Question

我正在创建一个用户重定向的代码，具体取决于他们的用户类型

我尝试过if，else语句，但是有一些错误 “ mysqli_stmt_bind_param（）：类型定义字符串中的元素数量与绑定变量的数量不匹配”

<?php
// Initialize the session
session_start();

// Include config file
require_once "config.php";

// Check if the user is already logged in, if yes then redirect him to 
welcome page
if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){
  if($_SESSION["userType"] == "administrator"){
    header("location: index.php");
    exit;
  }else($_SESSION["userType"] == "user"){
    header("location: userpage.php");
    exit;
  }
}


// Define variables and initialize with empty values
$username = $password = $userType = "";
$username_err = $password_err = "";

// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){

    // Check if username is empty
    if(empty(trim($_POST["username"]))){
        $username_err = "Please enter username.";
    } else{
        $username = trim($_POST["username"]);
    }

    // Check if password is empty
    if(empty(trim($_POST["password"]))){
        $password_err = "Please enter your password.";
    } else{
        $password = trim($_POST["password"]);
    }

    // Validate credentials
    if(empty($username_err) && empty($password_err)){
        // Prepare a select statement
        $sql = "SELECT * FROM users WHERE username = ? and userType = ?";

        if($stmt = mysqli_prepare($link, $sql)){
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, "ss", $param_username);

            // Set parameters
            $param_username = $username;
            // Attempt to execute the prepared statement
            if(mysqli_stmt_execute($stmt)){
                // Store result
                mysqli_stmt_store_result($stmt);

                // Check if username exists, if yes then verify password
                if(mysqli_stmt_num_rows($stmt) == 1){
                    // Bind result variables
                    mysqli_stmt_bind_result($stmt, $id, $username,  
$hashed_password, $userType);
                    if(mysqli_stmt_fetch($stmt)){
                        if(password_verify($password, $hashed_password)){

                            // Password is correct, so start a new session
                            session_start();

                            // Store data in session variables
                            $_SESSION["loggedin"] = true;
                            $_SESSION["id"] = $id;
                            $_SESSION["username"] = $username;
                            $_SESSION["userType"] = $userType;

                        } else{
                            // Display an error message if password is not valid
                            $password_err = "The password you entered was incorrect.";
                        } 
                    }
                }else{
                    // Display an error message if username doesn't exist
                    $username_err = "No account found with that username.";
                }
            } else{
                 echo "Oops! Something went wrong. Please try again later.";
            }
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }

    // Close connection
    mysqli_close($link);
}
?>

我想看看如何根据用户类型重定向用户。

Answer 1

您错过了mysqli_stmt_bind_param（）上的一个参数

因此您的代码应为：

mysqli_stmt_bind_result($stmt, 'ss', $param_username, $user_type);

请参见https://www.php.net/manual/en/mysqli-stmt.bind-param.php

用户帐户重定向

1 个答案: