title: SSRS - Pass Null to Multi-Value Parameter
body: <p>I'm in a tough pickle here, using SSRS and trying to feed a NULL value, with others, from a multi-valued parameter into the stored procedure used for the dataset.  </p>
  
  <p>The values the user selects in the multi-value parameter of the report, are fed to a single input parameter in the stored procedure. For example, the multi-value drop down called @Color can feed 'Red','White', and 'Blue' to the stored procedure's '@ColorList' parameter. The stored procedure uses the parameter for SQL statement building functions and gives the result set.  I want to add the NULL value to the multi-value parameter in addition to the values, as some records do not have a Color value.</p>
  
  <p>Unfortunately, I don't have permissions to the modify the stored procedure so I can't use the ISNULL(Value,'') work-around or change anything with the 'IN' syntax. The stored procedure is being executed in the report as follows:</p>
  
  <pre><code> EXEC StoredProc
   @Name = @Name
   @ColorList = @Color
  </code></pre>
  
  <p>@Color is passed using a JOIN expression </p>
  
  <pre><code>=JOIN(Parameters!Color.Value,",")
  </code></pre>
  
  <p>Any suggestions?</p>