PHP verify login username and password-PHP Tutorial-php.cn

PHP verify login username and password

韦小宝

Release： 2023-03-17 17:22:01

Original

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This article tells you how to use PHP to verify user names and passwords. It explains in detail howPHPconnects to the databaseand how to query data from the database. And verified, I hope it can help everyone learn PHP.

Login page

login.html Responsible for collecting login information filled in by users

<html>  
<head>用户登录</head>  
<form name="LoginForm" method="post" action="login.php" onSubmit="return InputCheck(this)">  
<p>  
<label for="username" class="label">用户名:</label>  
<input id="username" name="username" type="text" class="input" />  
<p/>  
<p>  
<label for="password" class="label">密 码:</label>  
<input id="password" name="password" type="password" class="input" />  
<p/>  
<p>  
<input type="submit" name="submit" value="  确 定  " class="left" />  
</p>  
</form>  
</html>

Copy after login

<?php  
//登录  
if(!isset($_POST[&#39;submit&#39;])){  
    exit(&#39;非法访问!&#39;);  
}  
$username = htmlspecialchars($_POST[&#39;username&#39;]);  
$password = MD5($_POST[&#39;password&#39;]);  
  
//包含数据库连接文件  
include(&#39;conn.php&#39;);  
//检测用户名及密码是否正确  
$check_query = mysql_query("select userid from user_list where username=&#39;$username&#39; and password=&#39;$password&#39; limit 1");  
if($result = mysql_fetch_array($check_query)){  
    //登录成功  
    session_start();  
    $_SESSION[&#39;username&#39;] = $username;  
    $_SESSION[&#39;userid&#39;] = $result[&#39;userid&#39;];  
    echo $username,&#39; 欢迎你！进入 <a href="my.php">用户中心</a><br />&#39;;  
    echo &#39;点击此处 <a href="login.php?action=logout">注销</a> 登录！<br />&#39;;  
    exit;  
} else {  
    exit(&#39;登录失败！点击此处 <a href="javascript:history.back(-1);">返回</a> 重试&#39;);  
}  
  
  
  
//注销登录  
if($_GET[&#39;action&#39;] == "logout"){  
    unset($_SESSION[&#39;userid&#39;]);  
    unset($_SESSION[&#39;username&#39;]);  
    echo &#39;注销登录成功！点击此处 <a href="login.html">登录</a>&#39;;  
    exit;  
}  
  
?>

Copy after login

User Center
my.php is the user center, used as a user login test.

<?php  
session_start();  
  
//检测是否登录，若没登录则转向登录界面  
if(!isset($_SESSION[&#39;userid&#39;])){  
    header("Location:login.html");  
    exit();  
}  
//包含数据库连接文件  
include(&#39;conn.php&#39;);  
$userid = $_SESSION[&#39;userid&#39;];  
$username = $_SESSION[&#39;username&#39;];  
$user_query = mysql_query("select * from user_list where userid = &#39;$userid&#39; limit 1");  
$row = mysql_fetch_array($user_query);  
echo &#39;用户信息：<br />&#39;;  
echo &#39;用户ID：&#39;,$userid,&#39;<br />&#39;;  
echo &#39;用户名：&#39;,$username,&#39;<br />&#39;;  
echo &#39;<a href="login.php?action=logout">注销</a> 登录<br />&#39;;  
?>

Copy after login

conn.php, used to connect to the database

<?php   
  
 $conn = mysql_connect("127.0.0.1","root","") or die("数据库链接错误".mysql_error());  
 mysql_select_db("info_db",$conn) or die("数据库访问错误".mysql_error());  
 mysql_query("set names gb2312");  
?>

Copy after login

The above is all the content of this chapter, I hope it will be helpful to everyone!

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