AJAX Database
AJAX Database （AJAX数据库）
Introduction
Introduction （简介）
In this article, we will delve into the world of PHP, Ajax, and databases. Our aim is to provide a comprehensive guide on how to use PHP, Ajax, and databases to create dynamic web pages that can improve user experience and engagement. （在本文中，我们将深入探讨PHP、AJAX和数据库的世界。我们的目标是提供有关如何使用PHP、AJAX和数据库创建动态网页的全面指南，以提高用户体验和参与度。）
What is PHP?
What is PHP? （什么是PHP ？）
PHP is a server-side scripting language that is used to develop web applications. PHP is easy to learn and is compatible with various operating systems such as Linux, macOS, and Windows. PHP has a wide range of applications, from developing web pages to creating standalone desktop applications. （PHP是一种服务器端脚本语言，用于开发Web应用程序。PHP易于学习，与Linux、macOS和Windows等各种操作系统兼容。PHP具有广泛的应用程序，从开发网页到创建独立的桌面应用程序。）
What is Ajax?
What is Ajax? （什么是AJAX ？）
Ajax is a technique used in web development that enables web pages to be updated asynchronously without the need to reload the entire page. Ajax allows for the creation of dynamic web pages that can respond to user input in real-time. （Ajax是一种用于Web开发的技术，它使网页能够异步更新，而无需重新加载整个页面。Ajax允许创建可以实时响应用户输入的动态网页。）
What is a Database?
What is a Database? （什么是数据库？）
A database is a structured collection of data that can be accessed, managed, and updated. Databases are used in web development to store data that can be queried and manipulated to provide dynamic content to users. （数据库是可以访问、管理和更新的结构化数据集合。数据库用于Web开发，以存储可以查询和操作的数据，为用户提供动态内容。）
Using PHP, Ajax, and Databases to Create Dynamic Web Pages
Using PHP, Ajax, and Databases to Create Dynamic Web Pages （使用PHP、AJAX和数据库创建动态网页）
PHP, Ajax, and databases can be used together to create dynamic web pages that can provide a rich user experience. To achieve this, you need to follow the following steps:
Establish a connection to the database using PHPRetrieve data from the database using PHPUse Ajax to update the web page with the retrieved data （使用PHP从数据库中检索数据建立与数据库的连接使用PHPUse AJAX使用检索到的数据更新网页）
Establishing a Connection to the Database
To establish a connection to the database, you need to use PHP’s built-in function, mysqli_connect(). This function takes in the database host name, username, password, and database name as arguments. Once the connection is established, you can execute SQL queries to manipulate the data in the database. （要建立与数据库的连接，需要使用PHP的内置函数mysqli_connect ()。此函数将数据库主机名、用户名、密码和数据库名作为参数。建立连接后，您可以执行SQL查询来操作数据库中的数据。）
sequenceDiagram participant User （参与者用户） participant Web Server （参与者Web服务器） participant Database Server （participant数据库服务器） User-»Web Server: Sends HTTP Request Web Server-»Database Server: Establishes Connection Database Server-»Web Server: Sends Data Web Server-»User: Sends HTTP Response
Retrieving Data from the Database
To retrieve data from the database, you need to use SQL queries. SQL queries can be executed using the mysqli_query() function in PHP. The result of the query is returned as a result set that can be iterated over to retrieve the individual rows of data. （要从数据库检索数据，您需要使用SQL查询。SQL查询可以使用PHP中的mysqli_query ()函数执行。查询的结果作为结果集返回，可以迭代以检索单个数据行。）
Using Ajax to Update the Web Page
Once you have retrieved the data from the database, you can use Ajax to update the web page with the retrieved data. Ajax allows you to update a portion of the web page without having to reload the entire page. To achieve this, you need to create an XMLHttpRequest object in JavaScript and send a request to the server. Once the server sends back the response, you can update the web page with the retrieved data. （从数据库检索数据后，可以使用AJAX使用检索到的数据更新网页。Ajax允许您更新网页的一部分，而无需重新加载整个页面。为此，需要在JavaScript中创建XMLHttpRequest对象，并向服务器发送请求。服务器发送回响应后，您可以使用检索到的数据更新网页。）
Conclusion
Conclusion （小结）
PHP, Ajax, and databases can be used together to create dynamic web pages that can provide a rich user experience. In this article, we have provided a comprehensive guide on how to use PHP, Ajax, and databases to create dynamic web pages. By following the steps outlined in this article, you can create web pages that can outrank the existing article on w3schools.com/php/php_ajax_database.asp in Google search results.