diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 28c3cae..119722d 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -25,10 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
-
-
 /**
  * SQLite Database Adapter Class
  *
@@ -44,30 +40,29 @@
  */
 class CI_DB_sqlite_driver extends CI_DB {
 
-	var $dbdriver = 'sqlite';
+	public $dbdriver = 'sqlite';
 
 	// The character used to escape with - not needed for SQLite
-	var $_escape_char = '';
+	protected $_escape_char = '';
 
 	// clause and character used for LIKE escape sequences
-	var $_like_escape_str = " ESCAPE '%s' ";
-	var $_like_escape_chr = '!';
+	protected $_like_escape_str = ' ESCAPE \'%s\' ';
+	protected $_like_escape_chr = '!';
 
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
 	 * used for the count_all() and count_all_results() functions.
 	 */
-	var $_count_string = "SELECT COUNT(*) AS ";
-	var $_random_keyword = ' Random()'; // database specific random keyword
+	protected $_count_string = 'SELECT COUNT(*) AS ';
+	protected $_random_keyword = ' Random()'; // database specific random keyword
 
 	/**
 	 * Non-persistent database connection
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_connect()
+	public function db_connect()
 	{
 		if ( ! $conn_id = @sqlite_open($this->database, FILE_WRITE_MODE, $error))
 		{
@@ -89,10 +84,9 @@
 	/**
 	 * Persistent database connection
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_pconnect()
+	public function db_pconnect()
 	{
 		if ( ! $conn_id = @sqlite_popen($this->database, FILE_WRITE_MODE, $error))
 		{
@@ -117,12 +111,11 @@
 	 * Keep / reestablish the db connection if no queries have been
 	 * sent for a length of time exceeding the server's idle timeout
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function reconnect()
+	public function reconnect()
 	{
-		// not implemented in SQLite
+		// Not supported in SQLite
 	}
 
 	// --------------------------------------------------------------------
@@ -130,11 +123,11 @@
 	/**
 	 * Select the database
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @return	bool
 	 */
-	function db_select()
+	public function db_select()
 	{
+		// Not needed, in SQLite every pseudo-connection is a database
 		return TRUE;
 	}
 
@@ -143,14 +136,13 @@
 	/**
 	 * Set client character set
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	string
-	 * @return	resource
+	 * @return	bool
 	 */
-	function db_set_charset($charset, $collation)
+	public function db_set_charset($charset, $collation)
 	{
-		// @todo - add support if needed
+		// Not supported
 		return TRUE;
 	}
 
@@ -159,10 +151,9 @@
 	/**
 	 * Version number query string
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function _version()
+	public function _version()
 	{
 		return sqlite_libversion();
 	}
@@ -172,13 +163,18 @@
 	/**
 	 * Execute the query
 	 *
-	 * @access	private called by the base class
 	 * @param	string	an SQL query
 	 * @return	resource
 	 */
-	function _execute($sql)
+	protected function _execute($sql)
 	{
 		$sql = $this->_prep_query($sql);
+
+		if ( ! preg_match('/^(SELECT|EXPLAIN).+$/i', ltrim($sql)))
+		{
+			return @sqlite_exec($this->conn_id, $sql);
+		}
+
 		return @sqlite_query($this->conn_id, $sql);
 	}
 
@@ -189,11 +185,10 @@
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
-	 * @access	private called by execute()
 	 * @param	string	an SQL query
 	 * @return	string
 	 */
-	function _prep_query($sql)
+	protected function _prep_query($sql)
 	{
 		return $sql;
 	}
@@ -203,18 +198,12 @@
 	/**
 	 * Begin Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_begin($test_mode = FALSE)
+	public function trans_begin($test_mode = FALSE)
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -222,7 +211,7 @@
 		// Reset the transaction failure flag.
 		// If the $test_mode flag is set to TRUE transactions will be rolled back
 		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;
+		$this->_trans_failure = ($test_mode === TRUE);
 
 		$this->simple_query('BEGIN TRANSACTION');
 		return TRUE;
@@ -233,18 +222,12 @@
 	/**
 	 * Commit Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_commit()
+	public function trans_commit()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -258,18 +241,12 @@
 	/**
 	 * Rollback Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_rollback()
+	public function trans_rollback()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -283,12 +260,11 @@
 	/**
 	 * Escape String
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	bool	whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
-	function escape_str($str, $like = FALSE)
+	public function escape_str($str, $like = FALSE)
 	{
 		if (is_array($str))
 		{
@@ -305,9 +281,9 @@
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			$str = str_replace(	array('%', '_', $this->_like_escape_chr),
-								array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
-								$str);
+			return str_replace(array('%', '_', $this->_like_escape_chr),
+						array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
+						$str);
 		}
 
 		return $str;
@@ -318,10 +294,9 @@
 	/**
 	 * Affected Rows
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function affected_rows()
+	public function affected_rows()
 	{
 		return sqlite_changes($this->conn_id);
 	}
@@ -331,10 +306,9 @@
 	/**
 	 * Insert ID
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function insert_id()
+	public function insert_id()
 	{
 		return @sqlite_last_insert_rowid($this->conn_id);
 	}
@@ -347,27 +321,25 @@
 	 * Generates a platform-specific query string that counts all records in
 	 * the specified database
 	 *
-	 * @access	public
 	 * @param	string
-	 * @return	string
+	 * @return	int
 	 */
-	function count_all($table = '')
+	public function count_all($table = '')
 	{
 		if ($table == '')
 		{
 			return 0;
 		}
 
-		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
-
+		$query = $this->query($this->_count_string.$this->_protect_identifiers('numrows').' FROM '.$this->_protect_identifiers($table, TRUE, NULL, FALSE));
 		if ($query->num_rows() == 0)
 		{
 			return 0;
 		}
 
-		$row = $query->row();
+		$query = $query->row();
 		$this->_reset_select();
-		return (int) $row->numrows;
+		return (int) $query->numrows;
 	}
 
 	// --------------------------------------------------------------------
@@ -377,18 +349,18 @@
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	private
-	 * @param	boolean
+	 * @param	bool
 	 * @return	string
 	 */
-	function _list_tables($prefix_limit = FALSE)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SELECT name from sqlite_master WHERE type='table'";
+		$sql = "SELECT name FROM sqlite_master WHERE type='table'";
 
-		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
+		if ($prefix_limit !== FALSE && $this->dbprefix != '')
 		{
-			$sql .= " AND 'name' LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql." AND 'name' LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
+
 		return $sql;
 	}
 
@@ -399,11 +371,10 @@
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @return	string
+	 * @return	bool
 	 */
-	function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
 		// Not supported
 		return FALSE;
@@ -416,13 +387,12 @@
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	string
 	 */
-	function _field_data($table)
+	protected function _field_data($table)
 	{
-		return "SELECT * FROM ".$table." LIMIT 1";
+		return 'SELECT * FROM '.$table.' LIMIT 1';
 	}
 
 	// --------------------------------------------------------------------
@@ -430,10 +400,9 @@
 	/**
 	 * The error message string
 	 *
-	 * @access	private
 	 * @return	string
 	 */
-	function _error_message()
+	protected function _error_message()
 	{
 		return sqlite_error_string(sqlite_last_error($this->conn_id));
 	}
@@ -443,10 +412,9 @@
 	/**
 	 * The error message number
 	 *
-	 * @access	private
-	 * @return	integer
+	 * @return	int
 	 */
-	function _error_number()
+	protected function _error_number()
 	{
 		return sqlite_last_error($this->conn_id);
 	}
@@ -458,11 +426,10 @@
 	 *
 	 * This function escapes column and table names
 	 *
-	 * @access	private
 	 * @param	string
 	 * @return	string
 	 */
-	function _escape_identifiers($item)
+	public function _escape_identifiers($item)
 	{
 		if ($this->_escape_char == '')
 		{
@@ -473,24 +440,20 @@
 		{
 			if (strpos($item, '.'.$id) !== FALSE)
 			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
+				$item = str_replace('.', $this->_escape_char.'.', $item);
 
 				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
 			}
 		}
 
 		if (strpos($item, '.') !== FALSE)
 		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
+			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
 		}
 
 		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
 	}
 
 	// --------------------------------------------------------------------
@@ -501,11 +464,10 @@
 	 * This function implicitly groups FROM tables so there is no confusion
 	 * about operator precedence in harmony with SQL standards
 	 *
-	 * @access	public
 	 * @param	type
 	 * @return	type
 	 */
-	function _from_tables($tables)
+	protected function _from_tables($tables)
 	{
 		if ( ! is_array($tables))
 		{
@@ -522,15 +484,14 @@
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	function _insert($table, $keys, $values)
+	protected function _insert($table, $keys, $values)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -540,7 +501,6 @@
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
@@ -548,24 +508,17 @@
 	 * @param	array	the limit clause
 	 * @return	string
 	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
 	{
 		foreach ($values as $key => $val)
 		{
-			$valstr[] = $key." = ".$val;
+			$valstr[] = $key.' = '.$val;
 		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
+			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
+			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
+			.( ! $limit ? '' : ' LIMIT '.$limit);
 	}
 
 
@@ -578,11 +531,10 @@
 	 * If the database does not support the truncate() command
 	 * This function maps to "DELETE FROM table"
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _truncate($table)
+	protected function _truncate($table)
 	{
 		return $this->_delete($table);
 	}
@@ -594,31 +546,27 @@
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the where clause
 	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
 		$conditions = '';
 
 		if (count($where) > 0 OR count($like) > 0)
 		{
-			$conditions = "\nWHERE ";
-			$conditions .= implode("\n", $this->ar_where);
+			$conditions = "\nWHERE ".implode("\n", $this->ar_where);
 
 			if (count($where) > 0 && count($like) > 0)
 			{
-				$conditions .= " AND ";
+				$conditions .= ' AND ';
 			}
 			$conditions .= implode("\n", $like);
 		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		return "DELETE FROM ".$table.$conditions.$limit;
+		return 'DELETE FROM '.$table.$conditions.( ! $limit ? '' : ' LIMIT '.$limit);
 	}
 
 	// --------------------------------------------------------------------
@@ -628,24 +576,14 @@
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @access	public
 	 * @param	string	the sql query string
-	 * @param	integer	the number of rows to limit the query to
-	 * @param	integer	the offset value
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
 	 * @return	string
 	 */
-	function _limit($sql, $limit, $offset)
+	protected function _limit($sql, $limit, $offset)
 	{
-		if ($offset == 0)
-		{
-			$offset = '';
-		}
-		else
-		{
-			$offset .= ", ";
-		}
-
-		return $sql."LIMIT ".$offset.$limit;
+		return $sql.'LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
 	}
 
 	// --------------------------------------------------------------------
@@ -653,11 +591,10 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
 	 * @param	resource
 	 * @return	void
 	 */
-	function _close($conn_id)
+	protected function _close($conn_id)
 	{
 		@sqlite_close($conn_id);
 	}
@@ -665,6 +602,5 @@
 
 }
 
-
 /* End of file sqlite_driver.php */
-/* Location: ./system/database/drivers/sqlite/sqlite_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/sqlite/sqlite_driver.php */
diff --git a/system/database/drivers/sqlite/sqlite_forge.php b/system/database/drivers/sqlite/sqlite_forge.php
index 2b723be..9976687 100644
--- a/system/database/drivers/sqlite/sqlite_forge.php
+++ b/system/database/drivers/sqlite/sqlite_forge.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -25,8 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * SQLite Forge Class
  *
@@ -39,11 +37,10 @@
 	/**
 	 * Create database
 	 *
-	 * @access	public
 	 * @param	string	the database name
 	 * @return	bool
 	 */
-	function _create_database()
+	public 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
@@ -55,20 +52,16 @@
 	/**
 	 * Drop database
 	 *
-	 * @access	private
 	 * @param	string	the database name
 	 * @return	bool
 	 */
-	function _drop_database($name)
+	public function _drop_database($name)
 	{
 		if ( ! @file_exists($this->db->database) OR ! @unlink($this->db->database))
 		{
-			if ($this->db->db_debug)
-			{
-				return $this->db->display_error('db_unable_to_drop');
-			}
-			return FALSE;
+			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
 		}
+
 		return TRUE;
 	}
 	// --------------------------------------------------------------------
@@ -76,15 +69,14 @@
 	/**
 	 * Create Table
 	 *
-	 * @access	private
 	 * @param	string	the table name
 	 * @param	array	the fields
 	 * @param	mixed	primary key(s)
 	 * @param	mixed	key(s)
-	 * @param	boolean	should 'IF NOT EXISTS' be added to the SQL
+	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
 	 * @return	bool
 	 */
-	function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	public function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
 	{
 		$sql = 'CREATE TABLE ';
 
@@ -94,54 +86,29 @@
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)."(";
+		$sql .= $this->db->_escape_identifiers($table).'(';
 		$current_field_count = 0;
 
-		foreach ($fields as $field=>$attributes)
+		foreach ($fields as $field => $attributes)
 		{
 			// Numeric field names aren't allowed in databases, so if the key is
 			// numeric, we know it was assigned by PHP and the developer manually
 			// entered the field information, so we'll simply add it to the list
 			if (is_numeric($field))
 			{
-				$sql .= "\n\t$attributes";
+				$sql .= "\n\t".$attributes;
 			}
 			else
 			{
 				$attributes = array_change_key_case($attributes, CASE_UPPER);
 
-				$sql .= "\n\t".$this->db->_protect_identifiers($field);
-
-				$sql .=  ' '.$attributes['TYPE'];
-
-				if (array_key_exists('CONSTRAINT', $attributes))
-				{
-					$sql .= '('.$attributes['CONSTRAINT'].')';
-				}
-
-				if (array_key_exists('UNSIGNED', $attributes) && $attributes['UNSIGNED'] === TRUE)
-				{
-					$sql .= ' UNSIGNED';
-				}
-
-				if (array_key_exists('DEFAULT', $attributes))
-				{
-					$sql .= ' DEFAULT \''.$attributes['DEFAULT'].'\'';
-				}
-
-				if (array_key_exists('NULL', $attributes) && $attributes['NULL'] === TRUE)
-				{
-					$sql .= ' NULL';
-				}
-				else
-				{
-					$sql .= ' NOT NULL';
-				}
-
-				if (array_key_exists('AUTO_INCREMENT', $attributes) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
+				$sql .= "\n\t".$this->db->protect_identifiers($field)
+					.' '.$attributes['TYPE']
+					.( ! empty($attributes['CONSTRAINT']) ? '('.$attributes['CONSTRAINT'].')' : '')
+					.(( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE) ? ' UNSIGNED' : '')
+					.(isset($attributes['DEFAULT']) ? ' DEFAULT \''.$attributes['DEFAULT'].'\'' : '')
+					.(( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE) ? ' NULL' : ' NOT NULL')
+					.(( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE) ? ' AUTO_INCREMENT' : '');
 			}
 
 			// don't add a comma on the end of the last field
@@ -153,8 +120,7 @@
 
 		if (count($primary_keys) > 0)
 		{
-			$primary_keys = $this->db->_protect_identifiers($primary_keys);
-			$sql .= ",\n\tPRIMARY KEY (" . implode(', ', $primary_keys) . ")";
+			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->protect_identifiers($primary_keys)).')';
 		}
 
 		if (is_array($keys) && count($keys) > 0)
@@ -163,20 +129,18 @@
 			{
 				if (is_array($key))
 				{
-					$key = $this->db->_protect_identifiers($key);
+					$key = $this->db->protect_identifiers($key);
 				}
 				else
 				{
-					$key = array($this->db->_protect_identifiers($key));
+					$key = array($this->db->protect_identifiers($key));
 				}
 
-				$sql .= ",\n\tUNIQUE (" . implode(', ', $key) . ")";
+				$sql .= ",\n\tUNIQUE (".implode(', ', $key).')';
 			}
 		}
 
-		$sql .= "\n)";
-
-		return $sql;
+		return $sql."\n)";
 	}
 
 	// --------------------------------------------------------------------
@@ -184,18 +148,11 @@
 	/**
 	 * Drop Table
 	 *
-	 *  Unsupported feature in SQLite
-	 *
-	 * @access	private
-	 * @return	bool
+	 * @return	string
 	 */
-	function _drop_table($table)
+	public function _drop_table($table)
 	{
-		if ($this->db->db_debug)
-		{
-			return $this->db->display_error('db_unsuported_feature');
-		}
-		return array();
+		return 'DROP TABLE '.$table.' IF EXISTS';
 	}
 
 	// --------------------------------------------------------------------
@@ -206,7 +163,6 @@
 	 * Generates a platform-specific query so that a table can be altered
 	 * Called by add_column(), drop_column(), and column_alter(),
 	 *
-	 * @access	private
 	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
 	 * @param	string	the column name
 	 * @param	string	the table name
@@ -214,44 +170,25 @@
 	 * @param	string	the default value
 	 * @param	boolean	should 'NOT NULL' be added
 	 * @param	string	the field after which we should add the new field
-	 * @return	object
+	 * @return	string
 	 */
-	function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	public function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
 	{
-		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table)." $alter_type ".$this->db->_protect_identifiers($column_name);
-
-		// DROP has everything it needs now.
-		if ($alter_type == 'DROP')
+		/* SQLite only supports adding new columns and it does
+		 * NOT support the AFTER statement. Each new column will
+		 * be added as the last one in the table.
+		 */
+		if ($alter_type !== 'ADD COLUMN')
 		{
-			// SQLite does not support dropping columns
-			// http://www.sqlite.org/omitted.html
-			// http://www.sqlite.org/faq.html#q11
+			// Not supported
 			return FALSE;
 		}
 
-		$sql .= " $column_definition";
-
-		if ($default_value != '')
-		{
-			$sql .= " DEFAULT \"$default_value\"";
-		}
-
-		if ($null === NULL)
-		{
-			$sql .= ' NULL';
-		}
-		else
-		{
-			$sql .= ' NOT NULL';
-		}
-
-		if ($after_field != '')
-		{
-			$sql .= ' AFTER ' . $this->db->_protect_identifiers($after_field);
-		}
-
-		return $sql;
-
+		return 'ALTER TABLE '.$this->db->protect_identifiers($table).' '.$alter_type.' '.$this->db->protect_identifiers($column_name)
+			.' '.$column_definition
+			.($default_value != '' ? ' DEFAULT "'.$default_value.'"' : '')
+			// If NOT NULL is specified, the field must have a DEFAULT value other than NULL
+			.(($null !== NULL && $default_value !== 'NULL') ? ' NOT NULL' : ' NULL');
 	}
 
 	// --------------------------------------------------------------------
@@ -261,17 +198,15 @@
 	 *
 	 * Generates a platform-specific query so that a table can be renamed
 	 *
-	 * @access	private
 	 * @param	string	the old table name
 	 * @param	string	the new table name
 	 * @return	string
 	 */
-	function _rename_table($table_name, $new_table_name)
+	public function _rename_table($table_name, $new_table_name)
 	{
-		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table_name)." RENAME TO ".$this->db->_protect_identifiers($new_table_name);
-		return $sql;
+		return 'ALTER TABLE '.$this->db->protect_identifiers($table_name).' RENAME TO '.$this->db->protect_identifiers($new_table_name);
 	}
 }
 
 /* End of file sqlite_forge.php */
-/* Location: ./system/database/drivers/sqlite/sqlite_forge.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/sqlite/sqlite_forge.php */
diff --git a/system/database/drivers/sqlite/sqlite_result.php b/system/database/drivers/sqlite/sqlite_result.php
index 74c0dc5..91fe57a 100644
--- a/system/database/drivers/sqlite/sqlite_result.php
+++ b/system/database/drivers/sqlite/sqlite_result.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -25,8 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * SQLite Result Class
  *
@@ -41,10 +39,9 @@
 	/**
 	 * Number of rows in the result set
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function num_rows()
+	public function num_rows()
 	{
 		return @sqlite_num_rows($this->result_id);
 	}
@@ -54,10 +51,9 @@
 	/**
 	 * Number of fields in the result set
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function num_fields()
+	public function num_fields()
 	{
 		return @sqlite_num_fields($this->result_id);
 	}
@@ -69,13 +65,12 @@
 	 *
 	 * Generates an array of column names
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function list_fields()
+	public function list_fields()
 	{
 		$field_names = array();
-		for ($i = 0; $i < $this->num_fields(); $i++)
+		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
 		{
 			$field_names[] = sqlite_field_name($this->result_id, $i);
 		}
@@ -90,22 +85,19 @@
 	 *
 	 * Generates an array of objects containing field meta-data
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function field_data()
+	public function field_data()
 	{
 		$retval = array();
-		for ($i = 0; $i < $this->num_fields(); $i++)
+		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
 		{
-			$F				= new stdClass();
-			$F->name		= sqlite_field_name($this->result_id, $i);
-			$F->type		= 'varchar';
-			$F->max_length	= 0;
-			$F->primary_key = 0;
-			$F->default		= '';
-
-			$retval[] = $F;
+			$retval[$i]			= new stdClass();
+			$retval[$i]->name		= sqlite_field_name($this->result_id, $i);
+			$retval[$i]->type		= 'varchar';
+			$retval[$i]->max_length		= 0;
+			$retval[$i]->primary_key	= 0;
+			$retval[$i]->default		= '';
 		}
 
 		return $retval;
@@ -116,11 +108,11 @@
 	/**
 	 * Free the result
 	 *
-	 * @return	null
+	 * @return	void
 	 */
-	function free_result()
+	public function free_result()
 	{
-		// Not implemented in SQLite
+		// Not supported in SQLite
 	}
 
 	// --------------------------------------------------------------------
@@ -128,14 +120,13 @@
 	/**
 	 * Data Seek
 	 *
-	 * Moves the internal pointer to the desired offset.  We call
+	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
-	 * @access	private
 	 * @return	array
 	 */
-	function _data_seek($n = 0)
+	protected function _data_seek($n = 0)
 	{
 		return sqlite_seek($this->result_id, $n);
 	}
@@ -147,10 +138,9 @@
 	 *
 	 * Returns the result set as an array
 	 *
-	 * @access	private
 	 * @return	array
 	 */
-	function _fetch_assoc()
+	protected function _fetch_assoc()
 	{
 		return sqlite_fetch_array($this->result_id);
 	}
@@ -162,30 +152,20 @@
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @access	private
 	 * @return	object
 	 */
-	function _fetch_object()
+	protected function _fetch_object()
 	{
 		if (function_exists('sqlite_fetch_object'))
 		{
 			return sqlite_fetch_object($this->result_id);
 		}
-		else
-		{
-			$arr = sqlite_fetch_array($this->result_id, SQLITE_ASSOC);
-			if (is_array($arr))
-			{
-				$obj = (object) $arr;
-				return $obj;
-			} else {
-				return NULL;
-			}
-		}
+
+		$arr = sqlite_fetch_array($this->result_id, SQLITE_ASSOC);
+		return is_array($arr) ? (object) $arr : FALSE;
 	}
 
 }
 
-
 /* End of file sqlite_result.php */
-/* Location: ./system/database/drivers/sqlite/sqlite_result.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/sqlite/sqlite_result.php */
diff --git a/system/database/drivers/sqlite/sqlite_utility.php b/system/database/drivers/sqlite/sqlite_utility.php
index f00687e..358fe74 100644
--- a/system/database/drivers/sqlite/sqlite_utility.php
+++ b/system/database/drivers/sqlite/sqlite_utility.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -25,8 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * SQLite Utility Class
  *
@@ -44,16 +42,11 @@
 	 * 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()
+	public function _list_databases()
 	{
-		if ($this->db_debug)
-		{
-			return $this->db->display_error('db_unsuported_feature');
-		}
-		return array();
+		return ($this->db_debug) ? $this->db->display_error('db_unsuported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -61,14 +54,12 @@
 	/**
 	 * Optimize table query
 	 *
-	 * Is optimization even supported in SQLite?
-	 *
-	 * @access	private
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	bool
 	 */
-	function _optimize_table($table)
+	public function _optimize_table($table)
 	{
+		// Not supported
 		return FALSE;
 	}
 
@@ -77,14 +68,13 @@
 	/**
 	 * Repair table query
 	 *
-	 * Are table repairs even supported in SQLite?
 	 *
-	 * @access	private
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	bool
 	 */
-	function _repair_table($table)
+	public function _repair_table($table)
 	{
+		// Not supported
 		return FALSE;
 	}
 
@@ -93,11 +83,10 @@
 	/**
 	 * SQLite Export
 	 *
-	 * @access	private
 	 * @param	array	Preferences
 	 * @return	mixed
 	 */
-	function _backup($params = array())
+	public function _backup($params = array())
 	{
 		// Currently unsupported
 		return $this->db->display_error('db_unsuported_feature');
@@ -105,4 +94,4 @@
 }
 
 /* End of file sqlite_utility.php */
-/* Location: ./system/database/drivers/sqlite/sqlite_utility.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/sqlite/sqlite_utility.php */