Complete Insert/Update/Delete of Child Entities in Entity Framework

Question

I know it has been asked before, but after long hours of searching and coding I can\'t get to a working and clean approach. Here is what I have:

public class         


        

Answer 1

This is just proof of concept.

Controler have func UpdateModel but it wont work with more complex model which have included child records. Look for TestUpdate.

Rule#1: Every Table have PK Id column.

Rule#2: Every FK have to be set.

Rule#3: Cascade delete need to be set. if you want remove related record.

Rule#4: New Record need to have Id = 0 or better will be Null but Id cant be null.

public class TestController : Controller where T : class
{
    const string PK = "Id";

    protected Models.Entities con;
    protected System.Data.Entity.DbSet model;
    public TestController()
    {
        con = new Models.Entities();
        model = con.Set();
    }

    // GET: Default
    public virtual ActionResult Index()
    {
        ViewBag.Result = TempData["Result"];
        TempData["Result"] = null;

        var list = model.ToList();
        return View(list);
    }

    [HttpGet]
    public virtual ActionResult AddEdit(string id)
    {
        int nId = 0;
        int.TryParse(id, out nId);

        var item = model.Find(nId);
        return View(item);

    }

    [HttpPost]
    public virtual ActionResult AddEdit(T item)
    {
        TestUpdate(item);

        con.SaveChanges();

        return RedirectToAction("Index");
    }

    [HttpGet]
    public virtual ActionResult Remove(string id)
    {
        int nId = 0;
        int.TryParse(id, out nId);
        if (nId != 0)
        {
            var item = model.Find(nId);
            con.Entry(item).State = System.Data.Entity.EntityState.Deleted;
            con.SaveChanges();
        }
        return Redirect(Request.UrlReferrer.ToString());
    }

    private void TestUpdate(object item)
    {
        var props = item.GetType().GetProperties();
        foreach (var prop in props)
        {
            object value = prop.GetValue(item);
            if (prop.PropertyType.IsInterface && value != null)
            {
                foreach (var iItem in (System.Collections.IEnumerable)value)
                {
                    TestUpdate(iItem);
                }
            }
        }

        int id = (int)item.GetType().GetProperty(PK).GetValue(item);
        if (id == 0)
        {
            con.Entry(item).State = System.Data.Entity.EntityState.Added;
        }
        else
        {
            con.Entry(item).State = System.Data.Entity.EntityState.Modified;
        }

    }

}

Here is project https://github.com/mertuarez/AspMVC_EF/

You need to create Controler for model and create view for action. In case of AddEdit action you have to create editor Template for subtypes.