Laravel 5: Change Default Database connection Dynamically | Change database name of connection on the fly | How to change default database connection in controller | Multiple DB Connections | Specifying DB connection information dynamically instead of config key | How to Use Multiple Database Connections in Laravel Application

use Illuminate\Config\Repository;

public function __construct(Repository $config) {}

So now you can $config from the above reference.

Below is a sample usage of change database name:

$config->set("database.connections.mysql.database", "test");

or

app()->config->set("database.connections.mysql.database", "test");

You can use this functionality in middle-ware.

If your app already connected then you have to disconnect it before make new connection available.

Below follow steps to disconnect connection:

$dm = app("Illuminate\\Database\\DatabaseManager");

$dm->disconnect();