Wordpress-Using wpdb to connect to a separate database

Below is the code to connect to a separate database in wordpress.

$mydb = new wpdb('username','password','database','localhost');
$rows = $mydb->get_results("select Name from my_table");
echo "
";
foreach ($rows as $obj) :
   echo "
".$obj->Name."
";
endforeach;
echo "
";