Getting Started with PHP - Basic Concepts

1. Concept
(1) Static website and dynamic website
Static website: a website that does not support data interaction (.html);
Dynamic website: a website that supports data interaction;
Technology to implement dynamic websites: ASP (.asp) , PHP (.php), .NET (.aspx), JAVA (.jsp);
(2) Client and server
The client sends a request (HTTP request) to the server, and the server will send the static resource (HTML code , pictures, js, css) are sent to the client, and the client parses the returned code through the browser to form the web page we see;
(3) Port and port number
Range: 0-65535, port numbers below 1024 are reserved For the system, port 80 is generally reserved for WEB servers, port 21 is reserved for FTP, and port 25 is reserved for mail servers;
Check whether the port number is occupied: enter netstat -ano on the command line;
(4) BS and CS
BS: Access the server through the browser;
CS: Access the server through the client;
(5) Site
When all materials related to the website are stored in a folder, the folder is called a site;
2. Apache
( 1) Installation of Apache
Language operation requires environmental support. Apache provides an environment for PHP operation. (IIS) can also be a PHP operating environment;
(2) Test server
Enter http://localhost in the address of the browser. If The browser displays it works!, which means the installation is successful;
(3) 127.0.0.1: local IP address;
(4) Apache server operations: start, shut down, restart;
(5) file directory
bin: Apache command folder;
conf: Apache’s configuration folder;
htdocs: Apache’s virtual directory;
3. PHP installation
(1) Chinese characters cannot appear in the installation path;
(2) After the installation is completed, the server (Apache) needs to be restarted;
(3) Test whether PHP is successfully installed
Create a new PHP page in the virtual directory with the following code: ;
Enter: http://localhost/ in the address bar of the browser File name.php;
If the PHP version information is displayed in the browser, it means that the PHP installation is successful;
(4) PHP directory structure
php.ini: PHP configuration file;
4. MySQL installation
(1) Database use To save data, common databases: MySQL, access, sqlite, SQL server, Oracle;
(2) MySQL directory structure
bin: MySQL command line folder;
my.ini: MySQL configuration folder;
mysqld.exe: MySQL server;
mysql.exe: MySQL client;
(3) When installing database software, you need to select the database software installation path and file saving path;
5. WAMP and LAMP
(1) WAMP: windows, Apache, MySQL , PHP integrated development environment;
(2) LAMP: Linux, Apache, MySQL, PHP integrated development environment;
6. Change the virtual directory
(1) Because the operation of PHP requires the support of Apache, the PHP directory must be informed to Apache. Configure the location of the PHP virtual directory in Apache's configuration file;
(2) Find documentroot in the httpd.conf (configuration file, case-insensitive) file in the Apache folder, and modify the path of the virtual directory (the target folder's path), modify the slash;
(3) Test: Enter http://localhost/ file name in the browser address bar, but the specified page cannot be opened because access permissions are not set for the changed directory;
(4) Site And virtual directory
Site: It is a folder to store web page materials;
Virtual directory: site + permissions;
Seven. Change the homepage
(1) DirectoryIndex: Find this word and add the file name.php;
Eight. Change the listening port
(1) listen: Find this word and modify the port number after listen;
(2) Browser request format: http://website:port number/filename.php, if the port number is 80, then the port number can be Omitted;
9. DNS resolution
(1) In the Internet, the IP address uniquely identifies a computer, but the IP address is inconvenient to remember. We use a domain name to correspond to an IP address;
(2) The client enters the domain name, first Will request the nearest DNS server (Domain name server domain name resolution system) to resolve the domain name into an IP address;
(3) The nearest DNS server is the local machine;
10. Virtual host
(1) One Apache supports multiple websites, from From the viewer's perspective, each website is an independent host, called a virtual host;
(2) Configuration
First, turn on the virtual host: Include conf/extra/httpd-vhosts.conf, open the comments;

The above has introduced PHP introductory learning - basic concepts, including aspects of content. I hope it will be helpful to friends who are interested in PHP tutorials.