Unable to cast object of type 'System.DBNull' to type 'System.String`

Question

I got the above error in my app. Here is the original code

public string GetCustomerNumber(Guid id)
{
     string accountNumber = 
          (string)DBSqlHel         


        

Answer 1

I suppose you can do it like this:

string accountNumber = DBSqlHelperFactory.ExecuteScalar(...) as string;

If accountNumber is null it means it was DBNull not string :)