How can PHP7 connect to the database
This article will introduce to you how to connect to the database in PHP7. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.
* The mysql
library has been abolished in PHP7, so you can only use mysqli
and PDO
mysqli object-oriented style
<?php $serve = 'localhost:3306'; $username = 'root'; $password = 'admin123'; $dbname = 'examples'; $mysqli = new Mysqli($serve,$username,$password,$dbname); if($mysqli->connect_error){ die('connect error:'.$mysqli->connect_errno); } $mysqli->set_charset('UTF-8'); // 设置数据库字符集 $result = $mysqli->query('select * from customers'); $data = $result->fetch_all(); // 从结果集中获取所有数据 print_r($data); ?>
mysqli process-oriented style
<?php $serve = 'localhost:3306'; $username = 'root'; $password = 'admin123'; $dbname = 'examples'; $link = mysqli_connect($serve,$username,$password,$dbname); mysqli_set_charset($link,'UTF-8'); // 设置数据库字符集 $result = mysqli_query($link,'select * from customers'); $data = mysqli_fetch_all($result); // 从结果集中获取所有数据 print_r($data); ?>
PDO connects to the database
<?php $serve = 'mysql:host=localhost:3306;dbname=examples;charset=utf8'; $username = 'root'; $password = 'admin123'; try{ // PDO连接数据库若错误则会抛出一个PDOException异常 $PDO = new PDO($serve,$username,$password); $result = $PDO->query('select * from customers'); $data = $result->fetchAll(PDO::FETCH_ASSOC); // PDO::FETCH_ASSOC表示将对应结果集中的每一行作为一个由列名索引的数组返回 print_r($data); } catch (PDOException $error){ echo 'connect failed:'.$error->getMessage(); } ?>
Use PDO or mysqli You can connect to mysql, but it is more recommended to use PDO to connect to the database, because PDO supports 12 different database drivers, mysqli only supports mysql, and PDO has higher performance
Recommended learning:php video tutorial
The above is the detailed content of How can PHP7 connect to the database. 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

AI Hentai Generator
Generate AI Hentai for free.

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



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.

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

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.

Using the database callback function in Golang can achieve: executing custom code after the specified database operation is completed. Add custom behavior through separate functions without writing additional code. Callback functions are available for insert, update, delete, and query operations. You must use the sql.Exec, sql.QueryRow, or sql.Query function to use the callback function.

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.

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

Use the DataAccessObjects (DAO) library in C++ to connect and operate the database, including establishing database connections, executing SQL queries, inserting new records and updating existing records. The specific steps are: 1. Include necessary library statements; 2. Open the database file; 3. Create a Recordset object to execute SQL queries or manipulate data; 4. Traverse the results or update records according to specific needs.
