在中创建两个条目 config/database.php :

'connections' => array(

    # Connection one
    'mysql_1' => array(
        'driver'    => 'mysql_1',
        'host'      => 'host_1',
        'database'  => 'db_1',
        'username'  => 'username_1',
        'password'  => 'password_1'
        'charset'   => 'utf8',
        'collation' => 'utf8_unicode_ci',
        'prefix'    => '',
    ),

    # Connection two
    'mysql_2' => array(
        'driver'    => 'mysql_2',
        'host'      => 'host_2',
        'database'  => 'db_2',
        'username'  => 'username_2',
        'password'  => 'password_2'
        'charset'   => 'utf8',
        'collation' => 'utf8_unicode_ci',
        'prefix'    => '',
    ),
),

为每组模型创建一个基本模型或特征，在模型级别设置连接。将所有模型更改为从各自的基础模型扩展而来。
基本模型

class BaseGroupOneModel extends Model
{
    protected $connection = 'mysql_1';
}

class BaseGroupTwoModel extends Model
{
    protected $connection = 'mysql_2';
}

特点

trait GroupOneTrait
{
    protected $connection = 'mysql_1';
}

trait GroupTwoTrait
{
    protected $connection = 'mysql_2';
}

class GroupOneModel extends Model
{
    use app/Models/Traits/GroupOneTrait;
}

class GroupTwoModel extends Model
{
    use app/Models/Traits/GroupTwoTrait;
}