从与“懒惰的渴望加载"的关系中返回第一个元素[Laravel 5.2] [英] Return first element from relation with `Lazy Eager Loading` [Laravel 5.2]

问题描述

我有这样的关系:

public function message()
{
   return $this->hasMany('Engine\Message');
}

在我的Conversation模型中.

对于每次对话，我都需要获取最新消息.

and for each conversation I need to get last message.

这是我尝试过的方法，但这只会在第一次对话中收到一条消息，而不会从其他对话中收到消息...

Here is what I tried, but this will get only one message for first conversation but will not get message from other conversations...

$con = Conversation::all();

$con->load(['message' => function ($q) use ( &$mess ) {
                $mess = $q->first();
            }]);

return $con;

我不希望查询每条记录...有人知道如何解决此问题吗?

I don't wana query for each record... Anyone know how to solve this problem?

推荐答案

如建议在急切加载中不要使用first()或get()，您应该在模型中创建新的关系.

Don't use first() or get() in eager loadings you should create a new relationship in the model.

模型看起来像这样...

The model would look something like this...

public function message()

{

    return $this->hasOne('Engine\Message');

}

对"pmall"表示敬意

kudos to 'pmall'

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