Question

我想在Laravel 5.1中执行以下查询

SELECT *, max(m2.created_at) createdat FROM `messages` m1 left join messages m2 
on (m1.id=m2.parent_id) where m1.parent_id=0 group by m1.id order by createdat desc

以下是我的'消息'表

id |parent_id |message_content |created_at
2  |0         |hello           |2015-08-10 10:32:16
3  |0         |Hello Again     |2015-08-10 10:33:25
4  |0         |how are you.This|2015-10-19 16:34:56
24 |2         |hi from a       |2016-01-07 11:37:21
25 |4         |ok              |2016-01-07 11:38:23
26 |3         |now its here2   |2016-01-07 11:38:38
27 |4         |4th on top1     |2016-01-07 11:39:32
28 |3         |3rd on top1     |2016-01-07 11:46:56
29 |2         |2nd on top1     |2016-01-07 11:47:12
30 |3         |3rd on top2     |2016-01-07 11:47:24
31 |4         |4th on top2     |2016-01-07 11:47:36

我使用Laravel代码下面的代码

$messages = Message::select(DB::raw('*,max(m2.created_at) as createdAt'))->leftJoin('messages as m2','m2.parent_id','=','messages.id')
            ->Parent()
            ->groupBy('messages.id')
            ->orderBy('createdAt','desc')
            ->get();

这是我的Parent（）范围

public function scopeParent($query)
    {
        return $query->where('messages.parent_id', '=', '0');
    }

是否有可能在不使用“leftJoin”和纯粹雄辩的方式的情况下完成它？

如何自我加入使用eloquent with order by和group by

0 个答案: