C# entity framework 5 set a property only in create

Question

I have a model with a property called "datetime_inclusion" and I need to set a value for this ONLY when I save the first time, there is a way to do this treatment in the model? I use C# MVC5 and entity framework 5

Answer 1

When you save the first time your object won't have an ID until it gets put into the DB. You can check against this to set your value.

if(myEntity.ObjectID <= 0)
{
    myEntity.DateAdded = DateTime.Now;
}

Answer 2

Shoe's answer is perfect. But if you are worry that property can be change in edit time, control that. In create action use Shoe's code and in Edit action use:

[HttpPost] 
public ActionResult Edit(int id, Model model) 
{ 
     using (var db = new YourEntities()) 
     { 
         //control that, it does not change
         model.datetime_inclusion = db.YourTable.Find(id).datetime_inclusion;

         db.Entry(model).State = System.Data.EntityState.Modified; 
         db.SaveChanges(); 
         return RedirectToAction("Index"); 
     } 
}