Question

我是PHP的新手。我正在创建一个login.php页面。我已经在MySQL数据库中创建了一个表。数据库名称：学校表名：用户

我保存了username = admin和pass= 123

我现在正在尝试连接数据库并尝试在访问页面之前验证数据库中的输入信息＆＃34; admin.php＆＃34;

<?php
error_reporting(E_ERROR);
global $link;

$servername='localhost';
$dbname='school';
$dbusername='root';
$dbpassword='';
$table_Name="users";

$link = mysql_connect($servername,$dbusername,$dbpassword);

if (!$link) {
die('Could not connect: ' . mysql_error());
}
else 
{
mysql_select_db($dbname,$link) or die ("could not open db".mysql_error());
}

?>

从此代码获取输入数据

<?php
    $my_user = $_POST['user'];
    $my_password = $_POST['password'];
?>

尝试这个

 $signin = mysql_query( "SELECT FROM users where username = &my_user" )
 or die("SELECT Error:     ".mysql_error()); $num_rows = mysql_num_rows($signin);

现在请用代码解释如何连接数据库并验证信息，如果正确，页面应该重定向到admin.php页面

Answer 1

这会将表单信息插入数据库：

$insert="INSERT INTO `users`(`user`,`password`) VALUES ('$my_user','$my_password') ";
$query=mysql_query($insert,$link);

这将从数据库中选择信息：

$result=mysql_query('SELECT * FROM users WHERE username='$my_user' AND password='$my_password'");
$sql1=mysql_query($result,$link);

Answer 2

if(mysql_num_rows(mysql_query("select * from users where username='$my_user' and pass='$my_password'"))>0) {

    header('Location:admin.php');
} else {
    echo " < b > Incorrect username or password<\b>";
}

Answer 3

    <?php

    if (isset($_POST)) {

    $my_user = $_POST['user'];
    $my_password = $_POST['password'];

    $con=mysql_connect("localhost","root","");
    if(!$con)
    {
        die("Database is not connected");
    }
    mysql_select_db("school",$con);
    $query="select * from users where username=$my_user and pass=$my_password";
    $res=mysql_query($query);
    if(mysql_num_rows($res) > 0)
        header('Location:admin.php');  // redirect to home page
    else
        echo 'Not found';   // can show some validation err
}

Answer 4

<?php
include('conn.php');
if (isset($_POST['submit'])){
$UserName=$_POST['user'];
$PassWord=$_POST['pass'];

$sql = "SELECT username,pass from login WHERE username='$UserName'and password='$PassWord'";

$retval = mysql_query($sql);
if(! $retval )
{
  die('Could not get data: ' . mysql_error());
}
while($row = mysql_fetch_array($retval, MYSQL_ASSOC))
{

if (($row['username']==$Username)and($row['pass']==$Password)){

 header("location:admin.php");
                        }

 } 
}
echo "Invalid User Name and Password\n";

?>

Answer 5

开始使用PDO进行数据库连接。我没有对此进行测试，但应该让您深入了解该怎么做。

的config.php

<?php
define('DB_TYPE', 'mysql');
define('DB_HOST', 'localhost');
define('DB_NAME', 'school');
define('DB_USER', 'root');
define('DB_PASS', '');
?>

的functions.php

<?php 
function validate_user_creds() {
    try
{
  $pdo = new PDO(DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME.', '.DB_USER.', '.DB_PASS);
  $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

  header('Location: admin.php');
  exit();
}
catch (PDOException $e)
{
  $error = 'Unable to connect to the database server.';
  include 'error.html.php';
  exit();
}
}
?>

的login.php

<?php
require 'config.php';
require 'functions.php';

if ($_POST['user'] === DB_NAME && $_POST['password'] === DB_PASS) {
    validate_user_creds();
}

?>

Answer 6

在PHP中访问数据库时，将PDO与预准备语句一起使用，因为它有助于防止SQL注入。看看http://php.net/manual/en/intro.pdo.php。

编辑：韦恩的回答令人困惑。在login.php中，他通过将用户的名称与数据库名称和用户密码与数据库密码进行比较来验证管理员。我不推荐它，它与你发布的内容没什么关系。

我和PatrickB的答案一起去。

Answer 7

通常使用mysql（不建议使用！）

<?php

error_reporting(E_ERROR);

$error = false;
if(isset($_POST['login']))
{
    $servername = 'localhost';
    $dbname     = 'school';
    $dbusername = 'root';
    $dbpassword = '';
    $table_Name = 'users';

    $link = mysql_connect($servername, $dbusername, $dbpassword) or die('Could not connect: ' . mysql_error());

    mysql_select_db($dbname, $link) or die ('could not open db' . mysql_error());

    $my_user = $_POST['user'];
    $my_password = $_POST['password'];

    $signin = mysql_query("SELECT * FROM `users` WHERE `username` = '" . mysql_real_escape_string($my_user) . "' AND `password` = '" . mysql_real_escape_string($my_password) . "' LIMIT 1;")
              or die('SELECT Error: '.mysql_error());
    $num_rows = mysql_num_rows($signin);

    mysql_close($link);

    if($num_rows)
    {
        header('Location: admin.php');
    }
    else
    {
        $error = 'Unknown login!';
    }
}

?><html><head><title>Login</title></head><body>
    <form action="#" method="post">
        <?php if($error !== false) { echo '<p>' . $error . '</p>'; } ?>
        <input name="user" type="text" size="255" />
        <input name="password" type="text" size="255" />
        <button type="submit" name="login">Login</button>
    </form>
</body></html>

PDO / MySQLi

<?php

error_reporting(E_ERROR);

$error = false;
if(isset($_POST['login']))
{
    $servername = 'localhost';
    $dbname     = 'school';
    $dbusername = 'root';
    $dbpassword = '';
    $table_Name = 'users';

    $link = new mysqli($servername, $dbusername, $dbpassword, $dbname);

    if (mysqli_connect_errno())
    {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }

    $my_user = $_POST['user'];
    $my_password = $_POST['password'];

    if(!($signin = $link->prepare('SELECT * FROM `users` WHERE `username` = ? AND `password` = ? LIMIT 1;')))
    {
        printf("Select Error: %s\n", $link->error);
        exit();
    }

    $signin->bind_param('ss', $my_user, $my_password);
    if($signin->execute())
    {
        $signin->store_result();
        $num_rows = $signin->num_rows;

        if($num_rows)
        {
            header('Location: admin.php');
        }
        else
        {
            $error = 'Unknown login!';
        }
    }

    $link->close();
}

?><html><head><title>Login</title></head><body>
    <form action="#" method="post">
        <?php if($error !== false) { echo '<p>' . $error . '</p>'; } ?>
        <input name="user" type="text" size="255" />
        <input name="password" type="text" size="255" />
        <button type="submit" name="login">Login</button>
    </form>
</body></html>

PHP登录并连接到MySql

7 个答案: