title: Syntax error when using except in a query
body: <p>This query works:  </p>
  
  <pre><code>mysql&gt; SELECT s.sno FROM students s;  
  +------+  
  | sno  |   
  +------+   
  |    1 |   
  |    2 |   
  |    3 |   
  |    4 |   
  |    5 |    
  |    6 |    
  |    7 |   
  |    8 |   
  |    9 |   
  |   10 |   
  +------+   
  10 rows in set (0.00 sec)  
  </code></pre>
  
  <p>This query also works:  </p>
  
  <pre><code>mysql&gt; SELECT t.sno FROM take t WHERE t.cno = 'CS112';  
  +------+  
  | sno  |  
  +------+  
  |    1 |  
  |    2 |  
  |    3 |  
  |    4 |  
  +------+   
  4 rows in set (0.00 sec)  
  </code></pre>
  
  <p>BUT this query:  </p>
  
  <pre><code>SELECT s.sno FROM students s    
  EXCEPT    
  SELECT t.sno FROM take t WHERE t.cno = 'CS112';  
  </code></pre>
  
  <p>fails with the error:  </p>
  
  <pre><code>mysql&gt; SELECT s.sno FROM students s  
      -&gt; EXCEPT  
      -&gt; SELECT t.sno FROM take t WHERE t.cno = 'CS112';  
  ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that   corresponds to your MySQL server version for the right syntax to use n   
  ear 'EXCEPT   
  SELECT t.sno FROM take t WHERE t.cno = 'CS112'' at line 2 
  </code></pre>
  
  <p>What am I doing wrong here?</p>