Get id after add new item by Entity Framework - asp.net-mvc

Question

I need help with Entity Framework.
Controller:
public ActionResult Create([Bind(Prefix = "visit")] visit visit, [Bind(Prefix = "drugsEdition")] IEnumerable<drugsEdition> drugsEdition, [Bind(Prefix = "accessoryEdition")] IEnumerable<accessoryEdition> accessoryEdition, [Bind(Prefix = "servicesEdition")] IEnumerable<servicesEdition> servicesEdition)
{
Models.VisitDetails visitDetails = new Models.VisitDetails();
visitDetails.visit = visit;
if (ModelState.IsValid)
{
db.visit.Add(visit);
if (drugsEdition != null)
{
foreach (var item in drugsEdition)
{
item.idVisit = visit.id;
db.drugsEdition.Add(item);
}
}
if (accessoryEdition != null)
{
foreach (var item in accessoryEdition)
{
item.idVisit = visit.id;
db.accessoryEdition.Add(item);
}
}
if (servicesEdition != null)
{
foreach (var item in servicesEdition)
{
item.idVisit = visit.id;
db.servicesEdition.Add(item);
}
}
db.SaveChanges();
return RedirectToAction("Details", new { id = visit.id });
}
return View(visitDetails);
}
Model:
[Table("servicesEdition")]
public partial class servicesEdition
{
public int id { get; set; }
public int idService { get; set; }
public int idVisit { get; set; }
public double priceSell { get; set; }
[ForeignKey("idService")]
public virtual services services { get; set; }
}
In this code, I added a new visit to the database, and I want get the visit's id after the code line db.visit.Add (visit). When I add new drugsEdition and new accessoryEdition, this code is correct and added good idVisit, but when I addedservicesEdition idVisit = 0. Why 'servicesEdition' doesn't get good idVisit ?

Answer 1

If you add a virtual navigational property of type Visit, EF will get the corresponding visit id and fill that in when it saves a servicesEdition object on your SaveChanges method call.
I would also renaming the foreign key property to VisitId so that the referential integrity works by convention (naming convention) and you do not need to explicitly use the ForeignKey attribute. I would also recommend you to use PascalCasing when writing C# classes( not necessarily needed for your code to work)
public partial class ServicesEdition
{
public int id { get; set; }
public int idService { get; set; }
public int VisitId { get; set; }
public virtual Visit Visit { get; set; }
public double priceSell { get; set; }
[ForeignKey("idService")]
public virtual services services { get; set; }
}
If you do not want to alter the ServicesEdition entity definition like i described above, another option is to call the SaveChanges() method after you add the Visit entity and then you can access the Id property of that.
db.visit.Add(visit);
db.SaveChanges();
var visitId = db.Id;
//Now you can use visitId to save other entities

Answer 2

The issue is db.visit.Add(visit); does not generate id until hit db.SaveChanges();
You could add db.SaveChanges(); after db.visit.Add(visit);.
Or you will save as a graph like Shyju explained.