在laravel 5中使用左连接将查询生成器转换为Eloquent ORM

Question

我使用查询构建器进行查询。

我的查询：

$customer = DB::select(DB::raw('select *, CONCAT(lastname,", ",firstname, " ", if (middlename = null, "", middlename)) as fullname from customer
                                LEFT JOIN
                                (
                                     select id,max(id) as maxCustomer from customer
                                ) c on c.id = customer.id
                                where subscriber_id like "%'.$input.'%"
                                or lastname like "%'.$input.'%"
                                or firstname like "%'.$input.'%"
                                or middlename like "%'.$input.'%"
                                or CONCAT(lastname,", ",firstname, " ",middlename) like "%'.$input.'%"'));

我想将其转换为雄辩，因为我想使用laravel eager load。当我使用$ customer-＆gt; load时，它有一个错误，在非对象上调用成员函数load（）。我很难将左连接部分转换为雄辩。