title: SSRS parameter defaults to NULL (All) even though no default value is set
body: <p>I have a SSRS report parameter that is <strong>incorrectly</strong> defaulting to NULL (All), when I have the <em>'No default value'</em> option selected.  The parameter uses a stored procedure to load available values, and there are several values in my parameter drop-down-box.</p>
  <p><a href="https://i.stack.imgur.com/QgVmH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QgVmH.png" alt="Paramater Properties" /></a>
  <a href="https://i.stack.imgur.com/XQ03C.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XQ03C.png" alt="No Default Parameter Selected" /></a></p>
  <p>When I view my report in preview mode or on the SSRS poral, my parameter is automatically set to All (NULL).  What would make this happen?</p>
  <p>The XML code shows no default values either:</p>
  <pre><code>&lt;ReportParameters&gt;
  &lt;ReportParameter Name=&quot;[My Parameter Name]&quot;&gt;
    &lt;DataType&gt;Integer&lt;/DataType&gt;
    &lt;Nullable&gt;true&lt;/Nullable&gt;
    &lt;Prompt&gt;My Parameter&lt;/Prompt&gt;
    &lt;ValidValues&gt;
      &lt;DataSetReference&gt;
        &lt;DataSetName&gt;MyDataSet&lt;/DataSetName&gt;
        &lt;ValueField&gt;MyParameterID&lt;/ValueField&gt;
        &lt;LabelField&gt;MyParameterName&lt;/LabelField&gt;
      &lt;/DataSetReference&gt;
    &lt;/ValidValues&gt;
  &lt;/ReportParameter&gt;
  </code></pre>