system/database/drivers/sqlite/sqlite_utility.php

<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2006, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * SQLite Utility Class
 *
 * @category	Database
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
class CI_DB_sqlite_utility extends CI_DB_utility {

	/**
	 * List databases
	 *
	 * I don't believe you can do a database listing with SQLite
	 * since each database is its own file.  I suppose we could
	 * try reading a directory looking for SQLite files, but
	 * that doesn't seem like a terribly good idea
	 *
	 * @access	private
	 * @return	bool
	 */
	function _list_databases()
	{
		if ($this->db_debug)
		{
			return $this->display_error('db_unsuported_feature');
		}
		return array();
	}

	// --------------------------------------------------------------------

	/**
	 * Optimize table query
	 *
	 * Is optimization even supported in SQLite?
	 *
	 * @access	private
	 * @param	string	the table name
	 * @return	object
	 */
	function _optimize_table($table)
	{
		return FALSE;
	}

	// --------------------------------------------------------------------

	/**
	 * Repair table query
	 *
	 * Are table repairs even supported in SQLite?
	 *
	 * @access	private
	 * @param	string	the table name
	 * @return	object
	 */
	function _repair_table($table)
	{
		return FALSE;
	}

	// --------------------------------------------------------------------

	/**
	 * SQLite Export
	 *
	 * @access	private
	 * @param	array	Preferences
	 * @return	mixed
	 */
	function _backup($params = array())
	{
		// Currently unsupported
		return $this->db->display_error('db_unsuported_feature');
	}

	/**
	 *
	 * The functions below have been deprecated as of 1.6, and are only here for backwards
	 * compatibility.  They now reside in dbforge().  The use of dbutils for database manipulation
	 * is STRONGLY discouraged in favour if using dbforge.
	 *
	 */

	/**
	 * Create database
	 *
	 * @access	public
	 * @param	string	the database name
	 * @return	bool
	 */
	function _create_database()
	{
		// In SQLite, a database is created when you connect to the database.
		// We'll return TRUE so that an error isn't generated
		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Drop database
	 *
	 * @access	private
	 * @param	string	the database name
	 * @return	bool
	 */
	function _drop_database($name)
	{
		if (! @file_exists($this->db->database) OR ! @unlink($this->db->database))
		{
			if ($this->db->db_debug)
			{
				return $this->db->display_error('db_unable_to_drop');
			}
			return FALSE;
		}
		return TRUE;
	}

}