title: How does one pass null values to optional parameters in a Business Objects report using the Business Objects SDK?
body: <p>I am building a web front end for accessing Business Objects reports using the Business Objects SDK for .NET.  I have been able to hack my way through 95% of the business requirements with the sparse documentation and forum posts available online for the topic.  My final roadblock centers on working with parameterized reports.  Our business has situations in which a report has two parameters and the end user is only requried to populate one of them.  It's easy enough to collect and cleanse this data, but no matter how I try to pass the null valued parameter to the reports, I get no data back.  If both parameters are populated I DO get the expected data.  When stepping through the code in Visual Studio I see that whenever BusinessObjects returns a null valued parameter it displays as an empty string (""). I have tried passing this as a parameter value and have also tried assigning the parameter a value of null.  Neither of these options returns results once the report is scheduled and run.  I have an example of my parameter assignment code below using each of the approaches that I've taken (We need to check for a string valued "null" as the user's have requested the ability to type "null" and have that passed to the report).  None of these produce a report that contains data.</p>
  
  <pre><code>sVal.Value = param.ParameterValue != "null" ? param.ParameterValue : String.Empty; 
  sVal.Value = param.ParameterValue != "null" ? param.ParameterValue : "";
  sVal.Value = param.ParameterValue != "null" ? param.ParameterValue : null;
  </code></pre>
  
  <p>Is there a specific value that the Enterprise Server uses to indicate null, such as dates are required to be wrapped in Date()? </p>
  
  <p>Edit:  The functionality I need to duplicate as seen in InfoView:
  <img src="https://i.stack.imgur.com/lyv04.png" alt="Image of null parameter option in InfoView"></p>