我正在使用 000webhost 到我的 android 登錄/注冊(cè)應(yīng)用程序，當(dāng)輸入數(shù)據(jù)時(shí)，所有列都填充到數(shù)據(jù)庫(kù)中，除了用戶名它變成零并且沒(méi)有錯(cuò)誤注冊(cè).php<?php    $name = $_POST["name"];    $age = $_POST["age"];    $username = $_POST["username"];    $password = $_POST["password"];    $statement = mysqli_prepare($con, "INSERT INTO user (name, username, age, password) VALUES (?, ?, ?, ?)");    mysqli_stmt_bind_param($statement, "siss", $name, $username, $age, $password);    mysqli_stmt_execute($statement);    $response = array();    $response["success"] = true;      echo json_encode($response);?>登錄.php    $username = $_POST["username"];    $password = $_POST["password"];    $statement = mysqli_prepare($con, "SELECT * FROM user WHERE username = ? AND password = ?");    mysqli_stmt_bind_param($statement, "ss", $username, $password);    mysqli_stmt_execute($statement);    mysqli_stmt_store_result($statement);    mysqli_stmt_bind_result($statement, $userID, $name, $age, $username, $password);    $response = array();    $response["success"] = false;      while(mysqli_stmt_fetch($statement)){        $response["success"] = true;          $response["name"] = $name;        $response["age"] = $age;        $response["username"] = $username;        $response["password"] = $password;    }    echo json_encode($response);?>