mysqli_stmt_prepare（）不插入数据

Question

我对PHP和MySQL相当陌生。我正在尝试在表单提交后插入数据。

mysqli_stmt_prepare（）不起作用，我知道它很简单，但是我无法弄清楚。当我在上一页中单击“提交”时，它进入此页面，但没有将字段输入数据库。

<?php
    include_once("../core/database/connection.php");

    $firstName = $_POST["firstName"];
    $lastName = $_POST["lastName"];
    $email = $_POST["email"];
    $userName = $_POST["userName"];
    $password = password_hash($_POST["password"], PASSWORD_DEFAULT);

    $sql = "INSERT INTO users (firstName, lastName, email, userName, password) VALUES (?, ?, ?, ?, ?);";

    $post_stmt = mysqli_stmt_init($connect);

    if(mysqli_stmt_prepare($post_stmt, $sql))
    {
        mysqli_stmt_bind_param($post_stmt, "sssss", $firstName, $lastName, $email, $userName, $password);
        mysqli_stmt_execute($post_stmt);
        echo "You have been successfully registered!";     
    }
    else
    {
        die('Error with execute: ' . htmlspecialchars($post_stmt->error));
    }

?>