added Order, Limit, Skip methods to MongoStatement

model/MySQLiStatement.php

@@ -117,6 +117,18 @@ class MySQLiStatement extends DbStatement
     {
         return $this->result->fetch_object($class);
     }
+
+    /**
+     * @return array
+     */
+    public function fetchPairs()
+    {
+        $data = array();
+        while ($row = $this->fetch(Db::FETCH_NUM)) {
+            $data[$row[0]] = $row[1];
+        }
+        return $data;
+    }
     
     public function close()
     {