possible to assign db_name(Database.php) in a variable or any other option

You can also pass the entire connection group to the connect method:

PHP Code:

$custom = [
            'DSN'      => '',
            'hostname' => 'localhost',
            'username' => '',
            'password' => '',
            'database' => '',
            'DBDriver' => 'MySQLi',
            'DBPrefix' => '',
            'pConnect' => false,
            'DBDebug'  => (ENVIRONMENT !== 'production'),
            'cacheOn'  => false,
            'cacheDir' => '',
            'charset'  => 'utf8',
            'DBCollat' => 'utf8_general_ci',
            'swapPre'  => '',
            'encrypt'  => false,
            'compress' => false,
            'strictOn' => false,
            'failover' => [],
            'port'     => 3306,
    ];
$db = \Config\Database::connect($custom); 


One possible solution to make this a "global" is to create a new method in Config\Services.php that determines which is the correct database to connect to for this page view and return a shared instance of the database connection with the appropriate connection. Then, each time you call that method during that load it will return that same database connection.

Support Development •  CodeIgniter 4 Foundations • Practical CodeIgniter 3  • CodeIgniter Tutorials