Detailed explanation of the application of php session-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

Detailed explanation of the application of php session

墨辰丷

May 24, 2018 pm 04:33 PM

php session application

Detailed explanation of the application of php session

This article mainly introduces relevant information about the application of php session in detail. Friends in need can refer to

php session advanced application

Session is very important in web technology. Since the web page is a stateless connection program, the user's browsing status cannot be known. Through the session, the user's relevant information can be recorded for confirmation when the user submits a request to the web server again in this capacity.

For example: When a user browses an e-commerce website, if there is no session, the user needs to enter the account password every time he browses.

Related topic recommendations: php session (including pictures, texts, videos, cases)

1, Session temporary files

In the server, if all user sessions are saved in the temporary directory, the security and efficiency of the server will be reduced. Opening a site stored on the server will be very slow.

Using the PHP function session_save_path() function to store session temporary files can alleviate the problems of reduced server efficiency and slow site opening caused by the storage of temporary files.

The sample code is as follows:

<?php
$path ="./tmp/";    //设置session存储的路径
session_save_path($path);
session_start();
$_SESSION[&#39;userName&#39;]=true;
?>

Copy after login

Note

session_save_path() must be executed before session_start().

2, Session cache

Session cache temporarily stores the content in the web page to the Temporary INternet Files folder of the IE client, and the cache time can be set.

Session cache uses the session_cache_limiter() function, whose syntax is as follows:

string session_cache_limiter([string cache_limiter]);

Copy after login

The parameter cache_limiter is public or private. Colleagues session is not on the server side, but on the client side. Not shown on the server.

To set the cache time, use the function session_cache_expire(). The syntax is as follows:

int session_cache_expire([int new_cahche_expire]);

Copy after login

The parameter new_cahche_expire is the time number of the session cache, in minutes.

Note:

These two session functions must be executed before the session_start() function

Example of session cache page The code is as follows:

<?php

session_cache_limiter("private");
$cache_limit =session_cache_limiter();   //开启客户端缓存
echo "缓存限制为：".$cache_limit."\n";
session_cache_expire(30);
$cache_expire = session_cache_expire();  //设定客户端缓存时间
echo "客户端缓存时间为：".$cache_expire."分钟\n";
session_start();

?>

Copy after login

The running results are as follows:

Detailed explanation of the application of php session

##3, Session database storage

Session database storage in php is mainly implemented through the session_set_save_handler() function. The specific syntax is as follows:

bool session_set_save_handler(string open,string close,string read,string write,string destroy,string gc);

Detailed explanation of the application of php session

The six parameters (functions) are divided into packages below. After learning object-oriented programming, everyone will have a clearer understanding.

(1) Encapsulate the session_open() function, the code is as follows:

function _session_open($save_path,$session_name){
global $handle;
$handle =mysql_connect(&#39;localhost&#39;,&#39;root&#39;,&#39;root&#39;)or die(&#39;数据库连接失败！&#39;);
mysql_select_db(&#39;db_database11&#39;,$handle)or die(&#39;数据库不存在&#39;);
return(true);
}

Copy after login

(2) Encapsulate the session_close() function, the code is as follows:

function _session_close(){
global $handle;
mysql_close($handle);
return(true);
}

Copy after login

(3) Encapsulate the session_read() function, set the UNIX timestamp of the current time in the function, and search the Session business card and content based on $key. The code is as follows:

function _session_read($key){
golbal $handle;     //全局变量$handle 连接数据库
$time =time();     //设定当前时间
$sql ="select session_data from tb_session where session_key = &#39;$key&#39; and session_time>&#39;$time&#39;";
$result =mysql_query($ssql,$handle);
$row =mysql_fetch_array($result);
if($row){
return($row[&#39;session_data&#39;]);
}else{
return(false);
}
}

Copy after login

(4) Encapsulate the session_write() function. The function sets the expiration time of the Session and finds the name and content of the Session. If the query result is empty. Then insert the Session in the page into the database based on session_id, session_name, and expiration time. If the query result is not empty, modify the Session storage information in the database based on $key. The code is as follows:

function _session_write($key,$data){
global $handle;
$time = 60*60;
$lapse_time =time()+$time;   //得到UNIX时间戳
$sql = "select session_data from tb_session where session_key =&#39;$key&#39; and session_time>$lapse_time";
$result =mysql_query($sql,$handle);
if(mysql_num_rows($result)==0){  //没有结果
$sql ="insert into tb_session values(&#39;$key&#39;,&#39;$data&#39;,$lapse_time)";
$result =mysql_query($sql,$handle);
}else{
$sql ="update tb_session set session_key=&#39;$key&#39;,session_data =&#39;$data&#39;,session_time =$lapse_time where session_key =&#39;$key&#39;";
$result =mysql_query($sql,$handle);
}
return($result);
}

Copy after login

(5) Encapsulate session_destroy(), and delete Sessin in the database based on $key. The code is as follows:

function _session_destroy(){
global $handle;
$sql ="delete from tb_session where session_key =&#39;$key&#39;";
$result =mysql_query($sql,$handle);
}

Copy after login

(6) Encapsulate session_gc(), based on the Session expiration time Delete the expired Session. The sample code is as follows:

functin _session_gc($expiry_time){
global $handle;
$sql ="delete from tb_session where session_expiry_time<$expiry_time";
$result =mysql_query($sql,$handle);
return($result);
}

Copy after login

I will not run the specific code. I will demonstrate it to you when I finish learning object-oriented programming.

The above is the entire content of this article, I hope it will be helpful to everyone's study.

Related recommendations:

Detailed explanation of how to use session-cookie with php and codeigniter

Perfect Solve the problem of Session failure during ajax access

Detailed explanation of the method of storing PHPSession into the database/redis

The above is the detailed content of Detailed explanation of the application of php session. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website

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

Hot AI Tools

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress images for free

Clothoff.io

AI clothes remover

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)

1 months ago By 尊渡假赌尊渡假赌尊渡假赌

R.E.P.O. Best Graphic Settings

1 months ago By 尊渡假赌尊渡假赌尊渡假赌

Assassin's Creed Shadows: Seashell Riddle Solution

2 weeks ago By DDD

R.E.P.O. How to Fix Audio if You Can't Hear Anyone

1 months ago By 尊渡假赌尊渡假赌尊渡假赌

R.E.P.O. Chat Commands and How to Use Them

1 months ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Where is the login entrance for gmail email?

7539

CakePHP Tutorial

1380

What is the format of the account name of steam

win11 activation key permanent

nyt connections hints and answers

Related knowledge

PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

7 PHP Functions I Regret I Didn't Know Before Nov 13, 2024 am 09:42 AM

If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op

How do you parse and process HTML/XML in PHP? Feb 07, 2025 am 11:57 AM

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

PHP Program to Count Vowels in a String Feb 07, 2025 pm 12:12 PM

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? Apr 03, 2025 am 12:03 AM

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

See all articles