title: subquery in FROM must have an alias
body: <p>I have this query I have written in PostgreSQL that returns an error saying:</p>
  
  <blockquote>
    <p>[Err] ERROR:<br>
    LINE 3: FROM (SELECT DISTINCT (identifiant) AS made_only_recharge</p>
  </blockquote>
  
  <p>This is the whole query:</p>
  
  <pre><code>SELECT COUNT (made_only_recharge) AS made_only_recharge
  FROM (
      SELECT DISTINCT (identifiant) AS made_only_recharge
      FROM cdr_data
      WHERE CALLEDNUMBER = '0130'
      EXCEPT
      SELECT DISTINCT (identifiant) AS made_only_recharge
      FROM cdr_data
      WHERE CALLEDNUMBER != '0130'
  )
  </code></pre>
  
  <p>I have a similar query in Oracle that works fine. The only change is where I have <code>EXCEPT</code> in Oracle I have replaced it with the <code>MINUS</code> key word. I am new to Postgres and don't know what it is asking for. What's the correct way of handling this?</p>