Question

I am working on a Silverlight application using RIA services with Entities Framework.

Forgive me, i’m fairly new with Ria services, but how do i go about getting a list of objects from the db without doing a load operation?

Example: I have an Employees table, in this table there’s a IsSupervisor flag. I want to show a list of employees in a grid with a combobox cell bound to a list of supervisors (employees where isSupervisor = true).

The problem i have is that when the list of supervisors come back, the employee list only displays supervisors.

I hope this makes sense….

Answer 1

It’s hard to really say without seeing your code, as RIA Services is pretty darn flexible.

It sounds like you are binding a DataGrid to your DomainContext’s Employee EntitySet, and then making two calls to the server, one to get all employees, then one to get supervisors. If this is the case then yes your second call can wipe out the first one (depends on how you have LoadBehavior set).

But if you are querying the db to get all employees, then you already have the supervisors on the client side. Just create a separate collection that only contains the supervisors, and bind the ComboBox to this. Something like:

private void OnEmployeesLoaded(LoadOperation<Employee> loadOp) {
    if(!loadOp.HasError) {
        Employees = new List<Employee>(loadOp.Entities);
        Supervisors = new List<Employee>(loadOp.Entities.Where(e => e.IsSupervisor));
    }
}