title: update with a proc sql
body: <p>It should be an easy one but I'm stuck</p>
  
  <pre><code>Proc sql; 
  
  UPDATE dicofr 
  SET    dicofr.period = correspondance.period 
  FROM   dicofr 
  INNER JOIN correspondance 
  ON dicofr.name_fic = correspondance.name_fic; 
  </code></pre>
  
  <p>I was thinking my update would be done but I got this error instead.</p>
  
  <pre><code>271  proc sql;
  272  update dicofr
  273  set dicofr.period = correspondance.period
             -
             73
             76
  ERROR 73-322: Expecting an =.
  
  ERROR 76-322: Syntax error, statement will be ignored.
  </code></pre>
  
  <p>I've tried with a straight join with a <code>select</code></p>
  
  <pre><code>proc sql;
  SELECT * FROM dicofr INNER JOIN correspondance 
  ON dicofr.nom_fic=correspondance.nom_fic;
  </code></pre>
  
  <p>The select is fine.</p>
  
  <p>How come? </p>
  
  <p>Is my SQL query not correct? I don't think so ...</p>
  
  <p><strong>Edited</strong>: It seems the update I want to do is not possible. Is there a way to do what I want with SAS language?</p>