"Access denied for user ''@'localhost' to database 'forge" appears randomly

Question

I have a search function for my database but sometimes I get this message:

[2016-02-04 07:03:18] local.ERROR: PDOException: SQLSTATE[HY000] [1044] Access denied for user ''@'localhost' to database 'forge' in C:\xampp\htdocs\reko\api\vendor\laravel\framework\src\Illuminate\Database\Connectors\Connector.php:55
Stack trace:
#0 C:\xampp\htdocs\reko\api\vendor\laravel\framework\src\Illuminate\Database\Connectors\Connector.php(55): PDO->__construct('mysql:host=loca...', 'forge', '', Array)
...

In one of ten calls I get this 500 error message, but I don't know why. The other calls give the right result.

.env

APP_ENV=local
APP_DEBUG=true
APP_KEY=bJM6O0MnrIPaTNwKKOqNJkGinRDv1fnc

DB_HOST=localhost
DB_DATABASE=reko
DB_USERNAME=root
DB_PASSWORD=

CACHE_DRIVER=file
SESSION_DRIVER=file
QUEUE_DRIVER=sync

Search function:

public function search(Modul $modul, Request $request)
{
    $question = Question::whereModulId($modul->id)
        ->where('value', 'LIKE', '%' . $request->get('keywords') . '%')
        ->with('tags')
        ->whereHas('exams', function ($query) use ($request) {
            $query->where('date', '>=', $request->get('year').'-01-01');
        });
    if (!$request->get('parent'))
        $question->where('type', '<>', 'parent');
    if (!$request->get('own'))
        $question->where('type', '<>', 'own');
    if (!$request->get('normal'))
        $question->where('type', '<>', 'normal');
    if ($request->get('answered'))
        $question->has('answers');
    return $question->paginate(10);
}

database.php

'mysql' => [
        'driver'    => 'mysql',
        'host'      => env('DB_HOST', 'localhost'),
        'database'  => env('DB_DATABASE', 'forge'),
        'username'  => env('DB_USERNAME', 'forge'),
        'password'  => env('DB_PASSWORD', ''),
        'charset'   => 'utf8',
        'collation' => 'utf8_unicode_ci',
        'prefix'    => '',
        'strict'    => false,
    ],

I haven't modified the database.php file and all other calls work great.

Answer 1

PLEASE RUN THIS COMMAND

php artisan cache:clear 

THEN

php artisan config:cache

Answer 2

This seems to hold most of the answers : Laravel 5.2 not reading env file

Remember to not to edit your core files as one of the users said. Just do the safe checks, clear cache, should work.

Hope it helps.

As a workaround you can add to your DB forge account with all privileges.