Using a numeric value as a key for a database connection in config file will result in it not being loaded with that name.

[ItsClassified]

Laravel Version

11.23.5

PHP Version

8.3.11

Database Driver & Version

MySQL

Description

When using numeric values in the database.php config file Laravel will disregard the names and load them starting from 0, and increasing for each connection after that with a numeric value as name.

@ollieread found that commenting out row 127 in the following file makes it load in again: https://github.com/laravel/framework/blob/11.x/src/Illuminate/Foundation/Bootstrap/LoadConfiguration.php#L103

The issue appears to be on L103 using array_merge

Steps To Reproduce

Change a connection name to a numeric string, for example: '12345' and try to access it using DB::connection.

[ollieread]

Just to add a bit more, the issue is when it tries to merge database.connections, as PHPs array_merge() is doing some annoying type juggling and assuming keys that are numeric strings, are, in fact, just numeric, and it's resetting those keys.

[crynobone]

I don't think we have considered using an integer key as a valid configuration key. Moving this into Ideas for now and feel free to discuss this further.

[crynobone]

https://www.php.net/manual/en/language.types.array.php#language.types.array.syntax

[crynobone]

https://www.php.net/manual/en/language.types.array.php#language.types.array.syntax

[rodrigopedra]

PHP lets you use numeric strings as array keys, and you can access them as both numbers and strings.

Numeric strings, that represent valid integers, are cast to integers on both offset set and offset get operations.

That is different from using "numeric strings" as keys.

This issue is not that you can't use integer keys, it's that you can't use string keys that PHP may interpret as a number.

That is the expected behavior, from PHP's perspective.

<?php

$arr = ['0' => 'foo', '1' => 'bar'];

// - keys will be dumped as integers
// - \array_list($arr) will return true
\var_dump($arr, \array_is_list($arr));

$arr['03'] = 'baz';

// - only the new key will be quoted as a string
// - \array_list($arr) will return false
\var_dump($arr, \array_is_list($arr));

array(2) {
  [0]=>
  string(3) "foo"
  [1]=>
  string(3) "bar"
}
bool(true)
array(3) {
  [0]=>
  string(3) "foo"
  [1]=>
  string(3) "bar"
  ["03"]=>
  string(3) "baz"
}
bool(false)

Reference: https://3v4l.org/8cei8

So we aren't facing a bug where you can't use ints, but rather you can't use some strings.

If you believe this is a bug, I'd consider it'd be better to open a bug report to PHP.

[ollieread]

If you believe this is a bug, I'd consider it'd be better to open a bug report to PHP.

@rodrigopedra When adding an entry to an array with a string key that is a valid integer, it is cast. When accessing that entry in the array, the key you provide is also cast, so you can access as either an int or a string.

There is nothing wrong with this, at all. After all, this is how the language works.

The problem, is that Laravel merges several configuration values with their defaults, which overwrites these keys, ostensibly changing the name of the connection. I'm still yet to find the reasoning behind this merge, or its purpose, but either way, it changes the way you can define connections.

[rodrigopedra]

@ollieread I see now what the issue is.

Well, as @donnysim said, you can disable configuration merge, and use the config:publish command to publish any missing config file.

I wasn't a big fan of this change - regarding auto-merging configuration - on Laravel 11. But I guess this ship has sailed.

Another option, is to propose a PR to change how Illuminate\Foundation\Bootstrap\LoadConfiguration@loadConfigurationFile works, to use some sort of deep-merge algorithm instead of using array_merge().