What is the reason why the connection between mysql and php fails?

Causes and solutions for failed connection between mysql and php: 1. The MySQL server cannot be accessed. Use the ping command to check whether the MySQL server can be accessed; 2. The MySQL server port is blocked or occupied. When connecting to the MySQL server The correct port must be used; 3. The MySQL username or password is incorrect, and you must confirm that the username and password used are correct; 4. MySQL refuses the connection, check whether the configuration is correct in the MySQL configuration file; 5. Code, Grammatical errors.

Operating system for this tutorial: Windows 10 system, PHP version 8.1.3, Dell G3 computer.

When using PHP to connect to MySQL, sometimes the connection fails. Why is this?

Causes and solutions for failed connection between mysql and php

MySQL server cannot be accessed

First, we need to check MySQL Whether the server can be accessed. Maybe your MySQL server is running, but it cannot connect via the network. Open a command line prompt and try to use the ping command to check if the MySQL server is accessible. If you get a "request timed out" or "host not found" result, it's likely because the server is unreachable on the network.

MySQL server port is blocked or occupied

When connecting to the MySQL server, you must use the correct port. If the port is occupied or disabled by the firewall, then you Will not be able to connect to the MySQL server. You can use the netstat command to list which ports are in use. If the port used by the MySQL server is not listed, it may be because the port is occupied or blocked.

MySQL username or password is incorrect

Usually, another reason why you cannot connect to the MySQL database is that the username or password is incorrect. We need to confirm that the username and password used are correct. This information may be used in the PHP file, the MySQL configuration file, or directly entered into the MySQL command line.

MySQL refuses connection

The MySQL server may refuse the connection. This will happen if the max_connections or timeout value of the MySQL server is too low or there are not enough resources. . We need to check whether these configurations are correct in the MySQL configuration file and try to change them.

An error occurs when PHP connects to MySQL

Finally, an error may occur when PHP connects to MySQL. If there are code errors, syntax errors or variable problems in your PHP file , then you may not be able to connect to the MySQL database.

When any problems occur when connecting to MySQL, we need to troubleshoot these problems one by one and finally solve them. We need to find the problems and resolve them as quickly as possible to ensure that our application can connect to the MySQL database properly.

What are the tools for building a PHP development environment?

1. phpStudy is the most commonly used development environment for novices to get started.

2. WampServer, WampServer is also as simple to operate as phpStudy and is more friendly to novices.

3. XAMPP, XAMPP (Apache MySQL PHP PERL) is a powerful website building integration software package.

4. MAMP, MAMP is divided into two types: MAMP and MAMP Pro for Mac.

5. Pagoda Panel, Pagoda Panel is a server management software that supports Windows and Linux systems.

6. UPUPW, UPUPW is currently the most distinctive web server PHP suite under the Windows platform.

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