$username_decoded = '<i>marco</i>';
$stmt = $this->db->prepare("SELECT * FROM foo WHERE username=:username");
$stmt->bindParam(':username',$username_decoded,PDO::PARAM_STR);
$stmt->execute();
$all_fetched = $stmt->fetchAll(PDO::FETCH_NUM);
print_r($all_fetched);
上面的代码给了我空数组。该用户名存在于数据库中。它出什么问题了?