title: How to use IS NULL in a parametrized query (Delphi)
body: <p>I got statements like this:</p>
  
  <pre><code>SELECT * From Table WHERE Feld IS NULL
  SELECT * From Table WHERE Feld IS NOT NULL
  </code></pre>
  
  <p>Now I'm wondering how I could parametrize this query:</p>
  
  <pre><code>SELECT * From Table WHERE Feld IS :Value
  </code></pre>
  
  <p>As I cannot pas 'NOT NULL' to a parameter, I think thats not possible at all - but maybe somebody knows a solution for that?
  Thanks!</p>