Why do Entity Framework queries not return unsaved entities
Consider the following code:
var Products_First = (from Entities.Product p in myContext.Product
select p);
Entities.Product newProduct = new Entities.Product();
newProduct.Name = "New Product";
myContext.Products.AddObject(newProduct);
var Products_Again = (from Entities.Product p in myContext.Product
开发者_如何学JAVA select p);
Notice here that Products_Again
is queried without saving the context, that is myContext.SaveChanges()
is not called.
Products_Again
contains the same number of products as Products_First
. Why is this? A new Product
is added and tracked by the same context object. Why can not I see the new product in the new query results?
After adding new object to the context is there a way to reach the new object without saving changes?
Properties of type ObjectQuery<T>
, like myContext.Product
, always query the DB. That's what they do.
In EF 4.1 you can use DbSet<T>.Local
to query memory.
In EF < 4.1 you would use:
ObjectContext.ObjectStateManager.GetObjectStateEntries(EntityState.Added).Select(o => o.Entity).OfType<Product>()
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