在运行时更改laravel中的默认数据库

// 配置文件中定义的数据库连接
'connections' => [
    'mysql' => [
        'driver' => 'mysql',
        'host' => env('DB_HOST', '127.0.0.1'),
        'port' => env('DB_PORT', '3306'),
        'database' => env('DB_DATABASE', 'forge'),
        'username' => env('DB_USERNAME', 'forge'),
        'password' => env('DB_PASSWORD', ''),
        // ...
    ],
    'pgsql' => [
        'driver' => 'pgsql',
        'host' => env('DB_HOST_PGSQL', '127.0.0.1'),
        'port' => env('DB_PORT_PGSQL', '5432'),
        'database' => env('DB_DATABASE_PGSQL', 'forge'),
        'username' => env('DB_USERNAME_PGSQL', 'forge'),
        'password' => env('DB_PASSWORD_PGSQL', ''),
        // ...
    ],
],

// 数据库连接管理器类
class DatabaseManager {
    public function switchConnection($connectionName) {
        config(['database.default' => $connectionName]);
    }
}

// 在某个适当的位置调用数据库连接管理器
$databaseManager = new DatabaseManager();
$databaseManager->switchConnection('pgsql');