PDOException: PDO::__construct(): php_network_getaddresses: getaddrinfo failed: no such host known

Question

I am new in PHP and when I am trying to connect my database with PHP it is showing error

Uncaught PDOException: PDO::__construct(): php_network_getaddresses: getaddrinfo failed: No such host is known. in C:\xampp\htdocs\sql_php\pdo.php:2 Stack trace: #0 C:\xampp\htdocs\sql_php\pdo.php(2): PDO->__construct('mysql:host=port...', 'Rohitash', 'rohitcodes') #1 {main} Next PDOException: SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: No such host is known. in C:\xampp\htdocs\sql_php\pdo.php:2 Stack trace: #0 C:\xampp\htdocs\sql_php\pdo.php(2): PDO->__construct('mysql:host=port...', 'Rohitash', 'rohitcodes') #1 {main} thrown in C:\xampp\htdocs\sql_php\pdo.php on line 2

what can be the possible causes for that.

what are you using for the `hostname`? – Professor Abronsius Sep 15 '18 at 06:56 — Professor Abronsius, Sep 15 '18 at 06:56

Your Common Sense · Answer 1 · 2022-12-17T05:23:30.050

The error means your PHP cannot find the host where MySQL server is supposed to be. Please check if hostname is correct.

Reading the error message attentively always helps. As you can see from the stack trace, namely the __construct('mysql:host=port...', part, the hostname used begins from the word "port", which doesn't seem to be a valid hostname. Try to use 127.0.0.1 if MySQL is located on the same computer or a correct hostname if it's on some other host.

Note that you should never do anything like try {...} catch(...) {echo "Connection failed: " . $e->getMessage();} as suggested in the other answer. As it will display only the php_network_getaddresses: getaddrinfo failed message but won't provide a clue with incorrect hostname or other important details. Always leave the PDOException alone.

A minimalistic correct example for connecting MySQL would be like this.

First, create a file database_config.php that only contains the database credentials, as they are going to be different on each host

<?php
$db_host = '127.0.0.1';
$db_name = 'your database name'
$db_user = 'your username';
$db_pass = 'your password';
$db_port = '3306'; // or the actual port if it's different

then create the database_connection.php file like this

<?php
require __DIR__."/database_config.php";
$dsn = "mysql:host=$db_host;dbname=$db_name;port=$db_port;charset=utf8mb4";
$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];
$pdo = new PDO($dsn, $db_user, $db_pass, $options);

and then include this file in any script that needs a database connection.

Note that on a live server you must configure the PHP's display_errors option to off, so database errors won't be displayed to the end users. Instead, configure the log_errors option to on so the errors will be logged instead.

PDOException: PDO::__construct(): php_network_getaddresses: getaddrinfo failed: no such host known

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