title: postgresql total of each column
body: <p>Does someone know in <code>postgresql</code> , how to obtain a sum of a sum ?</p>
  
  <pre><code>SUM(montant) OVER(PARTITION BY code_famille,texte_famille) AS montant
  </code></pre>
  
  <p>I tried this</p>
  
  <pre><code>sum(SUM(montant) OVER(PARTITION BY code_famille,texte_famille) AS montant) as total
  </code></pre>
  
  <p>Wrong syntax.
  Thanks for help.</p>