I would like to insert the appropriate value into my foreign key "TennisClubId"... But I have a problem and I catch a "NullReferenceException"
My code : (simplified)
// POST: /Reservation/Create
[HttpPost]
public ActionResult Create(Reservation createReservation)
{
int id = 0;
var user = User.Identity.Name;
var managers = from c in db.Managers
select c;
foreach (var manager in managers)
{
id = manager.TennisClubID;
}
createReservation.TennisClub.ID = id;// NullReferenceException here (TennisClub.Id is null)
db.Reservations.Add(createReservation);
db.SaveChanges();
}
So, How to insert the appropriate value into a foreign key when I try to create a reservation please ? Thanks in advance
as you are using Entity-framework
, you will need to create an object map the foreign-key relation, in order to associate it with your main object.
Entity-Framework
will (by defualt) provide you will a Collection inside your main object, to reference the one-to-many relation in your table, and this is the key to solve your problem.
consider the following snippet
foreach (var manager in managers)
{
var tennisClubToreference = new TennisClub()
{
Id = manager.TennisClubID;
}
manager.TennisClubs.add(tennisClubToreference);
}
sorry for the not well-formatted code, I'm posting from my iphone, forgive me :)
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.