The SQLSTATE[HY000] [2002] error is a common issue encountered by developers working with MySQL databases and PHP. This error occurs when PHP is unable to connect to the MySQL server due to a DNS resolution issue. In this guide, we'll go through the steps to troubleshoot and fix this error.
Table of Contents
- Prerequisites
- Identifying the Issue
- Solutions
- 1. Check Your Database Connection Details
- 2. Check Your Hosts File
- 3. DNS Resolution Issue
- 4. Firewall Configuration
- FAQ
- Related Links
Prerequisites
Before diving into the solutions, make sure you have the following requirements met:
- A web server with PHP and MySQL installed.
- Access to your server (SSH or remote desktop).
Identifying the Issue
The SQLSTATE[HY000] [2002] error with the message "php_network_getaddresses: getaddrinfo failed: Name or service not known" indicates that PHP is unable to resolve the hostname of your MySQL server. This can be due to incorrect database connection details, issues with your hosts file, DNS resolution problems, or firewall configurations.
Solutions
1. Check Your Database Connection Details
First, ensure that your database connection details in your PHP script are correct. Double-check the hostname, username, password, and database name. The hostname should be either localhost, 127.0.0.1, or the domain name of your MySQL server.
<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
?>
2. Check Your Hosts File
The hosts file is used by the operating system to map hostnames to IP addresses. If there is an incorrect entry in the hosts file, it may cause the error. Check your hosts file and ensure that there is no incorrect entry for your MySQL server's hostname.
- On Linux and macOS, the hosts file is located at
/etc/hosts. - On Windows, the hosts file is located at
%SystemRoot%\System32\drivers\etc\hosts.
3. DNS Resolution Issue
If your MySQL server's hostname is a domain name, there might be issues with DNS resolution. You can try to resolve the domain manually using the following commands:
- On Linux and macOS, use the
digcommand:
dig your_mysql_server_domain_name
- On Windows, use the
nslookupcommand:
nslookup your_mysql_server_domain_name
If the domain name does not resolve correctly, check your DNS settings, or contact your DNS provider for assistance.
4. Firewall Configuration
Lastly, make sure that there are no firewall configurations blocking the connection between your PHP script and the MySQL server. Check both the server hosting your PHP script and the server hosting your MySQL database for any firewall rules that might be preventing the connection.
FAQ
Why am I receiving the SQLSTATE[HY000] [2002] error?
The SQLSTATE[HY000] [2002] error occurs when PHP is unable to connect to the MySQL server due to a DNS resolution issue. This can be caused by incorrect database connection details, issues with your hosts file, DNS resolution problems, or firewall configurations.
How can I check my database connection details?
You can check your database connection details in your PHP script. Ensure that the hostname, username, password, and database name are correct.
How do I check my hosts file for incorrect entries?
You can check your hosts file for incorrect entries by opening the file in a text editor. On Linux and macOS, the hosts file is located at /etc/hosts. On Windows, the hosts file is located at %SystemRoot%\System32\drivers\etc\hosts.
How do I resolve a domain name manually?
You can resolve a domain name manually using the dig command on Linux and macOS, or the nslookup command on Windows.
How can I check if a firewall is blocking the connection between my PHP script and the MySQL server?
You can check the firewall configurations on both the server hosting your PHP script and the server hosting your MySQL database. Look for any rules that might be preventing the connection.