title: retrieving rows in reverse direction from table using sql limit
body: <p>I am implementing pagination using <em>SQL limit</em> in MySQL <code>db.Records</code> are needed to get </p>
  
  <p>retrieved from the last row backwards. There are several thousands records in table </p>
  
  <p>and I want to retrieve say 500 records at a time to show up in a page.</p>
  
  <pre><code>SELECT * FROM tbl_name ORDER BY some_col DESC
  </code></pre>
  
  <p>will retrieve all records.</p>
  
  <p>But I do not want all records, as they are thousands in number.</p>
  
  <p>If I use</p>
  
  <pre><code>SELECT * FROM tbl_name ORDER BY some_col DESC LIMIT 500
  </code></pre>
  
  <p>it will return last 500 records in descending order.</p>
  
  <p>but I could not find a way to retrieve  next block of 500 in reverse direction, starting from a point <strong>where first block have left up.</strong> </p>