我基本上是在尝试用动态查询更新用户信息。一切都很好，但当我尝试执行查询时，它的返回总是false。

function updateUser($username, $email, $pass){

    $arr = [];
    $values = [];
    $params = [];

    if(isset($username))
    {
        array_push($arr, "userName = :username");
        array_push($values, $username);
        array_push($params, ":username");
    }
    if(isset($email))
    {
        array_push($arr, "userEmail = :email");
        array_push($values, $email);
        array_push($params, ":email");
    }
    if(isset($pass))
    {
        array_push($arr, "userPassword = :pass");
        array_push($values, $pass);
        array_push($params, ":pass");
    }

    $sql = "UPDATE users SET " . implode(", ", $arr) . " WHERE userId = :uId";
    $query = $db->prepare($sql);

    foreach ($params as $key) {
        foreach ($values as $value) {
            $query->bindValue($key, $value, PDO::PARAM_STR);
        }
    }

    $query->bindValue(":uId", $_SESSION["userId"]);

    if($query->execute() && $query->rowCount() > 0)
        return true;
    else
        return false // always false return
}

这是我的数组数据：