Asp.Net MVC方法

Question

I can't create and update the information by this way: Using Initializer, and Combing two models classes to get the Index View,I have two tables EmployeeInformation & DesignationHierarchy as:

CREATE TABLE [dbo].[DesignationHierarchy](
  [Id] [numeric](18, 0) IDENTITY(1,1) NOT NULL,
  [EmployeeId] [numeric](18, 0) NULL,
  [LineManagerId][numeric](18, 0) NULL
)

&

CREATE TABLE [dbo].[EmployeeInformation](
  [Id] [numeric](18, 0) IDENTITY(1,1) NOT NULL,
  [Name] [nvarchar](255) NULL
)

and ModelClasses as:

public class DesignationHierarchy
{
    public decimal Id { get; set; }
    public decimal EmployeeId { get; set; }
    public decimal LineManagerId { get; set; }

}
public class EmployeeInformation
{
    public decimal Id { get; set; }
    public string Name { get; set; }

}

and

public class EmployeeInformationHierarchy
{
    public EmployeeInformation EmployeeInformation { get; set; }
    public DesignationHierarchy DesignationHierarchy { get; set; }
}

and the methods to Create:

public ActionResult Create()
{
    ViewBag.EmployeeName = new SelectList(db.EmployeeInformation.ToList(),"Id","Name");

    return View();
} 

[HttpPost]
public ActionResult Create(DesignationHierarchy designationHierarchy)
{
    if (ModelState.IsValid)
    {
        db.DesignationHierarchy.Add(designationHierarchy);
        db.SaveChanges();
        return RedirectToAction("Index");  
    }
    return View(designationHierarchy);
}

and edit:

public ActionResult Edit(decimal id)
{
    DesignationHierarchy designationHierarchy = db.DesignationHierarchy.Find(id);
    ViewBag.EmployeeName = new SelectList(db.EmployeeInformation.ToList(), "Id", "Name",designationHierarchy);
    return View(designationHierarchy);
}
[HttpPost]
public ActionResult Edit(DesignationHierarchy designationHierarchy)
{
    if (ModelState.IsValid)
    {
        db.Entry(designationHierarchy).State = EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(designationHierarchy);
}

and for index:

public ViewResult Index()
{
    var designationHierarchy = from d in db.EmployeeInformation
                               join r in db.DesignationHierarchy on d.Id equals r.LineManagerId
                               select new EmployeeInformationHierarchy { EmployeeInformation = d, DesignationHierarchy = r };

    return View(designationHierarchy);
}

and Views:

<div class="editor-label left_align">
    @Html.HiddenFor(model => model.Id)
    @Html.LabelFor(model => model.EmployeeId,"Name")
</div>
<div class="editor-field left_right_padding">
   @Html.DropDownListFor(m => m.EmployeeId, (SelectList)ViewBag.EmployeeName, "--Select Name--")
   @Html.ValidationMessageFor(model => model.EmployeeId)
</div>

<div class="editor-label left_align">
    @Html.LabelFor(model => model.LineManagerId,"Line Manager")
</div>
<div class="editor-field left_right_padding">
   @Html.DropDownListFor(m => m.LineManagerId, (SelectList)ViewBag.EmployeeName, "--Select Name--")
   @Html.ValidationMessageFor(model => model.LineManagerId)
</div>

and view for index:

<td>
    @Html.DisplayFor(modelItem => item.EmployeeInformation.Name)
</td>
<td>
    @Html.DisplayFor(modelItem => item.EmployeeInformation.Name)
</td>
<td>
    @Html.ActionLink("Edit", "Edit", new { id=item.DesignationHierarchy.Id }) |
    @Html.ActionLink("Delete", "Delete", new { id=item.DesignationHierarchy.Id })
</td>

Answer 1

I think the problem could be in your model classes, because you use decimal as primary key. Please try to modify your models as below:

public class DesignationHierarchy
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public decimal Id { get; set; }
    public decimal EmployeeId { get; set; }
    public decimal LineManagerId { get; set; }

}
public class EmployeeInformation
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public decimal Id { get; set; }
    public string Name { get; set; }

}

Note : don't forget to add using System.ComponentModel.DataAnnotations; at the top of your file it's namespace where [DatabaseGenerated(DatabaseGeneratedOption.Identity)] located.

UPDATE:

You wrote that you use Code First, so you have to had context class like this:

 public class MyContext : DbContext 
  { 
    public DbSet<DesignationHierarchy> DesignationHierarchys { get; set; } 
    public DbSet<EmployeeInformation> EmployeeInformations{ get; set; } 
  } 

So could you try this code for you Create and Edit actions?

Here is code for Create :

public ActionResult Create()
{
    ViewBag.EmployeeName = new SelectList(db.EmployeeInformation.ToList(),"Id","Name");

    return View();
} 

[HttpPost]
public ActionResult Create(DesignationHierarchy designationHierarchy)
{
    if (ModelState.IsValid)
    {
       using (var db = new MyContext ()) 
         { 
              db.DesignationHierarchy.Add(designationHierarchy); 
              db.SaveChanges(); 
         } 
         return RedirectToAction("Index"); 
    }
      View(designationHierarchy); 
 }

And for Edit :

public ActionResult Edit(decimal id)
{
    ViewBag.EmployeeName = new SelectList(db.EmployeeInformation.ToList(), "Id", "Name",designationHierarchy);

     using (var db = new MyContext()) 
     { 
            return View(db.DesignationHierarchy.Find(id)); 
     } 
}

[HttpPost]
public ActionResult Edit(DesignationHierarchy designationHierarchy)
{
    if (ModelState.IsValid)
    {
      using (var db = new MyContext()) 
       { 
        db.Entry(designationHierarchy).State = EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
       }
    }
    return View(designationHierarchy);
}

UPDATE 2 : That's really strange. I still think that it could be because of decimal value.

Could you please replace

DesignationHierarchy designationHierarchy = db.DesignationHierarchy.Find(id);

in your Edit Action with

 DesignationHierarchy designationHierarchy = db.DesignationHierarchy
                                               .SingleOrDefault(x=> x.Id == id);

Answer 2

By Changing the datatype of Id to int,and changes in the Views ie in Edit view the Id is kept Hidden using HTML Helper Methods. Still I am having problem to generate a Index View. Though the Remaining answer for my above question is:

DB Script:

    CREATE TABLE [dbo].[DesignationHierarchy](
      [Id] [int] IDENTITY(1,1) NOT NULL,
      [EmployeeId] [numeric](18, 0) NULL,
      [LineManagerId][numeric](18, 0) NULL
    )

Model Class:

    public class DesignationHierarchy
        {
            [Key]
            public int Id { get; set; }
            public decimal EmployeeId { get; set; }
            public decimal LineManagerId { get; set; }

        }

Action Methods:

public ActionResult Create()
{
    ViewBag.EmployeeName = new SelectList(db.EmployeeInformation.ToList(), "Id", "Name");
    ViewBag.LineManagerName = new SelectList(db.EmployeeInformation.ToList(), "Id", "Name");
    return View();
}
[HttpPost]
public ActionResult Create(DesignationHierarchy designationHierarchy)
{
    if (ModelState.IsValid)
    {
        db.DesignationHierarchy.Add(designationHierarchy);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

    return View(designationHierarchy);
} 
public ActionResult Edit(decimal id)
{
    DesignationHierarchy designationHierarchy = db.DesignationHierarchy.Find(id);
    ViewBag.EmployeeName = new SelectList(db.EmployeeInformation.ToList(), "Id", "Name");
    ViewBag.LineManagerName = new SelectList(db.EmployeeInformation.ToList(), "Id", "Name");

    return View(designationHierarchy);
}
[HttpPost]
public ActionResult Edit(DesignationHierarchy designationHierarchy)
{
    if (ModelState.IsValid)
    {
        db.Entry(designationHierarchy).State = EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(designationHierarchy);
}

and Views to Create:

 <div class="editor-label left_align">
            @Html.LabelFor(model => model.EmployeeId, "Name")
        </div>
        <div class="editor-field left_right_padding">
       @Html.DropDownListFor(m => m.EmployeeId, (SelectList)ViewBag.EmployeeName, "--Select Name--")
            @Html.ValidationMessageFor(model => model.EmployeeId)
        </div>
        <div class="editor-label left_align">
            @Html.LabelFor(model => model.LineManagerId, "Line Manager")
        </div>
        <div class="editor-field left_right_padding">
       @Html.DropDownListFor(m => m.LineManagerId, (SelectList)ViewBag.LineManagerName, "--Select Name--")
            @Html.ValidationMessageFor(model => model.LineManagerId)
        </div>

and Edit:

    <div class="editor-label left_align">
      @Html.HiddenFor(model => model.Id)
        @Html.LabelFor(model => model.EmployeeId, "Name")
    </div>
    <div class="editor-field left_right_padding">
   @Html.DropDownListFor(m => m.EmployeeId, (SelectList)ViewBag.EmployeeName, "--Select Name--")
        @Html.ValidationMessageFor(model => model.EmployeeId)
    </div>
    <div class="editor-label left_align">
        @Html.LabelFor(model => model.LineManagerId, "Line Manager")
    </div>
    <div class="editor-field left_right_padding">
   @Html.DropDownListFor(m => m.LineManagerId, (SelectList)ViewBag.LineManagerName, "--Select Name--")
        @Html.ValidationMessageFor(model => model.LineManagerId)
    </div>