Reload an entity and all Navigation Property Association- DbSet Entity Framework

Question

I have a problem with entity association refresh. When I get an entity with like this:

MyContext context = new MyContext();  Person myPerson = context.PersonSet.FirstOrDefault(); String myPersonName = myPerson.Name; Address myPersonAddress = myPerson.Address; 

I got an a person with an association named Address and a property named Name. If I modify manually the datas in database for example the property Name, I have to use the following code to reload my entity:

context.Entry(myPerson).Reload(); 

and I have the new value for Name. But If I do the same for Address it doesn't work. I think it is because Address is an association property. I need to refresh it.

How Can I do to force the reload of Address association (and all other association in Person class) ?

EDIT:

In the same case, a person can have more than one address.

MyContext context = new MyContext();  Person myPerson = context.PersonSet.FirstOrDefault(); String myPersonName = myPerson.Name; List<Address> myPersonAddresses = myPerson.Addresses; 

In this case, it is not a Reference:

context.Entry(myPerson).Reference(p => p.Address).Load(); // Address will be populated with only the new address // this isn't required because I use lazy loading 

but a Collection:

context.Entry(myPerson).Collection(p => p.Addresses).Load(); // Address will be populated with old value and new value 

I need to use this to work:

context.Entry(myPerson).Collection(p => p.Addresses).CurrentValue.Clear(); context.Entry(myPerson).Collection(p => p.Addresses).Load(); 

But it doesn't seem to be a good solution to do this for all my navigation properties!

Answer 1

If you don't use lazy loading, you have the load the new Address explicitly (as you had to load it explicitly (with Include, for example), when you loaded the Person initially):

context.Entry(myPerson).Reload(); // If the person refers to another Address in the DB // myPerson.Address will be null now  if (myPerson.Address == null)     context.Entry(myPerson).Reference(p => p.Address).Load();     // myPerson.Address will be populated with the new Address now 

If you use lazy loading, you don't need the second code block. Nonetheless, you get a new query to the database as soon as you access properties of the new myPerson.Address (like you have a new query in the second code block above) because the first line will mark the navigation property as not loaded if the person refers to a new address in the DB.

This behaviour doesn't depend on whether you have exposed the foreign key in the model class or not.

There doesn't seem to be a way to call some single magic Reload method which would reload and update the whole object graph in one call (similar like there is no single Include to eager load a complete object graph).