Question

我有一个登录表单执行以下操作：

它接受使用重定向登录消息注册的用户。
它告诉您是否需要注册您的用户名/密码不在系统中。

如果没有在用户名/密码表单中输入任何内容，它会重定向到具有敏感mysql数据的页面...如何添加一条向用户大喊大叫信息的php消息？

  if ($numrows != 0)
  {

    $user = mysql_fetch_assoc($query);
echo "Welcome,".$username. "you are being directed to the <a href=\"page.php\">.</a>";
    $_SESSION['username']= $user['username']; 
  }


  else
  {
    echo ("please reenter your username and password. If you don't have those, please <a href=\".php\">register.</a>");
  }

Answer 1

如何添加一条对用户大喊大叫的php消息信息？

这样的事情：

if( !isset( $_POST['username'] ) && !isset( $_POST['password'] ) ){
    // This won't show if you use a header redirect
    echo "YOU MUST ENTER A LOGIN";

    exit; // Halt execution if necessary
}

如果需要，为empty()添加一些检查。

或者，如果您正在使用会话/ cookie和某种User对象，请执行此操作：

if( $user == null || !$user->isConnected() ){
    // This won't show if you use a header redirect
    echo "YOU MUST ENTER A LOGIN";

    exit; // Halt execution if necessary
}

P.S：echo和exit可以合并为：

die("YOU MUST ENTER A LOGIN");

Answer 2

使用php标头功能将用户重定向到您想要的任何页面。您可以将它们发送回登录页面或新页面。

<击> http://www.w3schools.com/php/func_http_header.asp

http://php.net/manual/en/function.header.php

header('Location: http://www.example.com/');

您需要检查输入的表单值是否可以接受。因此，请检查它们是否存在于您的代码中，然后根据它将它们发送到适当的位置。

Answer 3

利用现有会话来保存您的错误。

<?php 
session_start();
$continue=true;
if(isset($_POST)){
    if(empty($_POST['username']) || strlen($_POST['username']) < 3){
        $_SESSION['error']['username']='You must fill in your username';
        $continue=false;
    }
    /*or if you use email as username
    if(empty($_POST['username']) || filter_var($_POST['username'], FILTER_VALIDATE_URL)==false){
        $_SESSION['error']['username']='You must fill in your username';
        $continue=false;
    }*/

    if(empty($_POST['password'])){
        $_SESSION['error']['password']='You must fill in your password';
        $continue=false;
    }
}else{
    $_SESSION['error']['nopost']='You must fill out the form';
    $continue=false;
}

if($continue===false){
    header('location: ./login.php');
    die();
}
  //do all the connect stuff...
  $username = mysql_real_escape_string($_POST['username']);
  $password = mysql_real_escape_string($_POST['password']);
  $sql = "SELECT * FROM members WHERE username='$username' && password='$password' LIMIT 1";

  if (mysql_num_rows(mysql_query($sql)==1)) {
    //log them in
    $_SESSION['loggedin']=true;
    header('location: ./members.php'); 
    //or whatever
    /*
    members.php would have a check for `$_SESSION['loggedin']==true` at the top
    else redirect them to login.php with another header()
    */
}else{
    $_SESSION['error']['username']='Wrong username or password';
    $_SESSION['loggedin']=false;
    header('location: ./index.php');
}
die();

?>

Answer 4

你可以这样做：

if(isset($_POST['button_name'])) {
    if(isset($_POST['username']) && $_POST['username'] != "") {
        if(isset($_POST['password']) && $_POST['password'] != "") {
            //Your code here
        } else {
            echo "You need to enter your password.";
        }
    } else {
        echo "You need to enter your username.";
    }
}

您需要添加提交表单的按钮的名称以及用户名和密码字段的名称。回声只是一个建议，你总是可以做其他事情。

Answer 5

检查访问者是否在任何数据库查询之前按下了提交按钮：

login.php

<?php 

if (!isset($_POST['Submit'])) {
  // No input, redirect to login.php with error code 1
  header("Location: index.php?error=1");
}      
else{
  // There is inout
  $username = $_POST['username'];
  $password = $_POST['password'];
  // Account for typecase here if necessary
  $sql = "SELECT * FROM members WHERE username = '$username' AND password = '$password'";

  if (mysql_num_rows(mysql_query($sql))) {
    // User is authenticated, redirect to private page
    header("Location: private.php");
  }
  else {
    // Wrong input, redirect to login.php with error code 2
    header("Location: index.php?error=2");
  }
}
?>

index.php

<?php
$errors[1] = 'Please type your usename and password';
$errors[2] = 'please verify your username and password';
?>

<form method="post" action="login.php">
  <p>
  <?php 
    if(isset($_GET['error']) && isset($errors[$_GET['error']])) 
      echo $errors[$_GET['error']], '</br>';
  ?>
  Username: <input type="text" name="username" /><br />
  Password: <input type="password" name="username" /><br />
  <input type="submit" name="submit" value="Let me in"/>
  </p>
</form>

强制用户将数据输入表单

5 个答案: