PHP:帮助根据数据库中的 url 重定向重定向用户

Question

我一直在尝试制作一个用户登录页面，当用户登录时，该页面会根据用户 ID 将用户重定向到特定的 url。

更具体地说，假设在数据库中我有 4 行:id、username、password、redirect。成功登录后，它将转到用户的特定行，获取重定向 url，并将用户重定向到该 url。我已经制作了一个脚本，该脚本将根据数据库的重定向 url 重定向 url，但是当我向数据库添加更多用户时，它会卡住并且通常不显示任何内容或重定向到错误的 url。这是代码:

<?php 
$host="localhost"; // Host name 
$username="root"; // Mysql username 
$password=""; // Mysql password 
$db_name="test"; // Database name 
$tbl_name="members"; // Table name 

// Connect to server and select databse. 
mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB"); 

// username and password sent from form 
$myusername=$_POST['myusername']; 
$mypassword=$_POST['mypassword']; 

// To protect MySQL injection (more detail about MySQL injection) 
$myusername = stripslashes($myusername); 
$mypassword = stripslashes($mypassword); 
$myusername = mysql_real_escape_string($myusername); 
$mypassword = mysql_real_escape_string($mypassword); 
$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'"; 
$result=mysql_query($sql); 

// Mysql_num_row is counting table row 
$count=mysql_num_rows($result); 
// If result matched $myusername and $mypassword, table row must be 1 row 
if($count==1){ 
// Register $myusername, $mypassword and redirect to file"login_success.php" 
$_SESSION['username'] = $myusername; 
$_SESSION['password'] = $mypassword; 
$result = mysql_query("SELECT redirect FROM members"); 

while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) { 
   header("Location: " . $row['redirect']); 
} 
exit(); 
} 
else { 
echo "Wrong Username or Password"; 
} 
?> 

我非常感谢任何帮助、教程或批评。谢谢。 (也请在您的回答中进行描述我对网络开发仍然很陌生。;))

Answer 1

因为你只能重定向一个人一次，而且你已经从你的原始选择查询中获得了 redirect 值来检查用户名和密码匹配，我会将你的代码更改为这样的东西:

$sql = "SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'"; 
$result = mysql_query($sql); 

// Mysql_num_row is counting table row 
$count = mysql_num_rows($result); 

// If result matched $myusername and $mypassword, table row must be 1 row 
if($count == 1){ 
    // Register $myusername, $mypassword and redirect to file"login_success.php" 
    $_SESSION['username'] = $myusername; 
    $_SESSION['password'] = $mypassword; 

    $result = mysql_fetch_array($result); // get the result set from the query

    $redirect = trim($result['redirect']); // get the redirect column's value

    if ($redirect == '') {
        echo "No redirect value was set!";
    } else {
        header('Location: ' . $redirect);
        exit;
    }
} else { 
    echo "Wrong Username or Password"; 
}