Yet another simple way to associate One-To-One relation and to modify both tables.

There's a sample to associate One-To-One relation and to modify both tables in ASP.NET MVC3.

• Creating a More Complex Data Model for an ASP.NET MVC Application (4 of 10)
• Reading Related Data with the Entity Framework in an ASP.NET MVC Application (5 of 10)

But there is some margin for more CoC. So I describe yet another simple way.

Associate One-To-One relation

1. No descriptions in OnModelCreating
2. Instructor class : same as the original
   

       public class Instructor
       {
           public int InstructorId { get; set; }
           ...
           public virtual OfficeAssignment OfficeAssignment { get; set; }
       }

3. OfficeAssignment class : Use ForeignKey attribute instead of Key attribute
   

       public class OfficeAssignment
       {
           [ForeignKey("Instructor")]
           public int OfficeAssignmentId { get; set; }
           ...
           public virtual Instructor Instructor { get; set; }
       }

Modify both tables of One-To-One relation

There are 4 actions to fix from scaffolded ones. Usgin eager-loading makes actions for modify simple.

• HTTP GET Create action : instantiate OfficeAssignment model
  

          //
          // GET: /Instructors/Create
          public ActionResult Create()
          {
              return View(new Instructor() { OfficeAssignment = new OfficeAssignment() });
          }

• HTTP GET Edit action : eager-load table of OfficeAssignment model
  

          //
          // GET: /Instructors/Edit/5
          public ActionResult Edit(int id)
          {
              Instructor instructor = db.Instructors.Include(i => i.OfficeAssignment).Where(i => i.InstructorId == id).Single();
              return View(instructor);
          }

• HTTP POST Edit action : eager-load table of OfficeAssignment model and use TryUpdateModel utility method
  

          //
          // POST: /Instructors/Edit/5
          [HttpPost]
          public ActionResult Edit(Instructor instructor)
          {
              Instructor instructorToGo = db.Instructors.Include(i => i.OfficeAssignment).Where(i => i.InstructorId == instructor.InstructorId).Single();
              if (TryUpdateModel(instructorToGo))
              {
                  db.SaveChanges();
                  return RedirectToAction("Index");
              }
              else
              {
                  return View(instructorToGo);
              }
          }

• HTTP POST Delete action : eager-load table of OfficeAssignment model
  

          //
          // POST: /Instructors/Delete/5
          [HttpPost, ActionName("Delete")]
          public ActionResult DeleteConfirmed(int id)
          {
              Instructor instructor = db.Instructors.Include(i => i.OfficeAssignment).Where(i => i.InstructorId == id).Single();
              db.Instructors.Remove(instructor);
              db.SaveChanges();
              return RedirectToAction("Index");
          }