title: like '%' does not accept NULL value
body: <p>I have query that is build from user's inputs ( passed via html form). It looks like (simple example):</p>
  
  <pre><code>Select * From [table] Where [table].[column] like '&lt;parameter&gt;'
  </code></pre>
  
  <p>This parameter may be optional so if user left corresponding input field empty I pass <strong>%</strong>. It worked fine until I encountered NULL values. I understand that '%' match symbols not null, but i would like to consider NULL as empty string in this case.</p>
  
  <p>What should I do? Change query (how?) or pass another symbol(s) when user left empty input?</p>
  
  <p>Thanks.</p>
  
  <p><strong>PS.</strong> It's real problem from existing system and i know it's far from optimal solution, but i have to deal with it.</p>