Laravel一个域，由Session检测到多个数据库

I have read several posts/topics (like this, this and this) about the subject SaaS, Multi-Tenant, etc. and I reached the conclusion that most of them does not fit my requirements:

1. I don't need a multi-tenant as i'm only going to use the main-domain
2. I can't write in .env nor in database.config all my MySQL connections as they will all be dynamic (at least the name of the database)

Workflow i need:

1. The subscriptions (SaaS) contains the database name
2. Whenever the user login it is assigned to his session the database name
3. Run all the queries to the user database

Example:

- project_admin <- Main database 
--- subscriptions <- Table
------ id | db_name
------ 1  | project_child_one
------ 2  | project_child_two
--- users <- Table
------ id | subscription_id 
------ 1  | 1 
------ 2  | 2

- project_child_one <- Child database
--- customers <- table

- project_child_two <- Child database
--- customers <- table

• When the user 1 login, the data retrieved from customers should be from database project_child_one.
• When the user 2 login, the data retrieved from customers should be from database project_child_two.

I want the database name to be saved in the session so I don't need to always query the project_admin in order to know in which database the user should connect to. This is the easy part.

If you really need to have a “tenant” database connection, then you can configure it on the fly in a middleware class:

class ConfigureTenantConnection
{
    public function handle($request, Closure $next)
    {
        if ($user = $request->user()) {
            // Create a tenant database connection if there is an authenticated user
            config([
                'database.connections.tenant' => [
                    'driver' => 'mysql',
                    // I don’t know what column names you use, but…
                    'host' => $user->database_host,
                    'port' => $user->database_port,
                    'database' => $user->database_name,
                    'username' => $user->database_username,
                    'password' => $user->database_password,
                ],
            ]);
        }

        return $next($request);
    }
}

You can then use this tenant connection in database queries and models:

abstract class TenantModel extends Model
{
    protected $connection = 'tenant';
}

class Widget extends TenantModel
{
    protected $table = 'widgets';
}

Well I am not sure whether this is what you meant . But if you want db name to be dynamic you can easily do it in the laravel as follows . The connections part of config should be like above . However you can change the database credential at the controller in the runtime . If we take the above example for the configuration then . You can do like this on the controller .

    $config= [
            'database'=>'Dynamic db name',
    ];
    Config::set("database.connections.mysql2",$config);
    DB::purge('mysql');
    DB::setDefaultConnection('mysql2');

And suppose you want to switch another db after transaction you can do like this

     $config= [
            'database'=>'Dynamic db name',
    ];
    Config::set("database.connections.mysql",$config);
    DB::purge('mysql2');
    DB::setDefaultConnection('mysql2');

I hope it helps