How do I update an object's foreign key value with LINQ to Entities?

Question

Suppose I have these tables:

Fruits
 - FruitID       INT PK
 - FruitName     NVARCHAR(30)
 - FruitStatusID INT FK: Statuses

Statuses
 - StatusID      INT PK
 - StatusName    NVARCHAR(30)

How do I update both the Fruit's name and its status in the database in these situations?:

1. Update a piece of Fruit that came from a previous L2E call
2. given an integer corresponding to the FruitID (that is, I don't have a full Fruit object in hand to start with)

VB or C# is fine, thanks!

Answer 1

This works but isn't what I was hoping for:

int StatusID = 4; // Some ID
Fruit.FruidIDReference.EntityKey = 
    New EntityKey("MyEntities.Statuses", "StatusID", StatusID)

Surely there's a cleaner way to do this that doesn't require hard-coding strings (which introduces run-time exceptions if I make a typo).

Answer 2

If a Fruit object is passed on to another method, you can:

1. Pass a reference to the context object along with the Fruit and call SaveChanges()

2. Make your edits to the Fruit object in the downlevel method and call SaveChanges() in the calling method (you can check to see if it has been modified if you want to avoid unnecessary DB calls.)

Code:

//Change the name
FruitEntities fe = new FruitEntities();
Fruit f = fe.Friuts.First();
f.FruitName = "NewName";
fe.SaveChanges();

//Get a fruit by ID and change the status
//Statuses will need to be included as an Entity in your model with an association to Fruits
int Id = 2;
int newStatusID = 0;
FruitEntities fe = new FruitEntities();
Fruit f = (from x in fe.Fruits
           where x.FruitID == Id
           select x).First();
Status s = (from y in fe.Statuses
            where y.StatusID = newStatusID
            select y).First();
f.Status = s;
fe.SaveChanges();