http://www.theregister.co.uk/2011/03/15/apple_ios_throttles_web_apps_on_home_screen/

<asp:RangeExpression DataField="ListPrice"
MinType="Inclusive" MaxType="Exclusive">
<asp:ControlParameter ControlID="FromTextBox" />
<asp:ControlParameter ControlID="ToTextBox" />
</asp:RangeExpression>

FromTextBox is the minimum value.

ToTextBox is the maximum value.

In essence…

public class ValidationError : IValidator
{
    private ValidationError(string message)
    {
        ErrorMessage = message;
        IsValid = false;
    }
 
    public string ErrorMessage { get; set; }
 
    public bool IsValid { get; set; }
   
    public void Validate()
    {
        // no action required
    }
 
    public static void Display(string message)
    {
        Page currentPage = HttpContext.Current.Handler as Page;
        currentPage.Validators.Add(new ValidationError(message));
    }
}

ValidationError.Display("Oops, some error occurred.");

'XXX' is not a foreign key column and cannot be used here.

The trick is to not use the name of the foreign key column but rather the name of the auto generated navigation mechanism as mentioned here. I had trouble finding this at mechanism at first, but then realized it defaults to the name of the foreign key from the database.

Hope this saves someone the heartache!

Relevant Schema info:

Loan has a LoanId
LoanDeclines has a LoanId and a DeclineId — It’s the bridge table
DeclineCodes has the DeclineId as well as the textual Description

The query below returns a list of loans with a pipe delimited list of decline code descriptions.

Select  s.loanid, 
        Stuff((
                Select  '|' + DC.Description
                From    LoanDeclines LD
                join DeclineCodes DC on LD.DeclineCodeId = DC.DeclineId
                Where   s.LoanId = LD.loanid
                For XML Path('')
        ), 1, 1, '') As Courses 
From    Loans s

Courtesy of xkcd