diff --git a/functions-5-2.php b/functions-5-2.php
index 545b653..2399535 100644
--- a/functions-5-2.php
+++ b/functions-5-2.php
@@ -56,7 +56,8 @@ class PDOSQLiteUDFS {
       'lcase'          => 'lcase',
       'inet_ntoa'      => 'inet_ntoa',
       'inet_aton'      => 'inet_aton',
-      'datediff'       => 'datediff'
+      'datediff'       => 'datediff',
+  		'locate'         => 'locate'
   );
 
   public function month($field){
@@ -366,5 +367,23 @@ class PDOSQLiteUDFS {
     $interval = floor(($end_date - $start_date)/(3600*24));
     return $interval;
   }
+  /**
+   * emulates MySQL LOCATE() function
+   */
+  public function locate($substr, $str, $pos = 0) {
+  	if (!extension_loaded('mbstring')) {
+  		if (($val = stros($str, $substr, $pos)) !== false) {
+  			return $val + 1;
+  		} else {
+  			return 0;
+  		}
+  	} else {
+	  	if (($val = mb_strpos($str, $substr, $pos)) !== false) {
+	  		return $val + 1;
+	  	} else {
+	  		return 0;
+	  	}
+  	}
+  }
 }
 ?>
\ No newline at end of file
diff --git a/functions.php b/functions.php
index 5f7af23..9caaf24 100644
--- a/functions.php
+++ b/functions.php
@@ -57,7 +57,8 @@ class PDOSQLiteUDFS {
       'lcase'          => 'lcase',
       'inet_ntoa'      => 'inet_ntoa',
       'inet_aton'      => 'inet_aton',
-      'datediff'       => 'datediff'
+      'datediff'       => 'datediff',
+  		'locate'         => 'locate'
   );
 
   public function month($field){
@@ -340,5 +341,23 @@ class PDOSQLiteUDFS {
       return $interval->format('%r%a');
     }
   }
+  /**
+   * emulates MySQL LOCATE() function
+   */
+  public function locate($substr, $str, $pos = 0) {
+  	if (!extension_loaded('mbstring')) {
+  		if (($val = stros($str, $substr, $pos)) !== false) {
+  			return $val + 1;
+  		} else {
+  			return 0;
+  		}
+  	} else {
+	  	if (($val = mb_strpos($str, $substr, $pos)) !== false) {
+	  		return $val + 1;
+	  	} else {
+	  		return 0;
+	  	}
+  	}
+  }
 }
 ?>
\ No newline at end of file
diff --git a/pdoengine.class.php b/pdoengine.class.php
index 2e2521a..d12e9d2 100644
--- a/pdoengine.class.php
+++ b/pdoengine.class.php
@@ -35,11 +35,9 @@ class PDOEngine extends PDO {
 
   /**
    * Constructor
-   * registers __destruct function and initialize the database environment
    * @param array $DatabaseParams
    */
   function __construct() {
-    register_shutdown_function(array($this, '__destruct'));
     $this->init();
   }
   function __destruct() {
diff --git a/readme-ja.txt b/readme-ja.txt
index d8ceb27..5d7ca86 100644
--- a/readme-ja.txt
+++ b/readme-ja.txt
@@ -7,7 +7,7 @@ Author: Kojima Toshiyasu
 Author URI: http://dogwood.skr.jp/
 Requires at least: 3.3
 Tested up to: 3.5.2
-Stable tag: 1.0
+Stable tag: 1.1
 License: GPLv2
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 
@@ -162,6 +162,11 @@ wp-config.phpの準備が終わったら、次のステップに進みます。
 
 == Changelog ==
 
+= 1.1 (2013-07-24) =
+* DROP INDEX 単独のクエリが動作していなかったのを修正しました。
+* shutdown_hook で descructor を実行していたのをやめました。
+* LOCATE() 関数を使えるようにしました。
+
 = 1.0 (2013-07-07) =
 最初のリリース。
 
diff --git a/readme.txt b/readme.txt
index 967e6d9..a00499a 100644
--- a/readme.txt
+++ b/readme.txt
@@ -7,7 +7,7 @@ Author: Kojima Toshiyasu
 Author URI: http://dogwood.skr.jp/
 Requires at least: 3.3
 Tested up to: 3.5.2
-Stable tag: 1.0
+Stable tag: 1.1
 License: GPLv2
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 
@@ -154,6 +154,11 @@ Probably there are more, I'm afraid.
 
 == Changelog ==
 
+= 1.1 (2013-07-24) =
+* Fixed the manipulation of DROP INDEX query.
+* Removed desctructor() from shutdown_hook.
+* Enabled LOCATE() function in the query string.
+
 = 1.0 (2013-07-07) =
 First release version of the plugin.