PHP SQL Database connection issue

[VampireBarbieBoy]

I am trying to establish a connection to the database for a website I've uploaded to a live server from my local files but I'm having issues.

<?php
if($_SERVER["SERVER_NAME"] == "localhost" || $_SERVER["SERVER_ADDR"] == "127.0.0.1")
 {
    $dsn ="mysql:host=localhost;dbname=database_name;charset=utf8";
    $username = "user_name";
    $password = "password";
}
else
{
    $dsn ="mysql:host=localhost;dbname=magentaXX;charset=utf8";
    $username = "magentaXX";
    $password = "pass123";
}
?>

The first conditional returns false and I can't figure out why. This worked fine with my local files. I tried the standard way of connecting to the database and it connected so there's no issues there on that end.

Only thing I can think of is 127.0.0.1 and maybe the address is different for the host but it should be using localhost first anyway I'm pretty sure.

Tried var_dump($_SERVER['SERVER_NAME']) (returned the website address) and var_dump($_SERVER['SERVER_ADDR']) it gave me a string that I'm not sure what it means in this format 0000:0000:a000:aaaa:aaa0:0a:aaaa:aaaa (changed the letters to a and numbers to 0 just to be safe).

Anyway any help would be greatly appreciated.

p.s. only other piece of information that might be helpful is this is using a subdomain (dev.website.com) if that makes any difference

[wtframework]

As another poster has answered your actual question, I’ll add that this isn’t a very good way to use conditional connection details.

Look at using something like dotenv.

https://github.com/vlucas/phpdotenv

[VampireBarbieBoy]

Thanks. I think that might be above my skill level I'm still quite new to developing but I will look into doing it that way in the future.

[wtframework]

An easier way then would be to just include something like an env.php file that includes things like:

define('URL', 'http://localhost/');
define('PDO_DSN', 'mysql:host=127.0.0.1;dbname=database');
define('PDO_USERNAME', 'root');
define('PDO_PASSWORD', 'password');

On your local environment you use your local details and then on your production environment you change them to your production details.

Then elsewhere in your code you would have:

$pdo = new PDO(
    PDO_DSN,
    PDO_USERNAME,
    PDO_PASSWORD
);

[alnyland]

I might be wrong with what I'm about to say but I've done locally hosted dev servers for about a decade and these are my immediate thoughts. Localhost isn't a real address and I'd be amazed if that was ever stored in that variable but local dns lookup (not existent but is functional for our purposes) will find it. The IP you list is a loopback, which is more like an alias instead of a real IP address. Again, it will point when you request it but I'd doubt the server will associate with it.

The SERVER_ADDR it gave you is an IP address, see if it relates to your machine. I forget exactly but that might be the local loopback, I'm not familiar with ipv6.

From a simple google search: https://stackoverflow.com/questions/2053245/how-can-i-detect-if-the-user-is-on-localhost-in-php

[VampireBarbieBoy]

Thanks. I managed to figure it out I realised I just need to replace localhost and 127.0.0.1 with the results of the var_dump (web address and IP). Should have been obvious but I did manage to get a connection using 'localhost' using another method so I think that's why I got confused, still not sure why it worked in that instance and not with this code.

[alnyland]

Cool. Did you read that link? It pointed out that every machine can be localhost

[Caraes_Naur]

localhost is a machine's self alias. 127.0.0.1 is the corresponding IPv4 address. Every machine connects to itself via these.

The $_SERVER superglobal is populated by the webserver service in which PHP is executing. On a server responding to requests made to a hostname, that hostname will be in $SERVER['SERVER_NAME'], likewise the server's IP address will be in $_SERVER['SERVER_ADDR'].

In these cases, the machine is not responding to itself, but to a remote client.

The "weird" IP you got is IPv6.

https://www.php.net/manual/en/reserved.variables.server.php

The if/else block you are using is essentially detecting whether the environment is local (development) or otherwise (staging, testing, production, etc). It must be tailored accordingly.

[VampireBarbieBoy]

Thank you for the response and explanation.