diff --git a/admin/system/database.php b/admin/system/database.php
index e38a917..ac6ffd7 100644
--- a/admin/system/database.php
+++ b/admin/system/database.php
@@ -66,12 +66,12 @@ if ($operation == 'export') {
 				$tables = C::t('setting') -> fetch('custombackup', true);
 			} else {
 				C::t('setting') -> update('custombackup', empty($_GET['customtables']) ? '' : $_GET['customtables']);
-				$tables = &$_GET['customtables'];
+				$tables = $_GET['customtables'];
 			}
 
 			//验证表名是否正确
 			foreach($tables as $key => $table){
-				if(!in_array($table,$alltabls)) unset($tables[$key]);
+				if(!in_array($table,$alltables)) unset($tables[$key]);
 			}
 			if (!is_array($tables) || empty($tables)) {
 				showmessage('database_export_custom_invalid');
@@ -85,7 +85,7 @@ if ($operation == 'export') {
 		}
 
 		$volume = intval($_GET['volume']) + 1;
-		$idstring = '# Identify: ' . base64_encode("$_G[timestamp]," . $_G['setting']['version'] . ",{$_GET['type']},{$_GET['method']},{$volume},{$tablepre},{$dbcharset}") . "\n";
+		$idstring = '# Identify: ' . base64_encode($_G['timestamp']."," . $_G['setting']['version'] . "," .$_GET['type']."," .$_GET['method']."," .$volume."," .$tablepre."," .$dbcharset) . "\n";
 		$dumpcharset = $_GET['sqlcharset'] ? $_GET['sqlcharset'] : str_replace('-', '', $_G['charset']);
 		$setnames = ($_GET['sqlcharset'] && $db -> version() > '4.1' && (!$_GET['sqlcompat'] || $_GET['sqlcompat'] == 'MYSQL41')) ? "SET NAMES '$dumpcharset';\n\n" : '';
 		if ($db -> version() > '4.1') {
@@ -498,7 +498,7 @@ function sqldumptablestruct($table) {
 	}
 
 	$tablestatus = DB::fetch_first("SHOW TABLE STATUS LIKE '$table'");
-	$tabledump .= ($tablestatus['Auto_increment'] ? " AUTO_INCREMENT=$tablestatus[Auto_increment]" : ''). ";\n\n";
+	$tabledump .= ($tablestatus['Auto_increment'] ? (" AUTO_INCREMENT=".$tablestatus['Auto_increment']) : ''). ";\n\n";
 	if ($_GET['sqlcompat'] == 'MYSQL40' && $db -> version() >= '4.1' && $db -> version() < '5.1') {
 		if ($tablestatus['Auto_increment'] <> '') {
 			$temppos = strpos($tabledump, ',');
@@ -539,7 +539,7 @@ function sqldumptable($table, $startfrom = 0, $currsize = 0) {
 		if ($_GET['extendins'] == '0') {
 			while ($currsize + strlen($tabledump) + 500 < $_GET['sizelimit'] * 1000 && $numrows == $offset) {
 				if ($firstfield['Extra'] == 'auto_increment') {
-					$selectsql = "SELECT * FROM $table WHERE $firstfield[Field] > $startfrom ORDER BY $firstfield[Field] LIMIT $offset";
+					$selectsql = "SELECT * FROM $table WHERE ".$firstfield['Field']." > ".$startfrom." ORDER BY ".$firstfield['Field']." LIMIT " .$offset;
 				} else {
 					$selectsql = "SELECT * FROM $table LIMIT $startfrom, $offset";
 				}
@@ -570,7 +570,7 @@ function sqldumptable($table, $startfrom = 0, $currsize = 0) {
 		} else {
 			while ($currsize + strlen($tabledump) + 500 < $_GET['sizelimit'] * 1000 && $numrows == $offset) {
 				if ($firstfield['Extra'] == 'auto_increment') {
-					$selectsql = "SELECT * FROM $table WHERE $firstfield[Field] > $startfrom LIMIT $offset";
+					$selectsql = "SELECT * FROM $table WHERE ".$firstfield['Field']." > ".$startfrom." LIMIT " .$offset;
 				} else {
 					$selectsql = "SELECT * FROM $table LIMIT $startfrom, $offset";
 				}