title: Store a list in a variable in Oracle SQL
body: <p>How to store a list in a variable and use it later in different parts of SQL?</p>
  <p>I have a sql like this
  As shown the list content is duplicated.
  I tried to use <code>DECLARE</code> or <code>DEFINE</code> but seems like it is not for this case</p>
  <pre><code>SELECT 
      l.cod
  FROM list l
  WHERE l.cod IN ( '1999', '1998', '1997' ...) --- same list
  
  UNION
  
  SELECT 
     l.cod
  FROM list l JOIN blablabla.... 
  WHERE l.cod IN ( '1999', '1998', '1997' ...) --- same list
      
  </code></pre>
  <p>How can I solve this in a better way?</p>