title: Concatenating strings in PostgreSQL result
body: <p>I have an SQL query like this:</p>
  
  <pre><code>SELECT DISTINCT(id) FROM users WHERE ...
  </code></pre>
  
  <p>and I would like to display the results like that:</p>
  
  <pre><code>user=12355
  user=78949
  user=9898
  user=489891
  </code></pre>
  
  <p>Basically with "user=" prepended. Is it possible to do this with PostgreSQL? I've tried with <code>STRING_AGG('user=', DISTINCT(id))</code> but got an error on <code>DISTINCT(id)</code>. Any idea?</p>