title: No mapping exists from object type System.RuntimeType to a known managed provider native type
body: <p>I have a stored procedure with the signature</p>
  
  <pre><code>PROCEDURE [dbo].[spValidateID]
      @ScanCode       VARCHAR(50),
      @Name           VARCHAR(50) = NULL OUTPUT,
      @ScanTime       DATETIME = NULL OUTPUT,
      @ValidationCode INT = 0 OUTPUT
  </code></pre>
  
  <p>This is supposed to return a validationCode and also populate the name and scanTime variables.
  I need to give it scanCode value while calling.</p>
  
  <p>in my C#  code I am doing like this.</p>
  
  <pre><code>using (var context = new DBEntities())
  {
      var pScanCode = new SqlParameter("ScanCode", scanCode);
      var opName = new SqlParameter("Name", name);
      var opScanTime = new SqlParameter("ScanTime", scanTime);
      var opValidationCode = new SqlParameter("ValidationCode", validationCode);
  
      var test = context.ExecuteStoreQuery&lt;int&gt;("spValidateID @ScanCode, @Name, @ScanTime, @ValidationCode", pScanCode, opName, opScanTime, opValidationCode);
  }
  </code></pre>
  
  <p>but while running this I m getting error 
   No mapping exists from object type System.RuntimeType to a known managed provider native type.</p>
  
  <p>any idea??</p>