React+PHP交互问题：登录后无法通过Axios获取用户数据

前端采用React开发，尝试通过axios.get从PHP后端获取已登录用户数据，逻辑为：若后端无数据返回则跳转至登录页。但目前后端处理文件无返回值，导致用户被强制跳回登录页。

已尝试以下操作但未解决：

• 配置会话（Session）
• 将$_SESSION[]替换为$_POST[]
• 添加错误报告代码：

error_reporting(E_ALL);
ini_set('display_errors','1');

上述错误报告代码未生效，且无任何错误信息显示。Postman测试结果：

• GET请求返回空内容
• 使用x-www-form-urlencoded格式发送POST请求时，返回400错误，提示需填写所有字段

相关代码片段 #

登录接口（PHP） #

$db = _db();

try {

    $q=$db->prepare("SELECT * FROM users WHERE email = :email");
    $q->bindValue(":email", $_POST["email"]);
    $q->execute();
    $row = $q->fetch();

    if(!empty($row)){

        if (password_verify($_POST["password"], $row["password"])) {

            $user = array(
                "user_id" => $row["user_id"],
                "first_name" => $row["first_name"],
                "last_name" => $row["last_name"],
                "email" => $row["email"],
                "company" => $row["company"],
                "phone_number" => $row["phone_number"],
                "verified" => $row["verified"],
                "token" => $row["token"],
            );


            header("Content-type: application/x-www-form-urlencoded");
            http_response_code(200);
            echo json_encode($user);
            exit();

        } else {
            header("Content-type: application/x-www-form-urlencoded");
            http_response_code(400);
            echo json_encode("Wrong email or password");
            exit();
        }
        
        } else {
            header("Content-type: application/x-www-form-urlencoded");
            http_response_code(400);
            echo json_encode("User does not exist");
            exit();
    
        }

注册接口（PHP）- 配置$_SESSION实现验证后跳转仪表盘 #

$q=$db->prepare("INSERT INTO users(user_id, first_name, last_name, company, email,     phone_number, password, forgot_password, token, verified) VALUES(:user_id, :first_name, :last_name, :company, :email, :phone_number, :password, :forgot_password, :token, :verified)");
$q->bindValue(":user_id", null);
$q->bindValue(":first_name", $firstName);
$q->bindValue(":last_name", $lastName);
$q->bindValue(":company", $company);
$q->bindValue(":email", $email);
$q->bindValue(":phone_number", $phoneNumber);
$q->bindValue(":password", $passwordHash);
$q->bindValue(":forgot_password", $forgotPass);
$q->bindValue(":token", $token);
$q->bindValue(":verified", false);
$q->execute();

$user_id = $db->lastInsertId();

$to_email = $email;
$subject = "Email subject";
$message = "Click on the following link to verify your account:
    <a href='http://localhost/api/confirm_account.php?token=$token'>Confirm your account</a>";

require_once(__DIR__."/emailVerification/send_email.php");

$user = array(
    "user_id" => $_SESSION["user_id"] = $row["user_id"],
    "first_name" => $_SESSION["first_name"] = $row["first_name"],
    "last_name" => $_SESSION["last_name"] = $row["last_name"],
    "email" => $_SESSION["email"] = $row["email"],
    "company" => $_SESSION["company"] = $row["company"],
    "phone_number" => $_SESSION["phone_number"] = $row["phone_number"],
    "verified" => $_SESSION["verified"] = $row["verified"],
    "token" => $_SESSION["token"] = $row["token"],
);


header("Content-type: application/json");
http_response_code(200);
echo json_encode($user);
exit();
}
}

前端POST/GET请求处理（React） #

const handleLogInSubmit = (event) => {
    event.preventDefault();

    axios
      .post("http://localhost/api/login.php", {
        email: userInput.email,
        password: userInput.password,
      })
      .then((response) => {
        if (response.data) {
          navigate("/dashboard");
        } else {
          setErrorMessage("Login failed, try again");
        }
      })


 useEffect(() => {

    axios.get("http://localhost/api/login.php")
    .then((response) => {
      if(response.data){
        setUser(response.data);
        console.log(response.data)
      } else {
        console.log(response)
        navigate("/login");
      }
    });
}, [navigate]);

更新 #

已定位部分问题，但仍存在异常：显示“登录成功”后会被自动跳转回登录页。经排查，原因是axios.get请求无数据返回，仅axios.post请求能正常获取用户数据：

• POST请求登录：正常返回用户数据
• GET请求登录：返回空内容

内容的提问来源于stack exchange，提问作者meii18