18 files changed, 2609 insertions, 189 deletions
diff --git a/phpBB/includes/db/db_tools.php b/phpBB/includes/db/db_tools.php
index f63ff18cbe..983cdc18ea 100644
--- a/phpBB/includes/db/db_tools.php
+++ b/phpBB/includes/db/db_tools.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2007 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -21,7 +20,6 @@ if (!defined('IN_PHPBB'))
 * Currently not supported is returning SQL for creating tables.
 *
 * @package dbal
-* @note currently not used within phpBB3, but may be utilized later.
 */
 class phpbb_db_tools
 {
@@ -302,10 +300,10 @@ class phpbb_db_tools
 	/**
 	* Constructor. Set DB Object and set {@link $return_statements return_statements}.
 	*
-	* @param phpbb_dbal	$db					DBAL object
+	* @param phpbb_db_driver	$db					Database connection
 	* @param bool		$return_statements	True if only statements should be returned and no SQL being executed
 	*/
-	function phpbb_db_tools(&$db, $return_statements = false)
+	function phpbb_db_tools(phpbb_db_driver $db, $return_statements = false)
 	{
 		$this->db = $db;
 		$this->return_statements = $return_statements;
@@ -348,6 +346,17 @@ class phpbb_db_tools
 	}
 
 	/**
+	* Setter for {@link $return_statements return_statements}.
+	*
+	* @param bool $return_statements True if SQL should not be executed but returned as strings
+	* @return null
+	*/
+	public function set_return_statements($return_statements)
+	{
+		$this->return_statements = $return_statements;
+	}
+
+	/**
 	* Gets a list of tables in the database.
 	*
 	* @return array		Array of table names  (all lower case)
@@ -676,6 +685,8 @@ class phpbb_db_tools
 	* Handle passed database update array.
 	* Expected structure...
 	* Key being one of the following
+	*	drop_tables: Drop tables
+	*	add_tables: Add tables
 	*	change_columns: Column changes (only type, not name)
 	*	add_columns: Add columns to a table
 	*	drop_keys: Dropping keys
@@ -1504,7 +1515,7 @@ class phpbb_db_tools
 			$column_type = $this->dbms_type_map[$this->sql_layer][$column_data[0]];
 		}
 
-		// Adjust default value if db-dependant specified
+		// Adjust default value if db-dependent specified
 		if (is_array($column_data[1]))
 		{
 			$column_data[1] = (isset($column_data[1][$this->sql_layer])) ? $column_data[1][$this->sql_layer] : $column_data[1]['default'];
@@ -2473,5 +2484,3 @@ class phpbb_db_tools
 		return $this->_sql_run_sql($statements);
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/dbal.php b/phpBB/includes/db/driver/driver.php
index 9cc337955b..8dda94bc2c 100644
--- a/phpBB/includes/db/dbal.php
+++ b/phpBB/includes/db/driver/driver.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -20,7 +19,7 @@ if (!defined('IN_PHPBB'))
 * Database Abstraction Layer
 * @package dbal
 */
-class dbal
+class phpbb_db_driver
 {
 	var $db_connect_id;
 	var $query_result;
@@ -73,17 +72,17 @@ class dbal
 	/**
 	* Constructor
 	*/
-	function dbal()
+	function __construct()
 	{
 		$this->num_queries = array(
-			'cached'		=> 0,
-			'normal'		=> 0,
-			'total'			=> 0,
+			'cached'	=> 0,
+			'normal'	=> 0,
+			'total'		=> 0,
 		);
 
 		// Fill default sql layer based on the class being called.
 		// This can be changed by the specified layer itself later if needed.
-		$this->sql_layer = substr(get_class($this), 5);
+		$this->sql_layer = substr(get_class($this), strlen('phpbb_db_driver_'));
 
 		// Do not change this please! This variable is used to easy the use of it - and is hardcoded.
 		$this->any_char = chr(0) . '%';
@@ -207,7 +206,7 @@ class dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -257,7 +256,7 @@ class dbal
 				$this->sql_rowseek($rownum, $query_id);
 			}
 
-			if (!is_object($query_id) && isset($cache->sql_rowset[$query_id]))
+			if ($cache && !is_object($query_id) && $cache->sql_exists($query_id))
 			{
 				return $cache->sql_fetchfield($query_id, $field);
 			}
@@ -285,6 +284,37 @@ class dbal
 	}
 
 	/**
+	* Build a case expression
+	*
+	* Note: The two statements action_true and action_false must have the same data type (int, vchar, ...) in the database!
+	*
+	* @param	string	$condition		The condition which must be true, to use action_true rather then action_else
+	* @param	string	$action_true	SQL expression that is used, if the condition is true
+	* @param	string	$action_else	SQL expression that is used, if the condition is false, optional
+	* @return	string			CASE expression including the condition and statements
+	*/
+	public function sql_case($condition, $action_true, $action_false = false)
+	{
+		$sql_case = 'CASE WHEN ' . $condition;
+		$sql_case .= ' THEN ' . $action_true;
+		$sql_case .= ($action_false !== false) ? ' ELSE ' . $action_false : '';
+		$sql_case .= ' END';
+		return $sql_case;
+	}
+
+	/**
+	* Build a concatenated expression
+	*
+	* @param	string	$expr1		Base SQL expression where we append the second one
+	* @param	string	$expr2		SQL expression that is appended to the first expression
+	* @return	string		Concatenated string
+	*/
+	public function sql_concatenate($expr1, $expr2)
+	{
+		return $expr1 . ' || ' . $expr2;
+	}
+
+	/**
 	* Returns whether results of a query need to be buffered to run a transaction while iterating over them.
 	*
 	* @return bool Whether buffering is required.
@@ -501,6 +531,28 @@ class dbal
 	}
 
 	/**
+	* Returns SQL string to cast a string expression to an int.
+	*
+	* @param  string $expression An expression evaluating to string
+	* @return string             Expression returning an int
+	*/
+	function cast_expr_to_bigint($expression)
+	{
+		return $expression;
+	}
+
+	/**
+	* Returns SQL string to cast an integer expression to a string.
+	*
+	* @param  string $expression An expression evaluating to int
+	* @return string             Expression returning a string
+	*/
+	function cast_expr_to_string($expression)
+	{
+		return $expression;
+	}
+
+	/**
 	* Run LOWER() on DB column of type text (i.e. neither varchar nor char).
 	*
 	* @param string $column_name	The column name to use
@@ -714,8 +766,8 @@ class dbal
 
 			// Show complete SQL error and path to administrators only
 			// Additionally show complete error on installation or if extended debug mode is enabled
-			// The DEBUG_EXTRA constant is for development only!
-			if ((isset($auth) && $auth->acl_get('a_')) || defined('IN_INSTALL') || defined('DEBUG_EXTRA'))
+			// The DEBUG constant is for development only!
+			if ((isset($auth) && $auth->acl_get('a_')) || defined('IN_INSTALL') || defined('DEBUG'))
 			{
 				$message .= ($sql) ? '<br /><br />SQL<br /><br />' . htmlspecialchars($sql) : '';
 			}
@@ -770,9 +822,10 @@ class dbal
 	*/
 	function sql_report($mode, $query = '')
 	{
-		global $cache, $starttime, $phpbb_root_path, $user;
+		global $cache, $starttime, $phpbb_root_path, $phpbb_admin_path, $user;
+		global $request;
 
-		if (empty($_REQUEST['explain']))
+		if (is_object($request) && !$request->variable('explain', false))
 		{
 			return false;
 		}
@@ -794,14 +847,12 @@ class dbal
 				$mtime = explode(' ', microtime());
 				$totaltime = $mtime[0] + $mtime[1] - $starttime;
 
-				echo '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
-					<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr">
+				echo '<!DOCTYPE html>
+					<html dir="ltr">
 					<head>
-						<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
-						<meta http-equiv="Content-Style-Type" content="text/css" />
-						<meta http-equiv="imagetoolbar" content="no" />
+						<meta charset="utf-8">
 						<title>SQL Report</title>
-						<link href="' . $phpbb_root_path . 'adm/style/admin.css" rel="stylesheet" type="text/css" media="screen" />
+						<link href="' . htmlspecialchars($phpbb_admin_path) . 'style/admin.css" rel="stylesheet" type="text/css" media="screen" />
 					</head>
 					<body id="errorpage">
 					<div id="wrap">
@@ -991,10 +1042,3 @@ class dbal
 		return $rows_total;
 	}
 }
-
-/**
-* This variable holds the class name to use later
-*/
-$sql_db = (!empty($dbms)) ? 'dbal_' . basename($dbms) : 'dbal';
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/firebird.php b/phpBB/includes/db/driver/firebird.php
index 7072c58ac0..787c28b812 100644
--- a/phpBB/includes/db/firebird.php
+++ b/phpBB/includes/db/driver/firebird.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,14 +15,12 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * Firebird/Interbase Database Abstraction Layer
 * Minimum Requirement is Firebird 2.1
 * @package dbal
 */
-class dbal_firebird extends dbal
+class phpbb_db_driver_firebird extends phpbb_db_driver
 {
 	var $last_query_text = '';
 	var $service_handle = false;
@@ -151,13 +148,13 @@ class dbal_firebird extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
 			$this->last_query_text = $query;
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -252,7 +249,7 @@ class dbal_firebird extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
@@ -270,17 +267,17 @@ class dbal_firebird extends dbal
 					}
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -333,7 +330,7 @@ class dbal_firebird extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -399,7 +396,7 @@ class dbal_firebird extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -450,6 +447,23 @@ class dbal_firebird extends dbal
 	}
 
 	/**
+	* @inheritdoc
+	*/
+	function cast_expr_to_bigint($expression)
+	{
+		// Precision must be from 1 to 18
+		return 'CAST(' . $expression . ' as DECIMAL(18, 0))';
+	}
+
+	/**
+	* @inheritdoc
+	*/
+	function cast_expr_to_string($expression)
+	{
+		return 'CAST(' . $expression . ' as VARCHAR(255))';
+	}
+
+	/**
 	* return sql error array
 	* @access private
 	*/
@@ -522,5 +536,3 @@ class dbal_firebird extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/mssql.php b/phpBB/includes/db/driver/mssql.php
index 2dd95c2508..89c2c2351b 100644
--- a/phpBB/includes/db/mssql.php
+++ b/phpBB/includes/db/driver/mssql.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,14 +15,12 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * MSSQL Database Abstraction Layer
 * Minimum Requirement is MSSQL 2000+
 * @package dbal
 */
-class dbal_mssql extends dbal
+class phpbb_db_driver_mssql extends phpbb_db_driver
 {
 	var $connect_error = '';
 
@@ -49,14 +46,7 @@ class dbal_mssql extends dbal
 		@ini_set('mssql.textlimit', 2147483647);
 		@ini_set('mssql.textsize', 2147483647);
 
-		if (version_compare(PHP_VERSION, '5.1.0', '>=') || (version_compare(PHP_VERSION, '5.0.0-dev', '<=') && version_compare(PHP_VERSION, '4.4.1', '>=')))
-		{
-			$this->db_connect_id = ($this->persistency) ? @mssql_pconnect($this->server, $this->user, $sqlpassword, $new_link) : @mssql_connect($this->server, $this->user, $sqlpassword, $new_link);
-		}
-		else
-		{
-			$this->db_connect_id = ($this->persistency) ? @mssql_pconnect($this->server, $this->user, $sqlpassword) : @mssql_connect($this->server, $this->user, $sqlpassword);
-		}
+		$this->db_connect_id = ($this->persistency) ? @mssql_pconnect($this->server, $this->user, $sqlpassword, $new_link) : @mssql_connect($this->server, $this->user, $sqlpassword, $new_link);
 
 		if ($this->db_connect_id && $this->dbname != '')
 		{
@@ -108,6 +98,14 @@ class dbal_mssql extends dbal
 	}
 
 	/**
+	* {@inheritDoc}
+	*/
+	public function sql_concatenate($expr1, $expr2)
+	{
+		return $expr1 . ' + ' . $expr2;
+	}
+
+	/**
 	* SQL Transaction
 	* @access private
 	*/
@@ -147,12 +145,12 @@ class dbal_mssql extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -162,22 +160,22 @@ class dbal_mssql extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -242,7 +240,7 @@ class dbal_mssql extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -279,7 +277,7 @@ class dbal_mssql extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -318,7 +316,7 @@ class dbal_mssql extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -472,5 +470,3 @@ class dbal_mssql extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/mssql_odbc.php b/phpBB/includes/db/driver/mssql_odbc.php
index 04501cce8b..f7834443eb 100644
--- a/phpBB/includes/db/mssql_odbc.php
+++ b/phpBB/includes/db/driver/mssql_odbc.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,8 +15,6 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * Unified ODBC functions
 * Unified ODBC functions support any database having ODBC driver, for example Adabas D, IBM DB2, iODBC, Solid, Sybase SQL Anywhere...
@@ -29,7 +26,7 @@ include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
 *
 * @package dbal
 */
-class dbal_mssql_odbc extends dbal
+class phpbb_db_driver_mssql_odbc extends phpbb_db_driver
 {
 	var $last_query_text = '';
 	var $connect_error = '';
@@ -129,6 +126,14 @@ class dbal_mssql_odbc extends dbal
 	}
 
 	/**
+	* {@inheritDoc}
+	*/
+	public function sql_concatenate($expr1, $expr2)
+	{
+		return $expr1 . ' + ' . $expr2;
+	}
+
+	/**
 	* SQL Transaction
 	* @access private
 	*/
@@ -168,13 +173,13 @@ class dbal_mssql_odbc extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
 			$this->last_query_text = $query;
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -184,22 +189,22 @@ class dbal_mssql_odbc extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -265,7 +270,7 @@ class dbal_mssql_odbc extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -306,7 +311,7 @@ class dbal_mssql_odbc extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -418,5 +423,3 @@ class dbal_mssql_odbc extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/mssqlnative.php b/phpBB/includes/db/driver/mssqlnative.php
index b91372ac61..656cbd2437 100644
--- a/phpBB/includes/db/mssqlnative.php
+++ b/phpBB/includes/db/driver/mssqlnative.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2010 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 * This is the MS SQL Server Native database abstraction layer.
 * PHP mssql native driver required.
@@ -20,8 +19,6 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
  * Prior to version 1.1 the SQL Server Native PHP driver didn't support sqlsrv_num_rows, or cursor based seeking so we recall all rows into an array
  * and maintain our own cursor index into that array.
@@ -194,7 +191,7 @@ class result_mssqlnative
 /**
 * @package dbal
 */
-class dbal_mssqlnative extends dbal
+class phpbb_db_driver_mssqlnative extends phpbb_db_driver
 {
 	var $m_insert_id = NULL;
 	var $last_query_text = '';
@@ -262,6 +259,14 @@ class dbal_mssqlnative extends dbal
 	/**
 	* {@inheritDoc}
 	*/
+	public function sql_concatenate($expr1, $expr2)
+	{
+		return $expr1 . ' + ' . $expr2;
+	}
+
+	/**
+	* {@inheritDoc}
+	*/
 	function sql_buffer_nested_transactions()
 	{
 		return true;
@@ -306,13 +311,13 @@ class dbal_mssqlnative extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
 			$this->last_query_text = $query;
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -324,22 +329,22 @@ class dbal_mssqlnative extends dbal
 				// reset options for next query
 				$this->query_options = array();
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -412,7 +417,7 @@ class dbal_mssqlnative extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -472,7 +477,7 @@ class dbal_mssqlnative extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -648,5 +653,3 @@ class dbal_mssqlnative extends dbal
 		$this->query_options = $options;
 	}
 }
-
-?>
diff --git a/phpBB/includes/db/mysql.php b/phpBB/includes/db/driver/mysql.php
index 252cb20bd4..9de7283a42 100644
--- a/phpBB/includes/db/mysql.php
+++ b/phpBB/includes/db/driver/mysql.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,8 +15,6 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * MySQL4 Database Abstraction Layer
 * Compatible with:
@@ -27,7 +24,7 @@ include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
 * MySQL 5.0+
 * @package dbal
 */
-class dbal_mysql extends dbal
+class phpbb_db_driver_mysql extends phpbb_db_driver
 {
 	var $multi_insert = true;
 	var $connect_error = '';
@@ -139,6 +136,14 @@ class dbal_mysql extends dbal
 	}
 
 	/**
+	* {@inheritDoc}
+	*/
+	public function sql_concatenate($expr1, $expr2)
+	{
+		return 'CONCAT(' . $expr1 . ', ' . $expr2 . ')';
+	}
+
+	/**
 	* SQL Transaction
 	* @access private
 	*/
@@ -178,12 +183,12 @@ class dbal_mysql extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -193,22 +198,22 @@ class dbal_mysql extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -260,7 +265,7 @@ class dbal_mysql extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -281,7 +286,7 @@ class dbal_mysql extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -309,7 +314,7 @@ class dbal_mysql extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -587,5 +592,3 @@ class dbal_mysql extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/mysqli.php b/phpBB/includes/db/driver/mysqli.php
index 69f1d26a40..7448bf1670 100644
--- a/phpBB/includes/db/mysqli.php
+++ b/phpBB/includes/db/driver/mysqli.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,15 +15,13 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * MySQLi Database Abstraction Layer
 * mysqli-extension has to be compiled with:
 * MySQL 4.1+ or MySQL 5.0+
 * @package dbal
 */
-class dbal_mysqli extends dbal
+class phpbb_db_driver_mysqli extends phpbb_db_driver
 {
 	var $multi_insert = true;
 	var $connect_error = '';
@@ -131,6 +128,14 @@ class dbal_mysqli extends dbal
 	}
 
 	/**
+	* {@inheritDoc}
+	*/
+	public function sql_concatenate($expr1, $expr2)
+	{
+		return 'CONCAT(' . $expr1 . ', ' . $expr2 . ')';
+	}
+
+	/**
 	* SQL Transaction
 	* @access private
 	*/
@@ -174,12 +179,12 @@ class dbal_mysqli extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -189,17 +194,17 @@ class dbal_mysqli extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -251,7 +256,7 @@ class dbal_mysqli extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (!is_object($query_id) && isset($cache->sql_rowset[$query_id]))
+		if ($cache && !is_object($query_id) && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -278,7 +283,7 @@ class dbal_mysqli extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (!is_object($query_id) && isset($cache->sql_rowset[$query_id]))
+		if ($cache && !is_object($query_id) && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -306,7 +311,7 @@ class dbal_mysqli extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (!is_object($query_id) && isset($cache->sql_rowset[$query_id]))
+		if ($cache && !is_object($query_id) && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -577,5 +582,3 @@ class dbal_mysqli extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/oracle.php b/phpBB/includes/db/driver/oracle.php
index 4a7a4ecc8c..e21e07055d 100644
--- a/phpBB/includes/db/oracle.php
+++ b/phpBB/includes/db/driver/oracle.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,13 +15,11 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * Oracle Database Abstraction Layer
 * @package dbal
 */
-class dbal_oracle extends dbal
+class phpbb_db_driver_oracle extends phpbb_db_driver
 {
 	var $last_query_text = '';
 	var $connect_error = '';
@@ -264,13 +261,13 @@ class dbal_oracle extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
 			$this->last_query_text = $query;
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -441,22 +438,22 @@ class dbal_oracle extends dbal
 					}
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -501,7 +498,7 @@ class dbal_oracle extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -553,7 +550,7 @@ class dbal_oracle extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -622,7 +619,7 @@ class dbal_oracle extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -804,5 +801,3 @@ class dbal_oracle extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/postgres.php b/phpBB/includes/db/driver/postgres.php
index bb116e0763..14854d179d 100644
--- a/phpBB/includes/db/postgres.php
+++ b/phpBB/includes/db/driver/postgres.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,19 +15,12 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
-if (!class_exists('phpbb_error_collector'))
-{
-	include($phpbb_root_path . 'includes/error_collector.' . $phpEx);
-}
-
 /**
 * PostgreSQL Database Abstraction Layer
 * Minimum Requirement is Version 7.3+
 * @package dbal
 */
-class dbal_postgres extends dbal
+class phpbb_db_driver_postgres extends phpbb_db_driver
 {
 	var $last_query_text = '';
 	var $connect_error = '';
@@ -195,13 +187,13 @@ class dbal_postgres extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
 			$this->last_query_text = $query;
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -211,22 +203,22 @@ class dbal_postgres extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -286,7 +278,7 @@ class dbal_postgres extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -307,7 +299,7 @@ class dbal_postgres extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -356,7 +348,7 @@ class dbal_postgres extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -389,6 +381,22 @@ class dbal_postgres extends dbal
 	}
 
 	/**
+	* @inheritdoc
+	*/
+	function cast_expr_to_bigint($expression)
+	{
+		return 'CAST(' . $expression . ' as DECIMAL(255, 0))';
+	}
+
+	/**
+	* @inheritdoc
+	*/
+	function cast_expr_to_string($expression)
+	{
+		return 'CAST(' . $expression . ' as VARCHAR(255))';
+	}
+
+	/**
 	* return sql error array
 	* @access private
 	*/
@@ -481,5 +489,3 @@ class dbal_postgres extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/sqlite.php b/phpBB/includes/db/driver/sqlite.php
index 557b057cce..7188f0daa2 100644
--- a/phpBB/includes/db/sqlite.php
+++ b/phpBB/includes/db/driver/sqlite.php
@@ -2,9 +2,8 @@
 /**
 *
 * @package dbal
-* @version $Id$
 * @copyright (c) 2005 phpBB Group
-* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 *
 */
 
@@ -16,14 +15,12 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-include_once($phpbb_root_path . 'includes/db/dbal.' . $phpEx);
-
 /**
 * Sqlite Database Abstraction Layer
 * Minimum Requirement: 2.8.2+
 * @package dbal
 */
-class dbal_sqlite extends dbal
+class phpbb_db_driver_sqlite extends phpbb_db_driver
 {
 	var $connect_error = '';
 
@@ -132,12 +129,12 @@ class dbal_sqlite extends dbal
 			global $cache;
 
 			// EXPLAIN only in extra debug mode
-			if (defined('DEBUG_EXTRA'))
+			if (defined('DEBUG'))
 			{
 				$this->sql_report('start', $query);
 			}
 
-			$this->query_result = ($cache_ttl && method_exists($cache, 'sql_load')) ? $cache->sql_load($query) : false;
+			$this->query_result = ($cache && $cache_ttl) ? $cache->sql_load($query) : false;
 			$this->sql_add_num_queries($this->query_result);
 
 			if ($this->query_result === false)
@@ -147,22 +144,22 @@ class dbal_sqlite extends dbal
 					$this->sql_error($query);
 				}
 
-				if (defined('DEBUG_EXTRA'))
+				if (defined('DEBUG'))
 				{
 					$this->sql_report('stop', $query);
 				}
 
-				if ($cache_ttl && method_exists($cache, 'sql_save'))
+				if ($cache && $cache_ttl)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
-					$cache->sql_save($query, $this->query_result, $cache_ttl);
+					$this->query_result = $cache->sql_save($this, $query, $this->query_result, $cache_ttl);
 				}
 				else if (strpos($query, 'SELECT') === 0 && $this->query_result)
 				{
 					$this->open_queries[(int) $this->query_result] = $this->query_result;
 				}
 			}
-			else if (defined('DEBUG_EXTRA'))
+			else if (defined('DEBUG'))
 			{
 				$this->sql_report('fromcache', $query);
 			}
@@ -213,7 +210,7 @@ class dbal_sqlite extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_fetchrow($query_id);
 		}
@@ -234,7 +231,7 @@ class dbal_sqlite extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_rowseek($rownum, $query_id);
 		}
@@ -262,7 +259,7 @@ class dbal_sqlite extends dbal
 			$query_id = $this->query_result;
 		}
 
-		if (isset($cache->sql_rowset[$query_id]))
+		if ($cache && $cache->sql_exists($query_id))
 		{
 			return $cache->sql_freeresult($query_id);
 		}
@@ -366,5 +363,3 @@ class dbal_sqlite extends dbal
 		}
 	}
 }
-
-?>
-\ No newline at end of file
diff --git a/phpBB/includes/db/migration/exception.php b/phpBB/includes/db/migration/exception.php
new file mode 100644
index 0000000000..e84330dd71
--- /dev/null
+++ b/phpBB/includes/db/migration/exception.php
@@ -0,0 +1,79 @@
+<?php
+/**
+*
+* @package db
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* The migrator is responsible for applying new migrations in the correct order.
+*
+* @package db
+*/
+class phpbb_db_migration_exception extends \Exception
+{
+	/**
+	* Extra parameters sent to exception to aid in debugging
+	* @var array
+	*/
+	protected $parameters;
+
+	/**
+	* Throw an exception.
+	*
+	* First argument is the error message.
+	* Additional arguments will be output with the error message.
+	*/
+	public function __construct()
+	{
+		$parameters = func_get_args();
+		$message = array_shift($parameters);
+		parent::__construct($message);
+
+		$this->parameters = $parameters;
+	}
+
+	/**
+	* Output the error as a string
+	*
+	* @return string
+	*/
+	public function __toString()
+	{
+		return $this->message . ': ' . var_export($this->parameters, true);
+	}
+
+	/**
+	* Get the parameters
+	*
+	* @return array
+	*/
+	public function getParameters()
+	{
+		return $this->parameters;
+	}
+
+	/**
+	* Get localised message (with $user->lang()) 
+	* 
+	* @param phpbb_user $user
+	* @return string
+	*/
+	public function getLocalisedMessage(phpbb_user $user)
+	{
+		$parameters = $this->getParameters();
+		array_unshift($parameters, $this->getMessage());
+
+		return call_user_func_array(array($user, 'lang'), $parameters);
+	}
+}
diff --git a/phpBB/includes/db/migration/migration.php b/phpBB/includes/db/migration/migration.php
new file mode 100644
index 0000000000..5f14a6953c
--- /dev/null
+++ b/phpBB/includes/db/migration/migration.php
@@ -0,0 +1,190 @@
+<?php
+/**
+*
+* @package db
+* @copyright (c) 2011 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* Abstract base class for database migrations
+*
+* Each migration consists of a set of schema and data changes to be implemented
+* in a subclass. This class provides various utility methods to simplify editing
+* a phpBB.
+*
+* @package db
+*/
+abstract class phpbb_db_migration
+{
+	/** @var phpbb_config */
+	protected $config;
+
+	/** @var phpbb_db_driver */
+	protected $db;
+
+	/** @var phpbb_db_tools */
+	protected $db_tools;
+
+	/** @var string */
+	protected $table_prefix;
+
+	/** @var string */
+	protected $phpbb_root_path;
+
+	/** @var string */
+	protected $php_ext;
+
+	/** @var array Errors, if any occured */
+	protected $errors;
+
+	/** @var array List of queries executed through $this->sql_query() */
+	protected $queries = array();
+
+	/**
+	* Constructor
+	*
+	* @param phpbb_config $config
+	* @param phpbb_db_driver $db
+	* @param phpbb_db_tools $db_tools
+	* @param string $phpbb_root_path
+	* @param string $php_ext
+	* @param string $table_prefix
+	*/
+	public function __construct(phpbb_config $config, phpbb_db_driver $db, phpbb_db_tools $db_tools, $phpbb_root_path, $php_ext, $table_prefix)
+	{
+		$this->config = $config;
+		$this->db = $db;
+		$this->db_tools = $db_tools;
+		$this->table_prefix = $table_prefix;
+
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->php_ext = $php_ext;
+
+		$this->errors = array();
+	}
+
+	/**
+	* Defines other migrations to be applied first
+	*
+	* @return array An array of migration class names
+	*/
+	static public function depends_on()
+	{
+		return array();
+	}
+
+	/**
+	* Allows you to check if the migration is effectively installed (entirely optional)
+	*
+	* This is checked when a migration is installed. If true is returned, the migration will be set as
+	* installed without performing the database changes.
+	* This function is intended to help moving to migrations from a previous database updater, where some
+	* migrations may have been installed already even though they are not yet listed in the migrations table.
+	*
+	* @return bool True if this migration is installed, False if this migration is not installed (checked on install)
+	*/
+	public function effectively_installed()
+	{
+		return false;
+	}
+
+	/**
+	* Updates the database schema by providing a set of change instructions
+	*
+	* @return array Array of schema changes (compatible with db_tools->perform_schema_changes())
+	*/
+	public function update_schema()
+	{
+		return array();
+	}
+
+	/**
+	* Reverts the database schema by providing a set of change instructions
+	*
+	* @return array Array of schema changes (compatible with db_tools->perform_schema_changes())
+	*/
+	public function revert_schema()
+	{
+		return array();
+	}
+
+	/**
+	* Updates data by returning a list of instructions to be executed
+	*
+	* @return array Array of data update instructions
+	*/
+	public function update_data()
+	{
+		return array();
+	}
+
+	/**
+	* Reverts data by returning a list of instructions to be executed
+	*
+	* @return array Array of data instructions that will be performed on revert
+	* 	NOTE: calls to tools (such as config.add) are automatically reverted when
+	* 		possible, so you should not attempt to revert those, this is mostly for
+	* 		otherwise unrevertable calls (custom functions for example)
+	*/
+	public function revert_data()
+	{
+		return array();
+	}
+
+	/**
+	* Wrapper for running queries to generate user feedback on updates
+	*
+	* @param string $sql SQL query to run on the database
+	* @return mixed Query result from db->sql_query()
+	*/
+	protected function sql_query($sql)
+	{
+		$this->queries[] = $sql;
+
+		$this->db->sql_return_on_error(true);
+
+		if ($sql === 'begin')
+		{
+			$result = $this->db->sql_transaction('begin');
+		}
+		else if ($sql === 'commit')
+		{
+			$result = $this->db->sql_transaction('commit');
+		}
+		else
+		{
+			$result = $this->db->sql_query($sql);
+			if ($this->db->sql_error_triggered)
+			{
+				$this->errors[] = array(
+					'sql'	=> $this->db->sql_error_sql,
+					'code'	=> $this->db->sql_error_returned,
+				);
+			}
+		}
+
+		$this->db->sql_return_on_error(false);
+
+		return $result;
+	}
+
+	/**
+	* Get the list of queries run
+	*
+	* @return array
+	*/
+	public function get_queries()
+	{
+		return $this->queries;
+	}
+}
diff --git a/phpBB/includes/db/migration/tool/config.php b/phpBB/includes/db/migration/tool/config.php
new file mode 100644
index 0000000000..458a25fb66
--- /dev/null
+++ b/phpBB/includes/db/migration/tool/config.php
@@ -0,0 +1,150 @@
+<?php
+/**
+*
+* @package migration
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* Migration config tool
+*
+* @package db
+*/
+class phpbb_db_migration_tool_config implements phpbb_db_migration_tool_interface
+{
+	/** @var phpbb_config */
+	protected $config;
+
+	/**
+	* Constructor
+	*
+	* @param phpbb_config $config
+	*/
+	public function __construct(phpbb_config $config)
+	{
+		$this->config = $config;
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function get_name()
+	{
+		return 'config';
+	}
+
+	/**
+	* Add a config setting.
+	*
+	* @param string $config_name The name of the config setting
+	* 	you would like to add
+	* @param mixed $config_value The value of the config setting
+	* @param bool $is_dynamic True if it is dynamic (changes very often)
+	* 	and should not be stored in the cache, false if not.
+	* @return null
+	*/
+	public function add($config_name, $config_value, $is_dynamic = false)
+	{
+		if (isset($this->config[$config_name]))
+		{
+			throw new phpbb_db_migration_exception('CONFIG_ALREADY_EXIST', $config_name);
+		}
+
+		$this->config->set($config_name, $config_value, !$is_dynamic);
+	}
+
+	/**
+	* Update an existing config setting.
+	*
+	* @param string $config_name The name of the config setting you would
+	* 	like to update
+	* @param mixed $config_value The value of the config setting
+	* @return null
+	*/
+	public function update($config_name, $config_value)
+	{
+		if (!isset($this->config[$config_name]))
+		{
+			throw new phpbb_db_migration_exception('CONFIG_NOT_EXIST', $config_name);
+		}
+
+		$this->config->set($config_name, $config_value);
+	}
+
+	/**
+	* Update a config setting if the first argument equal to the
+	* current config value
+	*
+	* @param string $compare If equal to the current config value, will be
+	* 	updated to the new config value, otherwise not
+	* @param string $config_name The name of the config setting you would
+	* 	like to update
+	* @param mixed $config_value The value of the config setting
+	* @return null
+	*/
+	public function update_if_equals($compare, $config_name, $config_value)
+	{
+		if (!isset($this->config[$config_name]))
+		{
+			throw new phpbb_db_migration_exception('CONFIG_NOT_EXIST', $config_name);
+		}
+
+		$this->config->set_atomic($config_name, $compare, $config_value);
+	}
+
+	/**
+	* Remove an existing config setting.
+	*
+	* @param string $config_name The name of the config setting you would
+	* 	like to remove
+	* @return null
+	*/
+	public function remove($config_name)
+	{
+		if (!isset($this->config[$config_name]))
+		{
+			throw new phpbb_db_migration_exception('CONFIG_NOT_EXIST', $config_name);
+		}
+
+		$this->config->delete($config_name);
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function reverse()
+	{
+		$arguments = func_get_args();
+		$original_call = array_shift($arguments);
+
+		$call = false;
+		switch ($original_call)
+		{
+			case 'add':
+				$call = 'remove';
+			break;
+
+			case 'remove':
+				$call = 'add';
+			break;
+
+			case 'update_if_equals':
+				$call = 'update_if_equals';
+
+				// Set to the original value if the current value is what we compared to originally
+				$arguments = array(
+					$arguments[2],
+					$arguments[1],
+					$arguments[0],
+				);
+			break;
+		}
+
+		if ($call)
+		{
+			return call_user_func_array(array(&$this, $call), $arguments);
+		}
+	}
+}
diff --git a/phpBB/includes/db/migration/tool/interface.php b/phpBB/includes/db/migration/tool/interface.php
new file mode 100644
index 0000000000..ced53b2023
--- /dev/null
+++ b/phpBB/includes/db/migration/tool/interface.php
@@ -0,0 +1,33 @@
+<?php
+/**
+*
+* @package migration
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* Migration tool interface
+*
+* @package db
+*/
+interface phpbb_db_migration_tool_interface
+{
+	/**
+	* Retrieve a short name used for commands in migrations.
+	*
+	* @return string short name
+	*/
+	public function get_name();
+
+	/**
+	* Reverse an original install action
+	*
+	* First argument is the original call to the class (e.g. add, remove)
+	* After the first argument, send the original arguments to the function in the original call
+	*
+	* @return null
+	*/
+	public function reverse();
+}
diff --git a/phpBB/includes/db/migration/tool/module.php b/phpBB/includes/db/migration/tool/module.php
new file mode 100644
index 0000000000..4d7fae2bb0
--- /dev/null
+++ b/phpBB/includes/db/migration/tool/module.php
@@ -0,0 +1,513 @@
+<?php
+/**
+*
+* @package migration
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* Migration module management tool
+*
+* @package db
+*/
+class phpbb_db_migration_tool_module implements phpbb_db_migration_tool_interface
+{
+	/** @var phpbb_cache_service */
+	protected $cache;
+
+	/** @var dbal */
+	protected $db;
+
+	/** @var phpbb_user */
+	protected $user;
+
+	/** @var string */
+	protected $phpbb_root_path;
+
+	/** @var string */
+	protected $php_ext;
+
+	/** @var string */
+	protected $modules_table;
+
+	/**
+	* Constructor
+	*
+	* @param phpbb_db_driver $db
+	* @param mixed $cache
+	* @param phpbb_user $user
+	* @param string $phpbb_root_path
+	* @param string $php_ext
+	* @param string $modules_table
+	*/
+	public function __construct(phpbb_db_driver $db, phpbb_cache_service $cache, phpbb_user $user, $phpbb_root_path, $php_ext, $modules_table)
+	{
+		$this->db = $db;
+		$this->cache = $cache;
+		$this->user = $user;
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->php_ext = $php_ext;
+		$this->modules_table = $modules_table;
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function get_name()
+	{
+		return 'module';
+	}
+
+	/**
+	* Module Exists
+	*
+	* Check if a module exists
+	*
+	* @param string $class The module class(acp|mcp|ucp)
+	* @param int|string|bool $parent The parent module_id|module_langname (0 for no parent).
+	*		Use false to ignore the parent check and check class wide.
+	* @param int|string $module The module_id|module_langname you would like to
+	* 		check for to see if it exists
+	* @return bool true/false if module exists
+	*/
+	public function exists($class, $parent, $module)
+	{
+		// the main root directory should return true
+		if (!$module)
+		{
+			return true;
+		}
+
+		$parent_sql = '';
+		if ($parent !== false)
+		{
+			// Allows '' to be sent as 0
+			$parent = $parent ?: 0;
+
+			if (!is_numeric($parent))
+			{
+				$sql = 'SELECT module_id
+					FROM ' . $this->modules_table . "
+					WHERE module_langname = '" . $this->db->sql_escape($parent) . "'
+						AND module_class = '" . $this->db->sql_escape($class) . "'";
+				$result = $this->db->sql_query($sql);
+				$module_id = $this->db->sql_fetchfield('module_id');
+				$this->db->sql_freeresult($result);
+
+				if (!$module_id)
+				{
+					return false;
+				}
+
+				$parent_sql = 'AND parent_id = ' . (int) $module_id;
+			}
+			else
+			{
+				$parent_sql = 'AND parent_id = ' . (int) $parent;
+			}
+		}
+
+		$sql = 'SELECT module_id
+			FROM ' . $this->modules_table . "
+			WHERE module_class = '" . $this->db->sql_escape($class) . "'
+				$parent_sql
+				AND " . ((is_numeric($module)) ? 'module_id = ' . (int) $module : "module_langname = '" . $this->db->sql_escape($module) . "'");
+		$result = $this->db->sql_query($sql);
+		$module_id = $this->db->sql_fetchfield('module_id');
+		$this->db->sql_freeresult($result);
+
+		if ($module_id)
+		{
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	* Module Add
+	*
+	* Add a new module
+	*
+	* @param string $class The module class(acp|mcp|ucp)
+	* @param int|string $parent The parent module_id|module_langname (0 for no parent)
+	* @param array $data an array of the data on the new module.
+	* 	This can be setup in two different ways.
+	*	1. The "manual" way.  For inserting a category or one at a time.
+	*		It will be merged with the base array shown a bit below,
+	*			but at the least requires 'module_langname' to be sent, and,
+	*			if you want to create a module (instead of just a category) you must
+	*			send module_basename and module_mode.
+	*		array(
+	*			'module_enabled'	=> 1,
+	*			'module_display'	=> 1,
+	*	   		'module_basename'	=> '',
+	*			'module_class'		=> $class,
+	*	   		'parent_id'			=> (int) $parent,
+	*			'module_langname'	=> '',
+	*	   		'module_mode'		=> '',
+	*	   		'module_auth'		=> '',
+	*		)
+	*	2. The "automatic" way.  For inserting multiple at a time based on the
+	*			specs in the info file for the module(s).  For this to work the
+	*			modules must be correctly setup in the info file.
+	*		An example follows (this would insert the settings, log, and flag
+	*			modes from the includes/acp/info/acp_asacp.php file):
+	* 		array(
+	* 			'module_basename'	=> 'asacp',
+	* 			'modes'				=> array('settings', 'log', 'flag'),
+	* 		)
+	* 		Optionally you may not send 'modes' and it will insert all of the
+	* 			modules in that info file.
+	* @param string|bool $include_path If you would like to use a custom include
+	* 	path, specify that here
+	* @return null
+	*/
+	public function add($class, $parent = 0, $data = array(), $include_path = false)
+	{
+		// Allows '' to be sent as 0
+		$parent = $parent ?: 0;
+
+		// allow sending the name as a string in $data to create a category
+		if (!is_array($data))
+		{
+			$data = array('module_langname' => $data);
+		}
+
+		if (!isset($data['module_langname']))
+		{
+			// The "automatic" way
+			$basename = (isset($data['module_basename'])) ? $data['module_basename'] : '';
+			$basename = str_replace(array('/', '\\'), '', $basename);
+			$class = str_replace(array('/', '\\'), '', $class);
+
+			$include_path = ($include_path === false) ? $this->phpbb_root_path . 'includes/' : $include_path;
+			$info_file = "$class/info/$basename.{$this->php_ext}";
+
+			// The manual and automatic ways both failed...
+			if (!file_exists($include_path . $info_file))
+			{
+				throw new phpbb_db_migration_exception('MODULE_INFO_FILE_NOT_EXIST', $class, $info_file);
+			}
+
+			$classname = "{$basename}_info";
+
+			if (!class_exists($classname))
+			{
+				include($include_path . $info_file);
+			}
+
+			$info = new $classname;
+			$module = $info->module();
+			unset($info);
+
+			$result = '';
+			foreach ($module['modes'] as $mode => $module_info)
+			{
+				if (!isset($data['modes']) || in_array($mode, $data['modes']))
+				{
+					$new_module = array(
+						'module_basename'	=> $basename,
+						'module_langname'	=> $module_info['title'],
+						'module_mode'		=> $mode,
+						'module_auth'		=> $module_info['auth'],
+						'module_display'	=> (isset($module_info['display'])) ? $module_info['display'] : true,
+						'before'			=> (isset($module_info['before'])) ? $module_info['before'] : false,
+						'after'				=> (isset($module_info['after'])) ? $module_info['after'] : false,
+					);
+
+					// Run the "manual" way with the data we've collected.
+					$this->add($class, $parent, $new_module);
+				}
+			}
+
+			return;
+		}
+
+		// The "manual" way
+		$module_log_name = ((isset($this->user->lang[$data['module_langname']])) ? $this->user->lang[$data['module_langname']] : $data['module_langname']);
+		add_log('admin', 'LOG_MODULE_ADD', $module_log_name);
+
+		if (!is_numeric($parent))
+		{
+			$sql = 'SELECT module_id
+				FROM ' . $this->modules_table . "
+				WHERE module_langname = '" . $this->db->sql_escape($parent) . "'
+					AND module_class = '" . $this->db->sql_escape($class) . "'";
+			$result = $this->db->sql_query($sql);
+			$module_id = $this->db->sql_fetchfield('module_id');
+			$this->db->sql_freeresult($result);
+
+			if (!$module_id)
+			{
+				throw new phpbb_db_migration_exception('MODULE_NOT_EXIST', $parent);
+			}
+
+			$parent = $data['parent_id'] = $module_id;
+		}
+		else if (!$this->exists($class, false, $parent))
+		{
+			throw new phpbb_db_migration_exception('MODULE_NOT_EXIST', $parent);
+		}
+
+		if ($this->exists($class, $parent, $data['module_langname']))
+		{
+			throw new phpbb_db_migration_exception('MODULE_ALREADY_EXIST', $data['module_langname']);
+		}
+
+		if (!class_exists('acp_modules'))
+		{
+			include($this->phpbb_root_path . 'includes/acp/acp_modules.' . $this->php_ext);
+			$this->user->add_lang('acp/modules');
+		}
+		$acp_modules = new acp_modules();
+
+		$module_data = array(
+			'module_enabled'	=> (isset($data['module_enabled'])) ? $data['module_enabled'] : 1,
+			'module_display'	=> (isset($data['module_display'])) ? $data['module_display'] : 1,
+			'module_basename'	=> (isset($data['module_basename'])) ? $data['module_basename'] : '',
+			'module_class'		=> $class,
+			'parent_id'			=> (int) $parent,
+			'module_langname'	=> (isset($data['module_langname'])) ? $data['module_langname'] : '',
+			'module_mode'		=> (isset($data['module_mode'])) ? $data['module_mode'] : '',
+			'module_auth'		=> (isset($data['module_auth'])) ? $data['module_auth'] : '',
+		);
+		$result = $acp_modules->update_module_data($module_data, true);
+
+		// update_module_data can either return a string or an empty array...
+		if (is_string($result))
+		{
+			// Error
+			throw new phpbb_db_migration_exception('MODULE_ERROR', $result);
+		}
+		else
+		{
+			// Success
+
+			// Move the module if requested above/below an existing one
+			if (isset($data['before']) && $data['before'])
+			{
+				$sql = 'SELECT left_id
+					FROM ' . $this->modules_table . "
+					WHERE module_class = '" . $this->db->sql_escape($class) . "'
+						AND parent_id = " . (int) $parent . "
+						AND module_langname = '" . $this->db->sql_escape($data['before']) . "'";
+				$this->db->sql_query($sql);
+				$to_left = (int) $this->db->sql_fetchfield('left_id');
+
+				$sql = 'UPDATE ' . $this->modules_table . "
+					SET left_id = left_id + 2, right_id = right_id + 2
+					WHERE module_class = '" . $this->db->sql_escape($class) . "'
+						AND left_id >= $to_left
+						AND left_id < {$module_data['left_id']}";
+				$this->db->sql_query($sql);
+
+				$sql = 'UPDATE ' . $this->modules_table . "
+					SET left_id = $to_left, right_id = " . ($to_left + 1) . "
+					WHERE module_class = '" . $this->db->sql_escape($class) . "'
+						AND module_id = {$module_data['module_id']}";
+				$this->db->sql_query($sql);
+			}
+			else if (isset($data['after']) && $data['after'])
+			{
+				$sql = 'SELECT right_id
+					FROM ' . $this->modules_table . "
+					WHERE module_class = '" . $this->db->sql_escape($class) . "'
+						AND parent_id = " . (int) $parent . "
+						AND module_langname = '" . $this->db->sql_escape($data['after']) . "'";
+				$this->db->sql_query($sql);
+				$to_right = (int) $this->db->sql_fetchfield('right_id');
+
+				$sql = 'UPDATE ' . $this->modules_table . "
+					SET left_id = left_id + 2, right_id = right_id + 2
+					WHERE module_class = '" . $this->db->sql_escape($class) . "'
+						AND left_id >= $to_right
+						AND left_id < {$module_data['left_id']}";
+				$this->db->sql_query($sql);
+
+				$sql = 'UPDATE ' . $this->modules_table . '
+					SET left_id = ' . ($to_right + 1) . ', right_id = ' . ($to_right + 2) . "
+					WHERE module_class = '" . $this->db->sql_escape($class) . "'
+						AND module_id = {$module_data['module_id']}";
+				$this->db->sql_query($sql);
+			}
+		}
+
+		// Clear the Modules Cache
+		$this->cache->destroy("_modules_$class");
+	}
+
+	/**
+	* Module Remove
+	*
+	* Remove a module
+	*
+	* @param string $class The module class(acp|mcp|ucp)
+	* @param int|string|bool $parent The parent module_id|module_langname(0 for no parent).
+	* 	Use false to ignore the parent check and check class wide.
+	* @param int|string $module The module id|module_langname
+	* @param string|bool $include_path If you would like to use a custom include path,
+	* 	specify that here
+	* @return null
+	*/
+	public function remove($class, $parent = 0, $module = '', $include_path = false)
+	{
+		// Imitation of module_add's "automatic" and "manual" method so the uninstaller works from the same set of instructions for umil_auto
+		if (is_array($module))
+		{
+			if (isset($module['module_langname']))
+			{
+				// Manual Method
+				return $this->remove($class, $parent, $module['module_langname'], $include_path);
+			}
+
+			// Failed.
+			if (!isset($module['module_basename']))
+			{
+				throw new phpbb_db_migration_exception('MODULE_NOT_EXIST');
+			}
+
+			// Automatic method
+			$basename = str_replace(array('/', '\\'), '', $module['module_basename']);
+			$class = str_replace(array('/', '\\'), '', $class);
+
+			$include_path = ($include_path === false) ? $this->phpbb_root_path . 'includes/' : $include_path;
+			$info_file = "$class/info/$basename.{$this->php_ext}";
+
+			if (!file_exists($include_path . $info_file))
+			{
+				throw new phpbb_db_migration_exception('MODULE_NOT_EXIST', $info_file);
+			}
+
+			$classname = "{$basename}_info";
+
+			if (!class_exists($classname))
+			{
+				include($include_path . $info_file);
+			}
+
+			$info = new $classname;
+			$module_info = $info->module();
+			unset($info);
+
+			foreach ($module_info['modes'] as $mode => $info)
+			{
+				if (!isset($module['modes']) || in_array($mode, $module['modes']))
+				{
+					$this->remove($class, $parent, $info['title']) . '<br />';
+				}
+			}
+		}
+		else
+		{
+			if (!$this->exists($class, $parent, $module))
+			{
+				throw new phpbb_db_migration_exception('MODULE_NOT_EXIST', ((isset($this->user->lang[$module])) ? $this->user->lang[$module] : $module));
+			}
+
+			$parent_sql = '';
+			if ($parent !== false)
+			{
+				// Allows '' to be sent as 0
+				$parent = ($parent) ?: 0;
+
+				if (!is_numeric($parent))
+				{
+					$sql = 'SELECT module_id
+						FROM ' . $this->modules_table . "
+						WHERE module_langname = '" . $this->db->sql_escape($parent) . "'
+							AND module_class = '" . $this->db->sql_escape($class) . "'";
+					$result = $this->db->sql_query($sql);
+					$module_id = $this->db->sql_fetchfield('module_id');
+					$this->db->sql_freeresult($result);
+
+					// we know it exists from the module_exists check
+					$parent_sql = 'AND parent_id = ' . (int) $module_id;
+				}
+				else
+				{
+					$parent_sql = 'AND parent_id = ' . (int) $parent;
+				}
+			}
+
+			$module_ids = array();
+			if (!is_numeric($module))
+			{
+				$sql = 'SELECT module_id
+					FROM ' . $this->modules_table . "
+					WHERE module_langname = '" . $this->db->sql_escape($module) . "'
+						AND module_class = '" . $this->db->sql_escape($class) . "'
+						$parent_sql";
+				$result = $this->db->sql_query($sql);
+				while ($module_id = $this->db->sql_fetchfield('module_id'))
+				{
+					$module_ids[] = (int) $module_id;
+				}
+				$this->db->sql_freeresult($result);
+
+				$module_name = $module;
+			}
+			else
+			{
+				$module = (int) $module;
+				$sql = 'SELECT module_langname
+					FROM ' . $this->modules_table . "
+					WHERE module_id = $module
+						AND module_class = '" . $this->db->sql_escape($class) . "'
+						$parent_sql";
+				$result = $this->db->sql_query($sql);
+				$module_name = $this->db->sql_fetchfield('module_id');
+				$this->db->sql_freeresult($result);
+
+				$module_ids[] = $module;
+			}
+
+			if (!class_exists('acp_modules'))
+			{
+				include($this->phpbb_root_path . 'includes/acp/acp_modules.' . $this->php_ext);
+				$this->user->add_lang('acp/modules');
+			}
+			$acp_modules = new acp_modules();
+			$acp_modules->module_class = $class;
+
+			foreach ($module_ids as $module_id)
+			{
+				$result = $acp_modules->delete_module($module_id);
+				if (!empty($result))
+				{
+					throw new phpbb_db_migration_exception('MODULE_NOT_REMOVABLE', $module_id, $result);
+				}
+			}
+
+			$this->cache->destroy("_modules_$class");
+		}
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function reverse()
+	{
+		$arguments = func_get_args();
+		$original_call = array_shift($arguments);
+
+		$call = false;
+		switch ($original_call)
+		{
+			case 'add':
+				$call = 'remove';
+			break;
+
+			case 'remove':
+				$call = 'add';
+			break;
+		}
+
+		if ($call)
+		{
+			return call_user_func_array(array(&$this, $call), $arguments);
+		}
+	}
+}
diff --git a/phpBB/includes/db/migration/tool/permission.php b/phpBB/includes/db/migration/tool/permission.php
new file mode 100644
index 0000000000..4231fbe1dd
--- /dev/null
+++ b/phpBB/includes/db/migration/tool/permission.php
@@ -0,0 +1,622 @@
+<?php
+/**
+*
+* @package migration
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+/**
+* Migration permission management tool
+*
+* @package db
+*/
+class phpbb_db_migration_tool_permission implements phpbb_db_migration_tool_interface
+{
+	/** @var phpbb_auth */
+	protected $auth;
+
+	/** @var phpbb_cache_service */
+	protected $cache;
+
+	/** @var dbal */
+	protected $db;
+
+	/** @var string */
+	protected $phpbb_root_path;
+
+	/** @var string */
+	protected $php_ext;
+
+	/**
+	* Constructor
+	*
+	* @param phpbb_db_driver $db
+	* @param mixed $cache
+	* @param phpbb_auth $auth
+	* @param string $phpbb_root_path
+	* @param string $php_ext
+	*/
+	public function __construct(phpbb_db_driver $db, phpbb_cache_service $cache, phpbb_auth $auth, $phpbb_root_path, $php_ext)
+	{
+		$this->db = $db;
+		$this->cache = $cache;
+		$this->auth = $auth;
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->php_ext = $php_ext;
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function get_name()
+	{
+		return 'permission';
+	}
+
+	/**
+	* Permission Exists
+	*
+	* Check if a permission (auth) setting exists
+	*
+	* @param string $auth_option The name of the permission (auth) option
+	* @param bool $global True for checking a global permission setting,
+	* 	False for a local permission setting
+	* @return bool true if it exists, false if not
+	*/
+	public function exists($auth_option, $global = true)
+	{
+		if ($global)
+		{
+			$type_sql = ' AND is_global = 1';
+		}
+		else
+		{
+			$type_sql = ' AND is_local = 1';
+		}
+
+		$sql = 'SELECT auth_option_id
+			FROM ' . ACL_OPTIONS_TABLE . "
+			WHERE auth_option = '" . $this->db->sql_escape($auth_option) . "'"
+				. $type_sql;
+		$result = $this->db->sql_query($sql);
+
+		$row = $this->db->sql_fetchrow($result);
+		$this->db->sql_freeresult($result);
+
+		if ($row)
+		{
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	* Permission Add
+	*
+	* Add a permission (auth) option
+	*
+	* @param string $auth_option The name of the permission (auth) option
+	* @param bool $global True for checking a global permission setting,
+	* 	False for a local permission setting
+	* @return null
+	*/
+	public function add($auth_option, $global = true, $copy_from = false)
+	{
+		if ($this->exists($auth_option, $global))
+		{
+			throw new phpbb_db_migration_exception('PERMISSION_ALREADY_EXIST', $auth_option);
+		}
+
+		// We've added permissions, so set to true to notify the user.
+		$this->permissions_added = true;
+
+		if (!class_exists('auth_admin'))
+		{
+			include($this->phpbb_root_path . 'includes/acp/auth.' . $this->php_ext);
+		}
+		$auth_admin = new auth_admin();
+
+		// We have to add a check to see if the !$global (if global, local, and if local, global) permission already exists.  If it does, acl_add_option currently has a bug which would break the ACL system, so we are having a work-around here.
+		if ($this->exists($auth_option, !$global))
+		{
+			$sql_ary = array(
+				'is_global'	=> 1,
+				'is_local'	=> 1,
+			);
+			$sql = 'UPDATE ' . ACL_OPTIONS_TABLE . '
+				SET ' . $this->db->sql_build_array('UPDATE', $sql_ary) . "
+				WHERE auth_option = '" . $this->db->sql_escape($auth_option) . "'";
+			$this->db->sql_query($sql);
+		}
+		else
+		{
+			if ($global)
+			{
+				$auth_admin->acl_add_option(array('global' => array($auth_option)));
+			}
+			else
+			{
+				$auth_admin->acl_add_option(array('local' => array($auth_option)));
+			}
+		}
+
+		// The permission has been added, now we can copy it if needed
+		if ($copy_from && isset($auth_admin->acl_options['id'][$copy_from]))
+		{
+			$old_id = $auth_admin->acl_options['id'][$copy_from];
+			$new_id = $auth_admin->acl_options['id'][$auth_option];
+
+			$tables = array(ACL_GROUPS_TABLE, ACL_ROLES_DATA_TABLE, ACL_USERS_TABLE);
+
+			foreach ($tables as $table)
+			{
+				$sql = 'SELECT *
+					FROM ' . $table . '
+					WHERE auth_option_id = ' . $old_id;
+				$result = $this->db->sql_query($sql);
+
+				$sql_ary = array();
+				while ($row = $this->db->sql_fetchrow($result))
+				{
+					$row['auth_option_id'] = $new_id;
+					$sql_ary[] = $row;
+				}
+				$this->db->sql_freeresult($result);
+
+				if (!empty($sql_ary))
+				{
+					$this->db->sql_multi_insert($table, $sql_ary);
+				}
+			}
+
+			$auth_admin->acl_clear_prefetch();
+		}
+	}
+
+	/**
+	* Permission Remove
+	*
+	* Remove a permission (auth) option
+	*
+	* @param string $auth_option The name of the permission (auth) option
+	* @param bool $global True for checking a global permission setting,
+	* 	False for a local permission setting
+	* @return null
+	*/
+	public function remove($auth_option, $global = true)
+	{
+		if (!$this->exists($auth_option, $global))
+		{
+			throw new phpbb_db_migration_exception('PERMISSION_NOT_EXIST', $auth_option);
+		}
+
+		if ($global)
+		{
+			$type_sql = ' AND is_global = 1';
+		}
+		else
+		{
+			$type_sql = ' AND is_local = 1';
+		}
+		$sql = 'SELECT auth_option_id, is_global, is_local
+			FROM ' . ACL_OPTIONS_TABLE . "
+			WHERE auth_option = '" . $this->db->sql_escape($auth_option) . "'" .
+				$type_sql;
+		$result = $this->db->sql_query($sql);
+		$row = $this->db->sql_fetchrow($result);
+		$this->db->sql_freeresult($result);
+
+		$id = (int) $row['auth_option_id'];
+
+		// If it is a local and global permission, do not remove the row! :P
+		if ($row['is_global'] && $row['is_local'])
+		{
+			$sql = 'UPDATE ' . ACL_OPTIONS_TABLE . '
+				SET ' . (($global) ? 'is_global = 0' : 'is_local = 0') . '
+				WHERE auth_option_id = ' . $id;
+			$this->db->sql_query($sql);
+		}
+		else
+		{
+			// Delete time
+			$tables = array(ACL_GROUPS_TABLE, ACL_ROLES_DATA_TABLE, ACL_USERS_TABLE, ACL_OPTIONS_TABLE);
+			foreach ($tables as $table)
+			{
+				$this->db->sql_query('DELETE FROM ' . $table . '
+					WHERE auth_option_id = ' . $id);
+			}
+		}
+
+		// Purge the auth cache
+		$this->cache->destroy('_acl_options');
+		$this->auth->acl_clear_prefetch();
+	}
+
+	/**
+	* Add a new permission role
+	*
+	* @param string $role_name The new role name
+	* @param sting $role_type The type (u_, m_, a_)
+	* @return null
+	*/
+	public function role_add($role_name, $role_type, $role_description = '')
+	{
+		$sql = 'SELECT role_id
+			FROM ' . ACL_ROLES_TABLE . "
+			WHERE role_name = '" . $this->db->sql_escape($role_name) . "'";
+		$this->db->sql_query($sql);
+		$role_id = (int) $this->db->sql_fetchfield('role_id');
+
+		if ($role_id)
+		{
+			return;
+		}
+
+		$sql = 'SELECT MAX(role_order) AS max_role_order
+			FROM ' . ACL_ROLES_TABLE . "
+			WHERE role_type = '" . $this->db->sql_escape($role_type) . "'";
+		$this->db->sql_query($sql);
+		$role_order = (int) $this->db->sql_fetchfield('max_role_order');
+		$role_order = (!$role_order) ? 1 : $role_order + 1;
+
+		$sql_ary = array(
+			'role_name'			=> $role_name,
+			'role_description'	=> $role_description,
+			'role_type'			=> $role_type,
+			'role_order'		=> $role_order,
+		);
+
+		$sql = 'INSERT INTO ' . ACL_ROLES_TABLE . ' ' . $this->db->sql_build_array('INSERT', $sql_ary);
+		$this->db->sql_query($sql);
+	}
+
+	/**
+	* Update the name on a permission role
+	*
+	* @param string $old_role_name The old role name
+	* @param string $new_role_name The new role name
+	* @return null
+	*/
+	public function role_update($old_role_name, $new_role_name)
+	{
+		$sql = 'SELECT role_id
+			FROM ' . ACL_ROLES_TABLE . "
+			WHERE role_name = '" . $this->db->sql_escape($old_role_name) . "'";
+		$this->db->sql_query($sql);
+		$role_id = (int) $this->db->sql_fetchfield('role_id');
+
+		if (!$role_id)
+		{
+			throw new phpbb_db_migration_exception('ROLE_NOT_EXIST', $old_role_name);
+		}
+
+		$sql = 'UPDATE ' . ACL_ROLES_TABLE . "
+			SET role_name = '" . $this->db->sql_escape($new_role_name) . "'
+			WHERE role_name = '" . $this->db->sql_escape($old_role_name) . "'";
+		$this->db->sql_query($sql);
+	}
+
+	/**
+	* Remove a permission role
+	*
+	* @param string $role_name The role name to remove
+	* @return null
+	*/
+	public function role_remove($role_name)
+	{
+		$sql = 'SELECT role_id
+			FROM ' . ACL_ROLES_TABLE . "
+			WHERE role_name = '" . $this->db->sql_escape($role_name) . "'";
+		$this->db->sql_query($sql);
+		$role_id = (int) $this->db->sql_fetchfield('role_id');
+
+		if (!$role_id)
+		{
+			throw new phpbb_db_migration_exception('ROLE_NOT_EXIST', $role_name);
+		}
+
+		$sql = 'DELETE FROM ' . ACL_ROLES_DATA_TABLE . '
+			WHERE role_id = ' . $role_id;
+		$this->db->sql_query($sql);
+
+		$sql = 'DELETE FROM ' . ACL_ROLES_TABLE . '
+			WHERE role_id = ' . $role_id;
+		$this->db->sql_query($sql);
+
+		$this->auth->acl_clear_prefetch();
+	}
+
+	/**
+	* Permission Set
+	*
+	* Allows you to set permissions for a certain group/role
+	*
+	* @param string $name The name of the role/group
+	* @param string|array $auth_option The auth_option or array of
+	* 	auth_options you would like to set
+	* @param string $type The type (role|group)
+	* @param bool $has_permission True if you want to give them permission,
+	* 	false if you want to deny them permission
+	* @return null
+	*/
+	public function permission_set($name, $auth_option, $type = 'role', $has_permission = true)
+	{
+		if (!is_array($auth_option))
+		{
+			$auth_option = array($auth_option);
+		}
+
+		$new_auth = array();
+		$sql = 'SELECT auth_option_id
+			FROM ' . ACL_OPTIONS_TABLE . '
+			WHERE ' . $this->db->sql_in_set('auth_option', $auth_option);
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$new_auth[] = (int) $row['auth_option_id'];
+		}
+		$this->db->sql_freeresult($result);
+
+		if (empty($new_auth))
+		{
+			return;
+		}
+
+		$current_auth = array();
+
+		$type = (string) $type; // Prevent PHP bug.
+
+		switch ($type)
+		{
+			case 'role':
+				$sql = 'SELECT role_id
+					FROM ' . ACL_ROLES_TABLE . "
+					WHERE role_name = '" . $this->db->sql_escape($name) . "'";
+				$this->db->sql_query($sql);
+				$role_id = (int) $this->db->sql_fetchfield('role_id');
+
+				if (!$role_id)
+				{
+					throw new phpbb_db_migration_exception('ROLE_NOT_EXIST', $name);
+				}
+
+				$sql = 'SELECT auth_option_id, auth_setting
+					FROM ' . ACL_ROLES_DATA_TABLE . '
+					WHERE role_id = ' . $role_id;
+				$result = $this->db->sql_query($sql);
+				while ($row = $this->db->sql_fetchrow($result))
+				{
+					$current_auth[$row['auth_option_id']] = $row['auth_setting'];
+				}
+				$this->db->sql_freeresult($result);
+			break;
+
+			case 'group':
+				$sql = 'SELECT group_id
+					FROM ' . GROUPS_TABLE . "
+					WHERE group_name = '" . $this->db->sql_escape($name) . "'";
+				$this->db->sql_query($sql);
+				$group_id = (int) $this->db->sql_fetchfield('group_id');
+
+				if (!$group_id)
+				{
+					throw new phpbb_db_migration_exception('GROUP_NOT_EXIST', $name);
+				}
+
+				// If the group has a role set for them we will add the requested permissions to that role.
+				$sql = 'SELECT auth_role_id
+					FROM ' . ACL_GROUPS_TABLE . '
+					WHERE group_id = ' . $group_id . '
+						AND auth_role_id <> 0
+						AND forum_id = 0';
+				$this->db->sql_query($sql);
+				$role_id = (int) $this->db->sql_fetchfield('auth_role_id');
+				if ($role_id)
+				{
+					$sql = 'SELECT role_name
+						FROM ' . ACL_ROLES_TABLE . '
+						WHERE role_id = ' . $role_id;
+					$this->db->sql_query($sql);
+					$role_name = $this->db->sql_fetchfield('role_name');
+
+					return $this->set($role_name, $auth_option, 'role', $has_permission);
+				}
+
+				$sql = 'SELECT auth_option_id, auth_setting
+					FROM ' . ACL_GROUPS_TABLE . '
+					WHERE group_id = ' . $group_id;
+				$result = $this->db->sql_query($sql);
+				while ($row = $this->db->sql_fetchrow($result))
+				{
+					$current_auth[$row['auth_option_id']] = $row['auth_setting'];
+				}
+				$this->db->sql_freeresult($result);
+			break;
+		}
+
+		$sql_ary = array();
+		switch ($type)
+		{
+			case 'role':
+				foreach ($new_auth as $auth_option_id)
+				{
+					if (!isset($current_auth[$auth_option_id]))
+					{
+						$sql_ary[] = array(
+							'role_id'			=> $role_id,
+							'auth_option_id'	=> $auth_option_id,
+							'auth_setting'		=> $has_permission,
+						);
+					}
+				}
+
+				$this->db->sql_multi_insert(ACL_ROLES_DATA_TABLE, $sql_ary);
+			break;
+
+			case 'group':
+				foreach ($new_auth as $auth_option_id)
+				{
+					if (!isset($current_auth[$auth_option_id]))
+					{
+						$sql_ary[] = array(
+							'group_id'			=> $group_id,
+							'auth_option_id'	=> $auth_option_id,
+							'auth_setting'		=> $has_permission,
+						);
+					}
+				}
+
+				$this->db->sql_multi_insert(ACL_GROUPS_TABLE, $sql_ary);
+			break;
+		}
+
+		$this->auth->acl_clear_prefetch();
+	}
+
+	/**
+	* Permission Unset
+	*
+	* Allows you to unset (remove) permissions for a certain group/role
+	*
+	* @param string $name The name of the role/group
+	* @param string|array $auth_option The auth_option or array of
+	* 	auth_options you would like to set
+	* @param string $type The type (role|group)
+	* @return null
+	*/
+	public function permission_unset($name, $auth_option, $type = 'role')
+	{
+		if (!is_array($auth_option))
+		{
+			$auth_option = array($auth_option);
+		}
+
+		$to_remove = array();
+		$sql = 'SELECT auth_option_id
+			FROM ' . ACL_OPTIONS_TABLE . '
+			WHERE ' . $this->db->sql_in_set('auth_option', $auth_option);
+		$result = $this->db->sql_query($sql);
+		while ($row = $this->db->sql_fetchrow($result))
+		{
+			$to_remove[] = (int) $row['auth_option_id'];
+		}
+		$this->db->sql_freeresult($result);
+
+		if (empty($to_remove))
+		{
+			return;
+		}
+
+		$type = (string) $type; // Prevent PHP bug.
+
+		switch ($type)
+		{
+			case 'role':
+				$sql = 'SELECT role_id
+					FROM ' . ACL_ROLES_TABLE . "
+					WHERE role_name = '" . $this->db->sql_escape($name) . "'";
+				$this->db->sql_query($sql);
+				$role_id = (int) $this->db->sql_fetchfield('role_id');
+
+				if (!$role_id)
+				{
+					throw new phpbb_db_migration_exception('ROLE_NOT_EXIST', $name);
+				}
+
+				$sql = 'DELETE FROM ' . ACL_ROLES_DATA_TABLE . '
+					WHERE ' . $this->db->sql_in_set('auth_option_id', $to_remove);
+				$this->db->sql_query($sql);
+			break;
+
+			case 'group':
+				$sql = 'SELECT group_id
+					FROM ' . GROUPS_TABLE . "
+					WHERE group_name = '" . $this->db->sql_escape($name) . "'";
+				$this->db->sql_query($sql);
+				$group_id = (int) $this->db->sql_fetchfield('group_id');
+
+				if (!$group_id)
+				{
+					throw new phpbb_db_migration_exception('GROUP_NOT_EXIST', $name);
+				}
+
+				// If the group has a role set for them we will remove the requested permissions from that role.
+				$sql = 'SELECT auth_role_id
+					FROM ' . ACL_GROUPS_TABLE . '
+					WHERE group_id = ' . $group_id . '
+						AND auth_role_id <> 0';
+				$this->db->sql_query($sql);
+				$role_id = (int) $this->db->sql_fetchfield('auth_role_id');
+				if ($role_id)
+				{
+					$sql = 'SELECT role_name
+						FROM ' . ACL_ROLES_TABLE . '
+						WHERE role_id = ' . $role_id;
+					$this->db->sql_query($sql);
+					$role_name = $this->db->sql_fetchfield('role_name');
+
+					return $this->permission_unset($role_name, $auth_option, 'role');
+				}
+
+				$sql = 'DELETE FROM ' . ACL_GROUPS_TABLE . '
+					WHERE ' . $this->db->sql_in_set('auth_option_id', $to_remove);
+				$this->db->sql_query($sql);
+			break;
+		}
+
+		$this->auth->acl_clear_prefetch();
+	}
+
+	/**
+	* {@inheritdoc}
+	*/
+	public function reverse()
+	{
+		$arguments = func_get_args();
+		$original_call = array_shift($arguments);
+
+		$call = false;
+		switch ($original_call)
+		{
+			case 'add':
+				$call = 'remove';
+			break;
+
+			case 'remove':
+				$call = 'add';
+			break;
+
+			case 'permission_set':
+				$call = 'permission_unset';
+			break;
+
+			case 'permission_unset':
+				$call = 'permission_set';
+			break;
+
+			case 'role_add':
+				$call = 'role_remove';
+			break;
+
+			case 'role_remove':
+				$call = 'role_add';
+			break;
+
+			case 'role_update':
+				// Set to the original value if the current value is what we compared to originally
+				$arguments = array(
+					$arguments[1],
+					$arguments[0],
+				);
+			break;
+		}
+
+		if ($call)
+		{
+			return call_user_func_array(array(&$this, $call), $arguments);
+		}
+	}
+}
diff --git a/phpBB/includes/db/migrator.php b/phpBB/includes/db/migrator.php
new file mode 100644
index 0000000000..41d996b1e3
--- /dev/null
+++ b/phpBB/includes/db/migrator.php
@@ -0,0 +1,764 @@
+<?php
+/**
+*
+* @package db
+* @copyright (c) 2011 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* The migrator is responsible for applying new migrations in the correct order.
+*
+* @package db
+*/
+class phpbb_db_migrator
+{
+	/** @var phpbb_config */
+	protected $config;
+
+	/** @var phpbb_db_driver */
+	protected $db;
+
+	/** @var phpbb_db_tools */
+	protected $db_tools;
+
+	/** @var string */
+	protected $table_prefix;
+
+	/** @var string */
+	protected $phpbb_root_path;
+
+	/** @var string */
+	protected $php_ext;
+
+	/** @var string */
+	protected $migrations_table;
+
+	/**
+	* State of all migrations
+	*
+	* (SELECT * FROM migrations table)
+	*
+	* @var array
+	*/
+	protected $migration_state = array();
+
+	/**
+	* Array of all migrations available to be run
+	*
+	* @var array
+	*/
+	protected $migrations = array();
+
+	/**
+	* 'name' and 'class' of the last migration run
+	*
+	* @var array
+	*/
+	public $last_run_migration = false;
+
+	/**
+	* Constructor of the database migrator
+	*/
+	public function __construct(phpbb_config $config, phpbb_db_driver $db, phpbb_db_tools $db_tools, $migrations_table, $phpbb_root_path, $php_ext, $table_prefix, $tools)
+	{
+		$this->config = $config;
+		$this->db = $db;
+		$this->db_tools = $db_tools;
+
+		$this->migrations_table = $migrations_table;
+
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->php_ext = $php_ext;
+
+		$this->table_prefix = $table_prefix;
+
+		foreach ($tools as $tool)
+		{
+			$this->tools[$tool->get_name()] = $tool;
+		}
+
+		$this->load_migration_state();
+	}
+
+	/**
+	* Loads all migrations and their application state from the database.
+	*
+	* @return null
+	*/
+	public function load_migration_state()
+	{
+		$this->migration_state = array();
+
+		$sql = "SELECT *
+			FROM " . $this->migrations_table;
+		$result = $this->db->sql_query($sql);
+
+		while ($migration = $this->db->sql_fetchrow($result))
+		{
+			$this->migration_state[$migration['migration_name']] = $migration;
+
+			$this->migration_state[$migration['migration_name']]['migration_depends_on'] = unserialize($migration['migration_depends_on']);
+		}
+
+		$this->db->sql_freeresult($result);
+	}
+
+	/**
+	* Sets the list of available migration class names to the given array.
+	*
+	* @param array $class_names An array of migration class names
+	* @return null
+	*/
+	public function set_migrations($class_names)
+	{
+		$this->migrations = $class_names;
+	}
+
+	/**
+	* This function adds all migrations in a specified directory to the migrations table
+	*
+	* THIS SHOULD NOT GENERALLY BE USED! THIS IS FOR THE PHPBB INSTALLER.
+	* THIS WILL THROW ERRORS IF MIGRATIONS ALREADY EXIST IN THE TABLE, DO NOT CALL MORE THAN ONCE!
+	*
+	* @param string $path Path to migration data files
+	* @param bool $recursive Set to true to also load data files from subdirectories
+	* @return null
+	*/
+	public function populate_migrations_from_directory($path, $recursive = true)
+	{
+		$existing_migrations = $this->migrations;
+
+		$this->migrations = array();
+		$this->load_migrations($path, true, $recursive);
+
+		foreach ($this->migrations as $name)
+		{
+			if ($this->migration_state($name) === false)
+			{
+				$state = array(
+					'migration_depends_on'	=> $name::depends_on(),
+					'migration_schema_done' => true,
+					'migration_data_done'	=> true,
+					'migration_data_state'	=> '',
+					'migration_start_time'	=> time(),
+					'migration_end_time'	=> time(),
+				);
+				$this->insert_migration($name, $state);
+			}
+		}
+
+		$this->migrations = $existing_migrations;
+	}
+
+	/**
+	* Load migration data files from a directory
+	*
+	* Migration data files loaded with this function MUST contain
+	* 	ONLY ONE class in them (or an exception will be thrown).
+	*
+	* @param string $path Path to migration data files
+	* @param bool $check_fulfillable If TRUE (default), we will check
+	* 	if all of the migrations are fulfillable after loading them.
+	* 	If FALSE, we will not check. You SHOULD check at least once
+	* 	to prevent errors (if including multiple directories, check
+	* 	with the last call to prevent throwing errors unnecessarily).
+	* @param bool $recursive Set to true to also load data files from subdirectories
+	* @return array Array of migration names
+	*/
+	public function load_migrations($path, $check_fulfillable = true, $recursive = true)
+	{
+		if (!is_dir($path))
+		{
+			throw new phpbb_db_migration_exception('DIRECTORY INVALID', $path);
+		}
+
+		$handle = opendir($path);
+		while (($file = readdir($handle)) !== false)
+		{
+			if ($file == '.' || $file == '..')
+			{
+				continue;
+			}
+
+			// Recursion through subdirectories
+			if (is_dir($path . $file) && $recursive)
+			{
+				$this->load_migrations($path . $file . '/', $check_fulfillable, $recursive);
+			}
+
+			if (strpos($file, '_') !== 0 && strrpos($file, '.' . $this->php_ext) === (strlen($file) - strlen($this->php_ext) - 1))
+			{
+				// We try to find what class existed by comparing the classes declared before and after including the file.
+				$declared_classes = get_declared_classes();
+
+				include ($path . $file);
+
+				$added_classes = array_diff(get_declared_classes(), $declared_classes);
+
+				if (
+					// If two classes have been added and phpbb_db_migration is one of them, we've only added one real migration
+					!(sizeof($added_classes) == 2 && in_array('phpbb_db_migration', $added_classes)) &&
+					// Otherwise there should only be one class added
+					sizeof($added_classes) != 1
+				)
+				{
+					throw new phpbb_db_migration_exception('MIGRATION DATA FILE INVALID', $path . $file);
+				}
+
+				$name = array_pop($added_classes);
+
+				if (!in_array($name, $this->migrations))
+				{
+					$this->migrations[] = $name;
+				}
+			}
+		}
+
+		if ($check_fulfillable)
+		{
+			foreach ($this->migrations as $name)
+			{
+				$unfulfillable = $this->unfulfillable($name);
+				if ($unfulfillable !== false)
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_NOT_FULFILLABLE', $name, $unfulfillable);
+				}
+			}
+		}
+
+		return $this->migrations;
+	}
+
+	/**
+	* Runs a single update step from the next migration to be applied.
+	*
+	* The update step can either be a schema or a (partial) data update. To
+	* check if update() needs to be called again use the finished() method.
+	*
+	* @return null
+	*/
+	public function update()
+	{
+		foreach ($this->migrations as $name)
+		{
+			if (!isset($this->migration_state[$name]) ||
+				!$this->migration_state[$name]['migration_schema_done'] ||
+				!$this->migration_state[$name]['migration_data_done'])
+			{
+				if (!$this->try_apply($name))
+				{
+					continue;
+				}
+				else
+				{
+					return;
+				}
+			}
+		}
+	}
+
+	/**
+	* Attempts to apply a step of the given migration or one of its dependencies
+	*
+	* @param	string	The class name of the migration
+	* @return	bool	Whether any update step was successfully run
+	*/
+	protected function try_apply($name)
+	{
+		if (!class_exists($name))
+		{
+			return false;
+		}
+
+		$migration = $this->get_migration($name);
+
+		$state = (isset($this->migration_state[$name])) ?
+			$this->migration_state[$name] :
+			array(
+				'migration_depends_on'	=> $migration->depends_on(),
+				'migration_schema_done' => false,
+				'migration_data_done'	=> false,
+				'migration_data_state'	=> '',
+				'migration_start_time'	=> 0,
+				'migration_end_time'	=> 0,
+			);
+
+		foreach ($state['migration_depends_on'] as $depend)
+		{
+			if (!isset($this->migration_state[$depend]) ||
+				!$this->migration_state[$depend]['migration_schema_done'] ||
+				!$this->migration_state[$depend]['migration_data_done'])
+			{
+				return $this->try_apply($depend);
+			}
+		}
+
+		$this->last_run_migration = array(
+			'name'	=> $name,
+			'class'	=> $migration,
+		);
+
+		if ($migration->effectively_installed())
+		{
+			$state = array(
+				'migration_depends_on'	=> $migration->depends_on(),
+				'migration_schema_done' => true,
+				'migration_data_done'	=> true,
+				'migration_data_state'	=> '',
+				'migration_start_time'	=> 0,
+				'migration_end_time'	=> 0,
+			);
+		}
+		else
+		{
+			if (!isset($this->migration_state[$name]))
+			{
+				$state['migration_start_time'] = time();
+				$this->insert_migration($name, $state);
+			}
+		}
+
+		if (!$state['migration_schema_done'])
+		{
+			$this->apply_schema_changes($migration->update_schema());
+			$state['migration_schema_done'] = true;
+		}
+		else if (!$state['migration_data_done'])
+		{
+			try
+			{
+				$result = $this->process_data_step($migration->update_data(), $state['migration_data_state']);
+
+				$state['migration_data_state'] = ($result === true) ? '' : $result;
+				$state['migration_data_done'] = ($result === true);
+				$state['migration_end_time'] = ($result === true) ? time() : 0;
+			}
+			catch (phpbb_db_migration_exception $e)
+			{
+				// Revert the schema changes
+				$this->revert($name);
+
+				// Rethrow exception
+				throw $e;
+			}
+		}
+
+		$insert = $state;
+		$insert['migration_depends_on'] = serialize($state['migration_depends_on']);
+		$sql = 'UPDATE ' . $this->migrations_table . '
+			SET ' . $this->db->sql_build_array('UPDATE', $insert) . "
+			WHERE migration_name = '" . $this->db->sql_escape($name) . "'";
+		$this->db->sql_query($sql);
+
+		$this->migration_state[$name] = $state;
+
+		return true;
+	}
+
+	/**
+	* Runs a single revert step from the last migration installed
+	*
+	* YOU MUST ADD/SET ALL MIGRATIONS THAT COULD BE DEPENDENT ON THE MIGRATION TO REVERT TO BEFORE CALLING THIS METHOD!
+	* The revert step can either be a schema or a (partial) data revert. To
+	* check if revert() needs to be called again use the migration_state() method.
+	*
+	* @param string $migration String migration name to revert (including any that depend on this migration)
+	* @return null
+	*/
+	public function revert($migration)
+	{
+		if (!isset($this->migration_state[$migration]))
+		{
+			// Not installed
+			return;
+		}
+
+		foreach ($this->migration_state as $name => $state)
+		{
+			if (!empty($state['migration_depends_on']) && in_array($migration, $state['migration_depends_on']))
+			{
+				$this->revert($name);
+			}
+		}
+
+		$this->try_revert($migration);
+	}
+
+	/**
+	* Attempts to revert a step of the given migration or one of its dependencies
+	*
+	* @param	string	The class name of the migration
+	* @return	bool	Whether any update step was successfully run
+	*/
+	protected function try_revert($name)
+	{
+		if (!class_exists($name))
+		{
+			return false;
+		}
+
+		$migration = $this->get_migration($name);
+
+		$state = $this->migration_state[$name];
+
+		$this->last_run_migration = array(
+			'name'	=> $name,
+			'class'	=> $migration,
+		);
+
+		if ($state['migration_data_done'])
+		{
+			if ($state['migration_data_state'] !== 'revert_data')
+			{
+				$result = $this->process_data_step($migration->update_data(), $state['migration_data_state'], true);
+
+				$state['migration_data_state'] = ($result === true) ? 'revert_data' : $result;
+			}
+			else
+			{
+				$result = $this->process_data_step($migration->revert_data(), $state['migration_data_state'], false);
+
+				$state['migration_data_state'] = ($result === true) ? '' : $result;
+				$state['migration_data_done'] = ($result === true) ? false : true;
+			}
+
+			$insert = $state;
+			$insert['migration_depends_on'] = serialize($state['migration_depends_on']);
+			$sql = 'UPDATE ' . $this->migrations_table . '
+				SET ' . $this->db->sql_build_array('UPDATE', $insert) . "
+				WHERE migration_name = '" . $this->db->sql_escape($name) . "'";
+			$this->db->sql_query($sql);
+
+			$this->migration_state[$name] = $state;
+		}
+		else
+		{
+			$this->apply_schema_changes($migration->revert_schema());
+
+			$sql = 'DELETE FROM ' . $this->migrations_table . "
+				WHERE migration_name = '" . $this->db->sql_escape($name) . "'";
+			$this->db->sql_query($sql);
+
+			unset($this->migration_state[$name]);
+		}
+
+		return true;
+	}
+
+	/**
+	* Apply schema changes from a migration
+	*
+	* Just calls db_tools->perform_schema_changes
+	*
+	* @param array $schema_changes from migration
+	*/
+	protected function apply_schema_changes($schema_changes)
+	{
+		$this->db_tools->perform_schema_changes($schema_changes);
+	}
+
+	/**
+	* Process the data step of the migration
+	*
+	* @param array $steps The steps to run
+	* @param bool|string $state Current state of the migration
+	* @param bool $revert true to revert a data step
+	* @return bool|string migration state. True if completed, serialized array if not finished
+	*/
+	protected function process_data_step($steps, $state, $revert = false)
+	{
+		$state = ($state) ? unserialize($state) : false;
+
+		foreach ($steps as $step_identifier => $step)
+		{
+			$last_result = false;
+			if ($state)
+			{
+				// Continue until we reach the step that matches the last step called
+				if ($state['step'] != $step_identifier)
+				{
+					continue;
+				}
+
+				// We send the result from last time to the callable function
+				$last_result = $state['result'];
+
+				// Set state to false since we reached the point we were at
+				$state = false;
+			}
+
+			try
+			{
+				// Result will be null or true if everything completed correctly
+				$result = $this->run_step($step, $last_result, $revert);
+				if ($result !== null && $result !== true)
+				{
+					return serialize(array(
+						'result'	=> $result,
+						'step'		=> $step_identifier,
+					));
+				}
+			}
+			catch (phpbb_db_migration_exception $e)
+			{
+				// We should try rolling back here
+				foreach ($steps as $reverse_step_identifier => $reverse_step)
+				{
+					// If we've reached the current step we can break because we reversed everything that was run
+					if ($reverse_step_identifier == $step_identifier)
+					{
+						break;
+					}
+
+					// Reverse the step that was run
+					$result = $this->run_step($reverse_step, false, !$revert);
+				}
+
+				// rethrow the exception
+				throw $e;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	* Run a single step
+	*
+	* An exception should be thrown if an error occurs
+	*
+	* @param mixed $step Data step from migration
+	* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
+	* @param bool $reverse False to install, True to attempt uninstallation by reversing the call
+	* @return null
+	*/
+	protected function run_step($step, $last_result = false, $reverse = false)
+	{
+		$callable_and_parameters = $this->get_callable_from_step($step, $last_result, $reverse);
+
+		if ($callable_and_parameters === false)
+		{
+			return;
+		}
+
+		$callable = $callable_and_parameters[0];
+		$parameters = $callable_and_parameters[1];
+
+		return call_user_func_array($callable, $parameters);
+	}
+
+	/**
+	* Get a callable statement from a data step
+	*
+	* @param array $step Data step from migration
+	* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
+	* @param bool $reverse False to install, True to attempt uninstallation by reversing the call
+	* @return array Array with parameters for call_user_func_array(), 0 is the callable, 1 is parameters
+	*/
+	protected function get_callable_from_step(array $step, $last_result = false, $reverse = false)
+	{
+		$type = $step[0];
+		$parameters = $step[1];
+
+		$parts = explode('.', $type);
+
+		$class = $parts[0];
+		$method = false;
+
+		if (isset($parts[1]))
+		{
+			$method = $parts[1];
+		}
+
+		switch ($class)
+		{
+			case 'if':
+				if (!isset($parameters[0]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_MISSING_CONDITION', $step);
+				}
+
+				if (!isset($parameters[1]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_MISSING_STEP', $step);
+				}
+
+				$condition = $parameters[0];
+
+				if (!$condition)
+				{
+					return false;
+				}
+
+				$step = $parameters[1];
+
+				return $this->get_callable_from_step($step);
+			break;
+			case 'custom':
+				if (!is_callable($parameters[0]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_CUSTOM_NOT_CALLABLE', $step);
+				}
+
+				return array(
+					$parameters[0],
+					array($last_result),
+				);
+			break;
+
+			default:
+				if (!$method)
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNKNOWN_TYPE', $step);
+				}
+
+				if (!isset($this->tools[$class]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNDEFINED_TOOL', $step);
+				}
+
+				if (!method_exists(get_class($this->tools[$class]), $method))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNDEFINED_METHOD', $step);
+				}
+
+				// Attempt to reverse operations
+				if ($reverse)
+				{
+					array_unshift($parameters, $method);
+
+					return array(
+						array($this->tools[$class], 'reverse'),
+						$parameters,
+					);
+				}
+
+				return array(
+					array($this->tools[$class], $method),
+					$parameters,
+				);
+			break;
+		}
+	}
+
+	/**
+	* Insert migration row into the database
+	*
+	* @param string $name Name of the migration
+	* @param array $state
+	* @return null
+	*/
+	protected function insert_migration($name, $state)
+	{
+		$migration_row = $state;
+		$migration_row['migration_name'] = $name;
+		$migration_row['migration_depends_on'] = serialize($state['migration_depends_on']);
+
+		$sql = 'INSERT INTO ' . $this->migrations_table . '
+			' . $this->db->sql_build_array('INSERT', $migration_row);
+		$this->db->sql_query($sql);
+
+		$this->migration_state[$name] = $state;
+	}
+
+	/**
+	* Checks if a migration's dependencies can even theoretically be satisfied.
+	*
+	* @param string	$name The class name of the migration
+	* @return bool|string False if fulfillable, string of missing migration name if unfulfillable
+	*/
+	public function unfulfillable($name)
+	{
+		if (isset($this->migration_state[$name]))
+		{
+			return false;
+		}
+
+		if (!class_exists($name))
+		{
+			return $name;
+		}
+
+		$migration = $this->get_migration($name);
+		$depends = $migration->depends_on();
+
+		foreach ($depends as $depend)
+		{
+			$unfulfillable = $this->unfulfillable($depend);
+			if ($unfulfillable !== false)
+			{
+				return $unfulfillable;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	* Checks whether all available, fulfillable migrations have been applied.
+	*
+	* @return bool Whether the migrations have been applied
+	*/
+	public function finished()
+	{
+		foreach ($this->migrations as $name)
+		{
+			if (!isset($this->migration_state[$name]))
+			{
+				// skip unfulfillable migrations, but fulfillables mean we
+				// are not finished yet
+				if ($this->unfulfillable($name) !== false)
+				{
+					continue;
+				}
+				return false;
+			}
+
+			$migration = $this->migration_state[$name];
+
+			if (!$migration['migration_schema_done'] || !$migration['migration_data_done'])
+			{
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	* Gets a migration state (whether it is installed and to what extent)
+	*
+	* @param string $migration String migration name to check if it is installed
+	* @return bool|array False if the migration has not at all been installed, array
+	*/
+	public function migration_state($migration)
+	{
+		if (!isset($this->migration_state[$migration]))
+		{
+			return false;
+		}
+
+		return $this->migration_state[$migration];
+	}
+
+	/**
+	* Helper to get a migration
+	*
+	* @param string $name Name of the migration
+	* @return phpbb_db_migration
+	*/
+	protected function get_migration($name)
+	{
+		return new $name($this->config, $this->db, $this->db_tools, $this->phpbb_root_path, $this->php_ext, $this->table_prefix);
+	}
+}