title: Where Clause Case Statement
body: <p>How can I have a where clause be based on a variable:</p>
  
  <p>If I have a variable <code>@PrintNum</code> and it has a number I want a different where clause, but it not it is different. See below: Is this possible?</p>
  
  <pre><code>Where PrintNum = @PrintNum
  Else
  Where InvNum = @InvNum, 
  </code></pre>
  
  <p>etc....</p>