Question

我需要检查用户名是否被占用，如果是，它将不允许用户注册它将它们重定向到注册页面我应该在哪里添加脚本以检查用户名是否已被删除？或者我在哪里可以得到一个脚本继承我的剧本我有什么安慰。

 <?php

// Check if he wants to register:
if (!empty($_POST[username]))
{
// Check if passwords match.
if ($_POST[password] != $_POST[password2])
    exit("Error - Passwords don't match. Please go back and try again.");

// Assign some variables.
$date = time (" d - m - Y ");
$ip = $_SERVER[REMOTE_ADDR];

require_once("connect.php");

// Register him.
$query = mysql_query("INSERT INTO members 
(username, fname, email, password, date, ip)
VALUES      ('$_POST[username]','$_POST[fname]','$_POST[email]','$_POST[password]','$date','$ip')")
or die ("Error - Couldn't register user.");

echo "Welcome $_POST[username]! You've been successfully reigstered!<br />
    You Will Be Redirected To Our Home Page Where U Can Login ";
exit();
}

?>

Answer 1

您需要先检查您的用户名是否存在：

SELECT count(1) FROM members WHERE username = '$_POST[username]'

然后如果结果是＆gt; 0您抛出User already exists错误。

Answer 2

我更新了您的代码，我可能会检查是否采用了用户名。像其他人一样说读sql注入攻击并保护自己。

<?php

// Check if he wants to register:
if (!empty($_POST[username])) {
// Check if passwords match.
    if ($_POST[password] != $_POST[password2])
        exit("Error - Passwords don't match. Please go back and try again.");

// Assign some variables.
    $date = time(" d - m - Y ");
    $ip = $_SERVER[REMOTE_ADDR];

    require_once("connect.php");

    // CHEK IF USERNAME IS VALID
    if (someFunctionThatChecksIfUsernameIsTaken($_POST['username'])) {
        // Register him.
        $query = mysql_query("INSERT INTO members 
        (username, fname, email, password, date, ip)
        VALUES      ('$_POST[username]','$_POST[fname]','$_POST[email]','$_POST[password]','$date','$ip')")
                or die("Error - Couldn't register user.");

        echo "Welcome $_POST[username]! You've been successfully reigstered!<br />
        You Will Be Redirected To Our Home Page Where U Can Login ";
        exit();
    } else {
        // redirect him back to the page and tell the user that the username is taken
    }
}
?>

Answer 3

我对您的代码进行了一些更改，以使其正常工作并进行清理。

<?php
// Check if he wants to register
// - Make sure that param exists
// - Check length 
if (isset($_POST['username']) && strlen($_POST['username']) > 0) {

    // Check if passwords match.
    // - Make sure that params exist
    // - Check length 
    // - Check matching
    if (!isset($_POST['password']) || 
        !isset($_POST['password2']) ||
        strlen($_POST['password']) === 0 || 
        $_POST['password'] !== $_POST['password2']) {
           die("Error - Passwords don't match. Please go back and try again.");
    }

    require_once("connect.php");

    // Set array of params
    $fields = array(
        'username' => $_POST['username'],
        'fname' => isset($_POST['fname']) ? $_POST['fname'] : '',
        'email' => isset($_POST['email']) ? $_POST['email'] : '',
        'password' => $_POST['password'],
        'date' => date("d-m-Y"),
        'ip' => $_SERVER[REMOTE_ADDR]
    );

    // Escape fields agains sql injection
    $fields = array_map('mysql_real_escape_string', $fields);

    // Check if member exists
    $exists = mysql_num_rows(mysql_query("SELECT * FROM members WHERE username='" . $fields['username'] . "'"));
    if ($exists === 0) {

        // Insert member in DB
        if (mysql_query("INSERT INTO `members` (`" . implode('`,`', array_keys($fields)) . "`) VALUES ('" . implode("','", array_values($fields)) . "')") !== false) {
            echo "Welcome" . $_POST['username'] . "! You've been successfully reigstered!<br />
            You Will Be Redirected To Our Home Page Where U Can Login ";
            exit();
        } else {
            die("Error - Couldn't register user.");
        }
    } else {
        die("Error - Member exists!");
    }
}
?>

检查是否已使用用户名

3 个答案: