title: bison/flex on sql parsing : user entered column name was a keyword
body: <p>I am parsing a sql-like language using bison/flex. If the user entered a column name and it happened was a token/keyword, I got "syntax error". How to do an error handling properly ? For example, the 'from' is a keyword, it should not be used.  The customized action code does not work, because the error was raised before the action was invoked.</p>
  
  <pre><code> create table stayIn (
   from date,
   to date);
  </code></pre>