/**

*

* @package install

* @version $Id: install_convert.php 8814 2008-09-04 12:01:47Z acydburn $

* @copyright (c) 2006 phpBB Group

* @license http://opensource.org/licenses/gpl-license.php GNU Public License

*

*/

/**

*/

if (!defined('IN_INSTALL'))

{

	// Someone has tried to access the file direct. This is not a good idea, so exit

	exit;

}

if (!empty($setmodules))

{

	$module[] = array(

		'module_type'		=> 'install',

		'module_title'		=> 'CONVERT',

		'module_filename'	=> substr(basename(__FILE__), 0, -strlen($phpEx)-1),

		'module_order'		=> 20,

		'module_subs'		=> '',

		'module_stages'		=> array('INTRO', 'SETTINGS', 'IN_PROGRESS', 'FINAL'),

		'module_reqs'		=> ''

	);

}

/**

* Class holding all convertor-specific details.

* @package install

*/

class convert

{

	var $options = array();

	var $convertor_tag = '';

	var $src_dbms = '';

	var $src_dbhost = '';

	var $src_dbport = '';

	var $src_dbuser = '';

	var $src_dbpasswd = '';

	var $src_dbname = '';

	var $src_table_prefix = '';

	var $convertor_data = array();

	var $tables = array();

	var $config_schema = array();

	var $convertor = array();

	var $src_truncate_statement = 'DELETE FROM ';

	var $truncate_statement = 'DELETE FROM ';

	var $fulltext_search;

	// Batch size, can be adjusted by the conversion file

	// For big boards a value of 6000 seems to be optimal

	var $batch_size = 2000;

	// Number of rows to be inserted at once (extended insert) if supported

	// For installations having enough memory a value of 60 may be good.

	var $num_wait_rows = 20;

	// Mysqls internal recoding engine messing up with our (better) functions? We at least support more encodings than mysql so should use it in favor.

	var $mysql_convert = false;

	var $p_master;

	function convert(&$p_master)

	{

		$this->p_master = &$p_master;

	}

}

/**

* Convert class for conversions

* @package install

*/

class install_convert extends module

{

	/**

	* Variables used while converting, they are accessible from the global variable $convert

	*/

	function install_convert(&$p_master)

	{

		$this->p_master = &$p_master;

	}

	function main($mode, $sub)

	{

		global $lang, $template, $phpbb_root_path, $phpEx, $cache, $config, $language, $table_prefix;

		global $convert;

		$this->tpl_name = 'install_convert';

		$this->mode = $mode;

		$convert = new convert($this->p_master);

		switch ($sub)

		{

			case 'intro':

				// Try opening config file

				// @todo If phpBB is not installed, we need to do a cut-down installation here

				// For now, we redirect to the installation script instead

				if (@file_exists($phpbb_root_path . 'config.' . $phpEx))

				{

					include($phpbb_root_path . 'config.' . $phpEx);

				}

				if (!defined('PHPBB_INSTALLED'))

				{

					$template->assign_vars(array(

						'S_NOT_INSTALLED'		=> true,

						'TITLE'					=> $lang['BOARD_NOT_INSTALLED'],

						'BODY'					=> sprintf($lang['BOARD_NOT_INSTALLED_EXPLAIN'], append_sid($phpbb_root_path . 'install/index.' . $phpEx, 'mode=install&language=' . $language)),

					));

					return;

				}

				require($phpbb_root_path . 'config.' . $phpEx);

				require($phpbb_root_path . 'includes/constants.' . $phpEx);

				require($phpbb_root_path . 'includes/db/' . $dbms . '.' . $phpEx);

				require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);

				$db = new $sql_db();

				$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);

				unset($dbpasswd);

				// We need to fill the config to let internal functions correctly work

				$sql = 'SELECT *

					FROM ' . CONFIG_TABLE;

				$result = $db->sql_query($sql);

				$config = array();

				while ($row = $db->sql_fetchrow($result))

				{

					$config[$row['config_name']] = $row['config_value'];

				}

				$db->sql_freeresult($result);

				// Detect if there is already a conversion in progress at this point and offer to resume

				// It's quite possible that the user will get disconnected during a large conversion so they need to be able to resume it

				$new_conversion = request_var('new_conv', 0);

				if ($new_conversion)

				{

					$config['convert_progress'] = '';

					$config['convert_db_server'] = '';

					$config['convert_db_user'] = '';

					$db->sql_query('DELETE FROM ' . CONFIG_TABLE . "

						WHERE config_name = 'convert_progress'

							OR config_name = 'convert_db_server'

							OR config_name = 'convert_db_user'"

					);

				}

				// Let's see if there is a conversion in the works...

				$options = array();

				if (!empty($config['convert_progress']) && !empty($config['convert_db_server']) && !empty($config['convert_db_user']) && !empty($config['convert_options']))

				{

					$options = unserialize($config['convert_progress']);

					$options = array_merge($options, unserialize($config['convert_db_server']), unserialize($config['convert_db_user']), unserialize($config['convert_options']));

				}

				// This information should have already been checked once, but do it again for safety

				if (!empty($options) && !empty($options['tag']) &&

					isset($options['dbms']) &&

					isset($options['dbhost']) &&

					isset($options['dbport']) &&

					isset($options['dbuser']) &&

					isset($options['dbpasswd']) &&

					isset($options['dbname']) &&

					isset($options['table_prefix']))

				{

					$this->page_title = $lang['CONTINUE_CONVERT'];

					$template->assign_vars(array(

						'TITLE'			=> $lang['CONTINUE_CONVERT'],

						'BODY'			=> $lang['CONTINUE_CONVERT_BODY'],

						'L_NEW'			=> $lang['CONVERT_NEW_CONVERSION'],

						'L_CONTINUE'	=> $lang['CONTINUE_OLD_CONVERSION'],

						'S_CONTINUE'	=> true,

						'U_NEW_ACTION'		=> $this->p_master->module_url . "?mode={$this->mode}&sub=intro&new_conv=1&language=$language",

						'U_CONTINUE_ACTION'	=> $this->p_master->module_url . "?mode={$this->mode}&sub=in_progress&tag={$options['tag']}{$options['step']}&language=$language",

					));

					return;

				}

				$this->list_convertors($sub);

			break;

			case 'settings':

				$this->get_convert_settings($sub);

			break;

			case 'in_progress':

				$this->convert_data($sub);

			break;

			case 'final':

				$this->page_title = $lang['CONVERT_COMPLETE'];

				$template->assign_vars(array(

					'TITLE'		=> $lang['CONVERT_COMPLETE'],

					'BODY'		=> $lang['CONVERT_COMPLETE_EXPLAIN'],

				));

				// If we reached this step (conversion completed) we want to purge the cache and log the user out.

				// This is for making sure the session get not screwed due to the 3.0.x users table being completely new.

				$cache->purge();

				require($phpbb_root_path . 'config.' . $phpEx);

				require($phpbb_root_path . 'includes/constants.' . $phpEx);

				require($phpbb_root_path . 'includes/db/' . $dbms . '.' . $phpEx);

				require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);

				$db = new $sql_db();

				$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);

				unset($dbpasswd);

				$sql = 'SELECT config_value

					FROM ' . CONFIG_TABLE . '

					WHERE config_name = \'search_type\'';

				$result = $db->sql_query($sql);

				if ($db->sql_fetchfield('config_value') != 'fulltext_mysql')

				{

					$template->assign_vars(array(

						'S_ERROR_BOX'	=> true,

						'ERROR_TITLE'	=> $lang['SEARCH_INDEX_UNCONVERTED'],

						'ERROR_MSG'		=> $lang['SEARCH_INDEX_UNCONVERTED_EXPLAIN'],

					));

				}

				switch ($db->sql_layer)

				{

					case 'sqlite':

					case 'firebird':

						$db->sql_query('DELETE FROM ' . SESSIONS_KEYS_TABLE);

						$db->sql_query('DELETE FROM ' . SESSIONS_TABLE);

					break;

					default:

						$db->sql_query('TRUNCATE TABLE ' . SESSIONS_KEYS_TABLE);

						$db->sql_query('TRUNCATE TABLE ' . SESSIONS_TABLE);

					break;

				}

			break;

		}

	}

	/**

	* Generate a list of all available conversion modules

	*/

	function list_convertors($sub)

	{

		global $lang, $language, $template, $phpbb_root_path, $phpEx;

		$this->page_title = $lang['SUB_INTRO'];

		$template->assign_vars(array(

			'TITLE'		=> $lang['CONVERT_INTRO'],

			'BODY'		=> $lang['CONVERT_INTRO_BODY'],

			'L_AUTHOR'					=> $lang['AUTHOR'],

			'L_AVAILABLE_CONVERTORS'	=> $lang['AVAILABLE_CONVERTORS'],

			'L_CONVERT'					=> $lang['CONVERT'],

			'L_NO_CONVERTORS'			=> $lang['NO_CONVERTORS'],

			'L_OPTIONS'					=> $lang['CONVERT_OPTIONS'],

			'L_SOFTWARE'				=> $lang['SOFTWARE'],

			'L_VERSION'					=> $lang['VERSION'],

			'S_LIST'	=> true,

		));

		$convertors = $sort = array();

		$get_info = true;

		$handle = @opendir('./convertors/');

		if (!$handle)

		{

			$this->error('Unable to access the convertors directory', __LINE__, __FILE__);

		}

		while ($entry = readdir($handle))

		{

			if (preg_match('/^convert_([a-z0-9_]+).' . $phpEx . '$/i', $entry, $m))

			{

				include('./convertors/' . $entry);

				if (isset($convertor_data))

				{

					$sort[strtolower($convertor_data['forum_name'])] = sizeof($convertors);

					$convertors[] = array(

						'tag'			=>	$m[1],

						'forum_name'	=>	$convertor_data['forum_name'],

						'version'		=>	$convertor_data['version'],

						'dbms'			=>	$convertor_data['dbms'],

						'dbhost'		=>	$convertor_data['dbhost'],

						'dbport'		=>	$convertor_data['dbport'],

						'dbuser'		=>	$convertor_data['dbuser'],

						'dbpasswd'		=>	$convertor_data['dbpasswd'],

						'dbname'		=>	$convertor_data['dbname'],

						'table_prefix'	=>	$convertor_data['table_prefix'],

						'author'		=>	$convertor_data['author']

					);

				}

				unset($convertor_data);

			}

		}

		closedir($handle);

		@ksort($sort);

		foreach ($sort as $void => $index)

		{

			$template->assign_block_vars('convertors', array(

				'AUTHOR'	=> $convertors[$index]['author'],

				'SOFTWARE'	=> $convertors[$index]['forum_name'],

				'VERSION'	=> $convertors[$index]['version'],

				'U_CONVERT'	=> $this->p_master->module_url . "?mode={$this->mode}&language=$language&sub=settings&tag=" . $convertors[$index]['tag'],

			));

		}

	}

	/**

	*/

	function get_convert_settings($sub)

	{

		global $lang, $language, $template, $db, $phpbb_root_path, $phpEx, $config, $cache;

		require($phpbb_root_path . 'config.' . $phpEx);

		require($phpbb_root_path . 'includes/constants.' . $phpEx);

		require($phpbb_root_path . 'includes/db/' . $dbms . '.' . $phpEx);

		require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);

		$db = new $sql_db();

		$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);

		unset($dbpasswd);

		$this->page_title = $lang['STAGE_SETTINGS'];

		// We need to fill the config to let internal functions correctly work

		$sql = 'SELECT *

			FROM ' . CONFIG_TABLE;

		$result = $db->sql_query($sql);

		$config = array();

		while ($row = $db->sql_fetchrow($result))

		{

			$config[$row['config_name']] = $row['config_value'];

		}

		$db->sql_freeresult($result);

		$convertor_tag = request_var('tag', '');

		if (empty($convertor_tag))

		{

			$this->p_master->error($lang['NO_CONVERT_SPECIFIED'], __LINE__, __FILE__);

		}

		$get_info = true;

		// check security implications of direct inclusion

		$convertor_tag = basename($convertor_tag);

		if (!file_exists('./convertors/convert_' . $convertor_tag . '.' . $phpEx))

		{

			$this->p_master->error($lang['CONVERT_NOT_EXIST'], __LINE__, __FILE__);

		}

		include('./convertors/convert_' . $convertor_tag . '.' . $phpEx);

		// The test_file is a file that should be present in the location of the old board.

		if (!isset($test_file))

		{

			$this->p_master->error($lang['DEV_NO_TEST_FILE'], __LINE__, __FILE__);

		}

		$submit = (isset($_POST['submit'])) ? true : false;

		$src_dbms			= request_var('src_dbms', $convertor_data['dbms']);

		$src_dbhost			= request_var('src_dbhost', $convertor_data['dbhost']);

		$src_dbport			= request_var('src_dbport', $convertor_data['dbport']);

		$src_dbuser			= request_var('src_dbuser', $convertor_data['dbuser']);

		$src_dbpasswd		= request_var('src_dbpasswd', $convertor_data['dbpasswd']);

		$src_dbname			= request_var('src_dbname', $convertor_data['dbname']);

		$src_table_prefix	= request_var('src_table_prefix', $convertor_data['table_prefix']);

		$forum_path			= request_var('forum_path', $convertor_data['forum_path']);

		$refresh			= request_var('refresh', 1);

		// Default URL of the old board

		// @todo Are we going to use this for attempting to convert URL references in posts, or should we remove it?

		//		-> We should convert old urls to the new relative urls format

		// $src_url = request_var('src_url', 'Not in use at the moment');

		// strip trailing slash from old forum path

		$forum_path = (strlen($forum_path) && $forum_path[strlen($forum_path) - 1] == '/') ? substr($forum_path, 0, -1) : $forum_path;

		$error = array();

		if ($submit)

		{

			if (!@file_exists('./../' . $forum_path . '/' . $test_file))

			{

				$error[] = sprintf($lang['COULD_NOT_FIND_PATH'], $forum_path);

			}

			$connect_test = false;

			$available_dbms = get_available_dbms(false, true, true);

			if (!isset($available_dbms[$src_dbms]) || !$available_dbms[$src_dbms]['AVAILABLE'])

			{

				$error['db'][] = $lang['INST_ERR_NO_DB'];

				$connect_test = false;

			}

			else

			{

				$connect_test = connect_check_db(true, $error, $available_dbms[$src_dbms], $src_table_prefix, $src_dbhost, $src_dbuser, htmlspecialchars_decode($src_dbpasswd), $src_dbname, $src_dbport, true, ($src_dbms == $dbms) ? false : true, false);

			}

			// The forum prefix of the old and the new forum can only be the same if two different databases are used.

			if ($src_table_prefix == $table_prefix && $src_dbms == $dbms && $src_dbhost == $dbhost && $src_dbport == $dbport && $src_dbname == $dbname)

			{

				$error[] = sprintf($lang['TABLE_PREFIX_SAME'], $src_table_prefix);

			}

			// Check table prefix

			if (!sizeof($error))

			{

				// initiate database connection to old db if old and new db differ

				global $src_db, $same_db;

				$src_db = $same_db = false;

				if ($src_dbms != $dbms || $src_dbhost != $dbhost || $src_dbport != $dbport || $src_dbname != $dbname || $src_dbuser != $dbuser)

				{

					$sql_db = 'dbal_' . $src_dbms;

					$src_db = new $sql_db();

					$src_db->sql_connect($src_dbhost, $src_dbuser, htmlspecialchars_decode($src_dbpasswd), $src_dbname, $src_dbport, false, true);

					$same_db = false;

				}

				else

				{

					$src_db = $db;

					$same_db = true;

				}

				$src_db->sql_return_on_error(true);

				$db->sql_return_on_error(true);

				// Try to select one row from the first table to see if the prefix is OK

				$result = $src_db->sql_query_limit('SELECT * FROM ' . $src_table_prefix . $tables[0], 1);

				if (!$result)

				{

					$prefixes = array();

					$tables_existing = get_tables($src_db);

					$tables_existing = array_map('strtolower', $tables_existing);

					foreach ($tables_existing as $table_name)

					{

						compare_table($tables, $table_name, $prefixes);

					}

					unset($tables_existing);

					foreach ($prefixes as $prefix => $count)

					{

						if ($count >= sizeof($tables))

						{

							$possible_prefix = $prefix;

							break;

						}

					}

					$msg = '';

					if (!empty($convertor_data['table_prefix']))

					{

						$msg .= sprintf($lang['DEFAULT_PREFIX_IS'], $convertor_data['forum_name'], $convertor_data['table_prefix']);

					}

					if (!empty($possible_prefix))

					{

						$msg .= '
';

						$msg .= ($possible_prefix == '*') ? $lang['BLANK_PREFIX_FOUND'] : sprintf($lang['PREFIX_FOUND'], $possible_prefix);

						$src_table_prefix = ($possible_prefix == '*') ? '' : $possible_prefix;

					}

					$error[] = $msg;

				}

				$src_db->sql_freeresult($result);

				$src_db->sql_return_on_error(false);

			}

			if (!sizeof($error))

			{

				// Save convertor Status

				set_config('convert_progress', serialize(array(

					'step'			=> '',

					'table_prefix'	=> $src_table_prefix,

					'tag'			=> $convertor_tag,

				)), true);

				set_config('convert_db_server', serialize(array(

					'dbms'			=> $src_dbms,

					'dbhost'		=> $src_dbhost,

					'dbport'		=> $src_dbport,

					'dbname'		=> $src_dbname,

				)), true);

				set_config('convert_db_user', serialize(array(

					'dbuser'		=> $src_dbuser,

					'dbpasswd'		=> $src_dbpasswd,

				)), true);

				// Save options

				set_config('convert_options', serialize(array('forum_path' => './../' . $forum_path, 'refresh' => $refresh)), true);

				$template->assign_block_vars('checks', array(

					'TITLE'		=> $lang['VERIFY_OPTIONS'],

					'RESULT'	=> $lang['CONVERT_SETTINGS_VERIFIED'],

				));

				$template->assign_vars(array(

					'L_SUBMIT'	=> $lang['BEGIN_CONVERT'],

//					'S_HIDDEN'	=> $s_hidden_fields,

					'U_ACTION'	=> $this->p_master->module_url . "?mode={$this->mode}&sub=in_progress&tag=$convertor_tag&language=$language",

				));

				return;

			}

			else

			{

				$template->assign_block_vars('checks', array(

					'TITLE'		=> $lang['VERIFY_OPTIONS'],

					'RESULT'	=> '' . implode('
', $error) . '',

				));

			}

		} // end submit

		foreach ($this->convert_options as $config_key => $vars)

		{

			if (!is_array($vars) && strpos($config_key, 'legend') === false)

			{

				continue;

			}

			if (strpos($config_key, 'legend') !== false)

			{

				$template->assign_block_vars('options', array(

					'S_LEGEND'		=> true,

					'LEGEND'		=> $lang[$vars])

				);

				continue;

			}

			$options = isset($vars['options']) ? $vars['options'] : '';

			$template->assign_block_vars('options', array(

				'KEY'			=> $config_key,

				'TITLE'			=> $lang[$vars['lang']],

				'S_EXPLAIN'		=> $vars['explain'],

				'S_LEGEND'		=> false,

				'TITLE_EXPLAIN'	=> ($vars['explain']) ? $lang[$vars['lang'] . '_EXPLAIN'] : '',

				'CONTENT'		=> $this->p_master->input_field($config_key, $vars['type'], $$config_key, $options),

				)

			);

		}

		$template->assign_vars(array(

			'TITLE'		=> $lang['STAGE_SETTINGS'],

			'BODY'		=> $lang['CONV_OPTIONS_BODY'],

			'L_SUBMIT'	=> $lang['BEGIN_CONVERT'],

			'U_ACTION'	=> $this->p_master->module_url . "?mode={$this->mode}&sub=settings&tag=$convertor_tag&language=$language",

		));

	}

	/**

	* The function which does the actual work (or dispatches it to the relevant places)

	*/

	function convert_data($sub)

	{

		global $template, $user, $phpbb_root_path, $phpEx, $db, $lang, $config, $cache;

		global $convert, $convert_row, $message_parser, $skip_rows, $language;

		require($phpbb_root_path . 'config.' . $phpEx);

		require($phpbb_root_path . 'includes/constants.' . $phpEx);

		require($phpbb_root_path . 'includes/db/' . $dbms . '.' . $phpEx);

		require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);

		$db = new $sql_db();

		$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);

		unset($dbpasswd);

		$sql = 'SELECT *

			FROM ' . CONFIG_TABLE;

		$result = $db->sql_query($sql);

		$config = array();

		while ($row = $db->sql_fetchrow($result))

		{

			$config[$row['config_name']] = $row['config_value'];

		}

		$db->sql_freeresult($result);

		// Override a couple of config variables for the duration

		$config['max_quote_depth'] = 0;

		// @todo Need to confirm that max post length in source is <= max post length in destination or there may be interesting formatting issues

		$config['max_post_chars'] = 0;

		// Set up a user as well. We _should_ have enough of a database here at this point to do this

		// and it helps for any core code we call

		$user->session_begin();

		$user->page = $user->extract_current_page($phpbb_root_path);

		// This is a little bit of a fudge, but it allows the language entries to be available to the

		// core code without us loading them again

		$user->lang = &$lang;

		$this->page_title = $user->lang['STAGE_IN_PROGRESS'];

		$convert->options = array();

		if (isset($config['convert_progress']))

		{

			$convert->options = unserialize($config['convert_progress']);

			$convert->options = array_merge($convert->options, unserialize($config['convert_db_server']), unserialize($config['convert_db_user']), unserialize($config['convert_options']));

		}

		// This information should have already been checked once, but do it again for safety

		if (empty($convert->options) || empty($convert->options['tag']) ||

			!isset($convert->options['dbms']) ||

			!isset($convert->options['dbhost']) ||

			!isset($convert->options['dbport']) ||

			!isset($convert->options['dbuser']) ||

			!isset($convert->options['dbpasswd']) ||

			!isset($convert->options['dbname']) ||

			!isset($convert->options['table_prefix']))

		{

			$this->p_master->error($user->lang['NO_CONVERT_SPECIFIED'], __LINE__, __FILE__);

		}

		// Make some short variables accessible, for easier referencing

		$convert->convertor_tag = basename($convert->options['tag']);

		$convert->src_dbms = $convert->options['dbms'];

		$convert->src_dbhost = $convert->options['dbhost'];

		$convert->src_dbport = $convert->options['dbport'];

		$convert->src_dbuser = $convert->options['dbuser'];

		$convert->src_dbpasswd = $convert->options['dbpasswd'];

		$convert->src_dbname = $convert->options['dbname'];

		$convert->src_table_prefix = $convert->options['table_prefix'];

		// initiate database connection to old db if old and new db differ

		global $src_db, $same_db;

		$src_db = $same_db = null;

		if ($convert->src_dbms != $dbms || $convert->src_dbhost != $dbhost || $convert->src_dbport != $dbport || $convert->src_dbname != $dbname || $convert->src_dbuser != $dbuser)

		{

			if ($convert->src_dbms != $dbms)

			{

				require($phpbb_root_path . 'includes/db/' . $convert->src_dbms . '.' . $phpEx);

			}

			$sql_db = 'dbal_' . $convert->src_dbms;

			$src_db = new $sql_db();

			$src_db->sql_connect($convert->src_dbhost, $convert->src_dbuser, htmlspecialchars_decode($convert->src_dbpasswd), $convert->src_dbname, $convert->src_dbport, false, true);

			$same_db = false;

		}

		else

		{

			$src_db = $db;

			$same_db = true;

		}

		$convert->mysql_convert = false;

		switch ($src_db->sql_layer)

		{

			case 'sqlite':

			case 'firebird':

				$convert->src_truncate_statement = 'DELETE FROM ';

			break;

			// Thanks MySQL, for silently converting...

			case 'mysql':

			case 'mysql4':

				if (version_compare($src_db->sql_server_info(true), '4.1.3', '>='))

				{

					$convert->mysql_convert = true;

				}

				$convert->src_truncate_statement = 'TRUNCATE TABLE ';

			break;

			case 'mysqli':

				$convert->mysql_convert = true;

				$convert->src_truncate_statement = 'TRUNCATE TABLE ';

			break;

			default:

				$convert->src_truncate_statement = 'TRUNCATE TABLE ';

			break;

		}

		if ($convert->mysql_convert && !$same_db)

		{

			$src_db->sql_query("SET NAMES 'binary'");

		}

		switch ($db->sql_layer)

		{

			case 'sqlite':

			case 'firebird':

				$convert->truncate_statement = 'DELETE FROM ';

			break;

			default:

				$convert->truncate_statement = 'TRUNCATE TABLE ';