title: mySQL query for empty and NULL value together
body: <p>In a database, among the fields, I have two fields which are <code>picName</code> and <code>UserName</code>.
  The <code>picName</code> can have a <code>NULL</code> value, a picture's name or it can be <strong>empty</strong>.</p>
  
  <p>I want to query the <code>userName</code> of those entries whose <code>picName</code> is either <code>NULL</code> or <strong>empty</strong>.</p>
  
  <p>I tried these commands separately</p>
  
  <pre><code>Select userName from user where picName = ''
  
  Select userName from user where picName IS NULL
  </code></pre>
  
  <p>But I want to get both the results in 1 query.</p>
  
  <p>I tried using <code>IN</code> operator like this</p>
  
  <pre><code>Select userName from user where picName IN ('' , IS NULL)
  </code></pre>
  
  <p>But it didn't work.</p>
  
  <p>How should I do it...?</p>