Retrieval of database information through mysqli extension technology
Retrieval of database information through mysqli extension technology
In versions after PHP5.0, not only can the early MySQL database manipulation functions be used, but also You can also use mysqli extension technology to communicate with the MySQL database. The use of mysqli extension technology can not only call MySQL stored procedures and process MySQL transactions, but also make accessing the database more stable.
In the actual web project development process, it is often necessary to retrieve a large amount of information. In order to create a stable and fast query environment, this example will introduce how to use mysqli extension technology to achieve product information retrieval.
Technical Points
The key technology of this example is how to use mysqli technology to connect to the MySQL database and realize the retrieval of database information. Mysqli technology can use two programming ideas: object-oriented and process. This example uses the object-oriented programming method that is more popular today.
Using object-oriented programming to connect to the MySQL database will be implemented through PHP's predefined mysqli. The constructor of this class is described as follows.
The constructor of the mysqli class generally consists of the following 4 parameters:
hostname: The address or host name of the MySQL server.
username: The username of a user in the MySQL server.
userpwd: The user password corresponding to a user in the MySQL server.
databasename: The name of a database in the MySQL server. This parameter can be omitted. If this parameter is omitted, you need to use the mysqli member function select_db() to specify the database name.
The predefined instantiation form of mysqli is as follows:
new mysqli(string hostname, string username, string userpwd [,string databasename] );
Implementation process:
(1) Create a php File connection database and input form!
<form name="form1" action="1.php" method="post"> 请输入商品名称:<input type="text" name="name"> <input type="submit" value="查询"> </form> <?php header("Content-Type:text/html; charset=utf-8"); $link = new mysqli("localhost","root","root","php_cn");
(2) Determine whether the value of the submit button is empty. If the value is not empty, start the query. If the data information that the user wants to query is found, the data information will be displayed. Otherwise, it will prompt that the data was not found. Information, the specific code is as follows:
<?php if($_POST['Submit']) { header("Content-Type:text/html; charset=utf-8"); $link = mysqli_connect("localhost", "root", "root"); $conn = mysqli_select_db($link, "php_cn"); $name = $_POST['username']; $sql = "select * from `tb_book` where bookname like '%" . $name . "%'"; $result = mysqli_query($link, $sql); $res = mysqli_fetch_array($result, MYSQLI_ASSOC); if (!$res) { echo "<p align='center'>没有查到该商品!</p>"; } else { ?> <table width="600" height="15" border="0" align="center" cellspacing="0" cellpadding="0"> <tr> <td> </td> </tr> </table> <table width="600" height="50" border="0" align="center" cellspacing="0" cellpadding="0"> <tr> <td bgcolor="#0033FF"> <table width="600" height="50" border="0" align="center" cellspacing="1" cellpadding="0"> <tr> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'>书本名字</p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'>时间</p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'>价格</p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'>作者</p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'>出版社</p> </td> </tr> <?php do { ?> <tr> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'><?php echo $res['bookname'];?></p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'><?php echo $res['data'];?></p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'><?php echo $res['price'];?></p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'><?php echo $res['maker'];?></p> </td> <td width="156" height="25" bgcolor="#A2D4F4"> <p align='center'><?php echo $res['publisher'];?></p> </td> </tr> <?php } while ($res = mysqli_fetch_array($result, MYSQLI_ASSOC)); ?> </table> </td> </tr> </table> <?php } } ?>
The results of the above code are as follows:
This is about the retrieval of mysqli extension technology to obtain database information. Partners can test it locally. We will continue to introduce the mysqli extension in the next article. For details, please read "How to use mysqli extension technology to view server connection error reports"!
【Related tutorial recommendations】
1. Relevant topic recommendations: "php operating mysql database"
2.【 MYSQL Online Free Video Tutorial】
3. Recommended related video courses: "Elementary MySQLi Extension Library Video Tutorial 》
The above is the detailed content of Retrieval of database information through mysqli extension technology. For more information, please follow other related articles on the PHP Chinese website!

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

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

Hot Article

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

Go language is an efficient, concise and easy-to-learn programming language. It is favored by developers because of its advantages in concurrent programming and network programming. In actual development, database operations are an indispensable part. This article will introduce how to use Go language to implement database addition, deletion, modification and query operations. In Go language, we usually use third-party libraries to operate databases, such as commonly used sql packages, gorm, etc. Here we take the sql package as an example to introduce how to implement the addition, deletion, modification and query operations of the database. Assume we are using a MySQL database.

Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps

Hibernate polymorphic mapping can map inherited classes to the database and provides the following mapping types: joined-subclass: Create a separate table for the subclass, including all columns of the parent class. table-per-class: Create a separate table for subclasses, containing only subclass-specific columns. union-subclass: similar to joined-subclass, but the parent class table unions all subclass columns.

How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())

To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.

HTML cannot read the database directly, but it can be achieved through JavaScript and AJAX. The steps include establishing a database connection, sending a query, processing the response, and updating the page. This article provides a practical example of using JavaScript, AJAX and PHP to read data from a MySQL database, showing how to dynamically display query results in an HTML page. This example uses XMLHttpRequest to establish a database connection, send a query and process the response, thereby filling data into page elements and realizing the function of HTML reading the database.

PHP is a back-end programming language widely used in website development. It has powerful database operation functions and is often used to interact with databases such as MySQL. However, due to the complexity of Chinese character encoding, problems often arise when dealing with Chinese garbled characters in the database. This article will introduce the skills and practices of PHP in handling Chinese garbled characters in databases, including common causes of garbled characters, solutions and specific code examples. Common reasons for garbled characters are incorrect database character set settings: the correct character set needs to be selected when creating the database, such as utf8 or u

Through the Go standard library database/sql package, you can connect to remote databases such as MySQL, PostgreSQL or SQLite: create a connection string containing database connection information. Use the sql.Open() function to open a database connection. Perform database operations such as SQL queries and insert operations. Use defer to close the database connection to release resources.
