search
HomeBackend DevelopmentPHP TutorialRelevant code analysis for php to implement login function

Naturally, I started with the simplest function. My first task was to perform a login operation, but it was not as simple as I thought.

1. The first thing is to connect and create the database.

I wrote this part in model.php

$userName='root';
$passWord='';
$host='localhost';
$dataBase='login';
//创建连接
$conn=mysqli_connect($host,$userName,$passWord,$dataBase);

2. To write the front-end page, in order to become proficient in the front-end framework, I used The layui framework makes the interface, and there is a js code in front of it to determine whether the username and password input is empty

<!DOCTYPE html>
<html lang="en">
<script src="layui.js";></script>
<link rel="stylesheet" href="layui.css" ;>
<head>
    <meta charset="UTF-8">
    <title>注册登录</title>
</head>
<script language=JavaScript>
    function InputCheck()
    {
        if (Login.username.value == "")
            {
             alert("请输入用户名!");
             Login.username.focus();
             return (false);
             }
        if (Login.password.value == "")
             {
               alert("请输入密码!");
               Login.password.focus();
            return (false);
             }
         }
</script>
<body style="background: #1E9FFF">
<p style="position: absolute; left: 50%; top: 50%;width: 500px; margin-left:-250px; margin-top: -200px">
    <p style="background: #FFFFFF; padding: 20px;border-radius: 4px;box-shadow: 5px 5px 20px #444444" >
        <p class="layui-form">
            <form action="login.php" method="post" name="Login" onsubmit="return InputCheck()">
                <p class="layui-form-item" style="color: gray">
                    <h2 id="注册登录系统">注册登录系统</h2>
                </p>
                <hr>
                <p class="layui-form-item">
                    <label class="layui-form-label">用户名</label>
                    <p class="layui-input-block">
                        <input type="text" name="username" id="username" placeholder="用户名" autocomplete="off" class="layui-input">
                    </p>
                </p>
                <p class="layui-form-item">
                    <label class="layui-form-label">密    码</label>
                    <p class="layui-input-block">
                        <input type="password" name="password" id="password" placeholder="密码" autocomplete="off" class="layui-input">
                    </p>
                </p>
                <p class="layui-form-item">
                    <p class="layui-input-block";>
                        <input type="submit" value="登录" class="layui-btn">
                        <input type="button" value="注册" class="layui-btn">
                    </p>
                </p>
            </form>
        </p>
    </p>
</p>
</body>
</html>

3.login.php is used to determine the correctness of the username and password. I read about this on the Internet There are many methods, all kinds of. Before I encountered any obstacles, I decided to use a simple form first, which is to use SQL statements to query the result set of user name and password. If the result set is empty, the user does not exist.

<?php
//数据库连接
require_once &#39;model.php&#39;;
//从登录页接受来的数据
$name=$_POST[&#39;username&#39;];
$pwd=$_POST[&#39;password&#39;];
$sql="select id,username,password from user where username=&#39;$name&#39; AND password=&#39;$pwd&#39;;";
$result=mysqli_query($conn,$sql);
$row=mysqli_num_rows($result);
if(!$row){
        echo "<script>alert(&#39;密码错误,请重新输入&#39;);location=&#39;login.html&#39;</script>";
    }
    else{
        echo "<script>alert(&#39;登录成功&#39;);location=&#39;123&#39;</script>";
    };

4. File directory

5. Effect



6. Summary

Overall it is not particularly difficult because the function is very simple. The next task is to add the registration function and verification code function.

This article explains the relevant code of php to implement the login function. For more related content, please pay attention to the php Chinese website.

Related recommendations:
Explanation of JavaScript-related content

Explanation of the basics of HTML

$.ajax php practical tutorial automatically loads more articles when you pull down the principle explanation

The above is the detailed content of Relevant code analysis for php to implement login function. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
What is the difference between absolute and idle session timeouts?What is the difference between absolute and idle session timeouts?May 03, 2025 am 12:21 AM

Absolute session timeout starts at the time of session creation, while an idle session timeout starts at the time of user's no operation. Absolute session timeout is suitable for scenarios where strict control of the session life cycle is required, such as financial applications; idle session timeout is suitable for applications that want users to keep their session active for a long time, such as social media.

What steps would you take if sessions aren't working on your server?What steps would you take if sessions aren't working on your server?May 03, 2025 am 12:19 AM

The server session failure can be solved through the following steps: 1. Check the server configuration to ensure that the session is set correctly. 2. Verify client cookies, confirm that the browser supports it and send it correctly. 3. Check session storage services, such as Redis, to ensure that they are running normally. 4. Review the application code to ensure the correct session logic. Through these steps, conversation problems can be effectively diagnosed and repaired and user experience can be improved.

What is the significance of the session_start() function?What is the significance of the session_start() function?May 03, 2025 am 12:18 AM

session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.

What is the importance of setting the httponly flag for session cookies?What is the importance of setting the httponly flag for session cookies?May 03, 2025 am 12:10 AM

Setting the httponly flag is crucial for session cookies because it can effectively prevent XSS attacks and protect user session information. Specifically, 1) the httponly flag prevents JavaScript from accessing cookies, 2) the flag can be set through setcookies and make_response in PHP and Flask, 3) Although it cannot be prevented from all attacks, it should be part of the overall security policy.

What problem do PHP sessions solve in web development?What problem do PHP sessions solve in web development?May 03, 2025 am 12:02 AM

PHPsessionssolvetheproblemofmaintainingstateacrossmultipleHTTPrequestsbystoringdataontheserverandassociatingitwithauniquesessionID.1)Theystoredataserver-side,typicallyinfilesordatabases,anduseasessionIDstoredinacookietoretrievedata.2)Sessionsenhances

What data can be stored in a PHP session?What data can be stored in a PHP session?May 02, 2025 am 12:17 AM

PHPsessionscanstorestrings,numbers,arrays,andobjects.1.Strings:textdatalikeusernames.2.Numbers:integersorfloatsforcounters.3.Arrays:listslikeshoppingcarts.4.Objects:complexstructuresthatareserialized.

How do you start a PHP session?How do you start a PHP session?May 02, 2025 am 12:16 AM

TostartaPHPsession,usesession_start()atthescript'sbeginning.1)Placeitbeforeanyoutputtosetthesessioncookie.2)Usesessionsforuserdatalikeloginstatusorshoppingcarts.3)RegeneratesessionIDstopreventfixationattacks.4)Considerusingadatabaseforsessionstoragei

What is session regeneration, and how does it improve security?What is session regeneration, and how does it improve security?May 02, 2025 am 12:15 AM

Session regeneration refers to generating a new session ID and invalidating the old ID when the user performs sensitive operations in case of session fixed attacks. The implementation steps include: 1. Detect sensitive operations, 2. Generate new session ID, 3. Destroy old session ID, 4. Update user-side session information.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

SublimeText3 Linux new version

SublimeText3 Linux new version

SublimeText3 Linux latest version

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools