title: How to use concatenation '||' with distinct clause of SELECT query?
body: <p>I get a missing expression error when I try,</p>
  
  <pre><code>SELECT 'label1:'||distinct col1 from tab1;
  </code></pre>
  
  <p>Is there a way to get around this error?
  Thanks in advance.</p>
  
  <p>Edit:
  The entire query is:</p>
  
  <pre><code>SELECT 'label1:'||distinct col1 from tab1 order by col1;
  </code></pre>