; ", ex.EntityValidationErrors.SelectMany(x => x.ValidationErrors).Select(x => x.PropertyName + ": " + x.ErrorMessage));
throw new DbEntityValidationException(errorMessages);
}
}
public DbSet<CompanyAdmin> CompanyDB { get; set; }
public DbSet<Certificate> CertificateDB { get; set; }
public static ApplicationDbContext Create()
{
return new ApplicationDbContext();
}
}
But the results keep coming up empty for the 2 join columns, please see screenshot here
Any idea what I've done wrong?

Answer 1

In your query you populate property CompanyName, but in your view you render property Company. Same goes for User in view vs UserName in a query.
Also I recommend adding .ToList() just before you pass the model to your view - this will make sure data is extracted from DB into objects before it is passed to your view:
model = (from c in db.CertificateDB
join u in db.Users on c.User equals u.Id
join d in db.CompanyDB on c.Company equals d.Id
select new CertificateViewModel
{
CertNo = c.CertNo,
UserName = u.UserName,
CompanyName = d.CompanyName,
CertDescription = c.CertDescription,
LastModifiedDate = c.LastModifiedDate
}
).ToList();

Answer 2

You are setting UserName and CompanyName property for your CertificateViewModel in controller action:
UserName = u.UserName,
CompanyName = d.CompanyName,
while in View you are using Company and User property:
<td>
#Html.DisplayFor(modelItem => item.Company)
</td>
<td>
#Html.DisplayFor(modelItem => item.User)
</td>
So you either need to set the Company and User property of your view model in controller or use CompanyName and UserName for rendering in View, if you change the view, change it to use the correct properties :
<td>
#Html.DisplayFor(modelItem => item.CompanyName)
</td>
<td>
#Html.DisplayFor(modelItem => item.UserName)
</td>