Slim db persistent connection (#3724)

frameworks/PHP/slim/index.php

@@ -5,10 +5,11 @@ require_once __DIR__.'/vendor/autoload.php';
 
 $app = new Slim\App(array(
     'db' => function ($c) {
-        $pdo = new PDO('mysql:host=tfb-database;dbname=hello_world;charset=utf8', 'benchmarkdbuser', 'benchmarkdbpass');
+        $pdo = new PDO('mysql:host=tfb-database;dbname=hello_world;charset=utf8', 'benchmarkdbuser', 'benchmarkdbpass', array(
+            PDO::ATTR_PERSISTENT => true,
+        ));
         $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
         $pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
-        $pdo->setAttribute(PDO::ATTR_PERSISTENT, true);
 
         return $pdo;
     },