title: Database-Independent to_char Function in SQLAlchemy
body: <p>I am using SQLAlchemy to make database-independent querys.</p>
  
  <p>I am facing one issue with <code>to_char</code> function. </p>
  
  <p>Consider the simple query like:</p>
  
  <pre><code>select to_char(id,'999') from xyz 
  </code></pre>
  
  <p>It's working on Postgres but MySQL doesn't support it.</p>
  
  <p>How can I make this query database-independent using SQLAlchemy?</p>