title: Sequelize Where if not null
body: <p>Lets say I want to do a select command with</p>
  
  <p><code>WHERE ID=2134</code></p>
  
  <p><strong>But</strong> if the user does not provide the id then it should just not bother with the WHERE ID (since it is null)</p>
  
  <p>How can I handle this with Sequelize? </p>