Laravel 4:如何在一对多关系中检索数据


Laravel 4 : How to retrieve data in a one-to-many relationship?

(参见下面的代码(

我有两个模型User和Messages。我想根据每个输入的会话id,获取10条消息(及其关联的发件人名称(,并反转数据。我已经成功地收到了这些消息,但无法将其缩小到每次对话10条消息/以及相关的发件人姓名。

  1. 我已经尝试过将消息数据与用户数据一起返回,但要么我不知道如何访问发件人的姓名,要么它不返回关联的用户:

    $allMessages = Messages::with('User')->whereIn('conv_id',$conv_id);
    
  2. 我也尝试过返回10条消息,但它会根据收到的所有消息而不是每次对话返回10条信息。

    $allMessages = Messages::whereIn('conv_id',$conv_id)->take(10);
    

如何根据每个会话的id以及消息的相关发件人名称获得10条消息?代码改进的奖励积分。提前谢谢!


用户模型

public function messages(){
    return $this->hasMany('Messages');
}

消息模型

public function user(){
    return $this->belongsTo('User');
}

控制器

public function index()
    {
        $timestamps = Input::get('from'); //timestamp of latest message
        $conv_id = Input::get('conv_id'); //array of conversation ids
        $allMessages = Messages::whereIn('conv_id',$conv_id);
        if(is_null($timestamps)){
           $messages = $allMessages->orderBy('created_at','desc');
        }else{
           asort($timestamps);
           $messages = $allMessages->where('created_at','>',end($timestamps));
        }
        return $messages->get()->reverse();
    }

迁移

消息表

Schema::create('messages', function(Blueprint $table)
        {
            $table->increments('id');
            $table->integer('user_id');
            $table->integer('conv_id');
            $table->text('body');
            $table->timestamps();
        });

用户表

Schema::create('users',function($table)
        {
            $table->increments('id');
            $table->string('email')->unique();
            $table->string('password',100);
            $table->string('name',150);
            $table->string('usertype',50);
            $table->boolean('block');
            $table->string('remember_token',100);
            $table->timestamp('lastlogin_at');
            $table->timestamps();
            $table->softDeletes();
        });

编辑:铬中WereWolf答案的var_dump预览结果

0: {id:37, user_id:1, conv_id:2, body:damn mate, created_at:2014-06-20 00:55:32,…}
1: {id:38, user_id:1, conv_id:2, body:hello, created_at:2014-06-20 02:18:21,…}
2: {id:39, user_id:1, conv_id:2, body:dude, created_at:2014-06-20 02:20:10,…}
3: {id:40, user_id:1, conv_id:2, body:test, created_at:2014-06-20 06:52:37,…}
4: {id:67, user_id:1, conv_id:2, body:haha, created_at:2014-06-21 01:25:56,…}
5: {id:68, user_id:1, conv_id:2, body:hey, created_at:2014-06-21 01:26:14, updated_at:2014-06-21 01:26:14,…}
6: {id:69, user_id:1, conv_id:1, body:testa, created_at:2014-06-21 01:27:02,…}
7: {id:70, user_id:1, conv_id:1, body:testser, created_at:2014-06-21 01:27:32,…}
8: {id:115, user_id:1, conv_id:2, body:haha, created_at:2014-06-21 02:45:06,…}
9: {id:116, user_id:1, conv_id:2, body:test, created_at:2014-06-21 02:57:03,…}

你可以试试这个:

$allMessages = Messages::with('user')
                       ->where('conv_id', $conv_id)
                       ->take(10)
                       ->get();

这将返回Messages模型的集合,因此您需要像一样循环

@foreach($allMessages as $message)
    {{ $message->user->name }}
    {{ $message->body }}
@endforeach

此外,您可以使用:

// Get the first message and then user->name
$allMessages->first()->user->name;
// Get the second message and then user->name
$allMessages->get(1)->user->name;
public function PurchaseReport () {
            $heartsPurReport = DB::table('users')
                        ->join('heartz_payment', 'users.id', '=', 'heartz_payment.user_id')
                        ->join('heartz_transaction', 'users.id', '=', 'heartz_transaction.user_id')
                        ->select('users.username', 'users.email', 'heartz_payment.heartz', 'heartz_payment.transaction_id', 'heartz_payment.order_id', 'heartz_payment.created_at', 'heartz_payment.status',  'heartz_payment.amount', 'heartz_transaction.event')->paginate(20);

//dd(json_encode($heartsPurReport((;

                        return view('Reports.Heartz.Purchase')->with('heartz',  $heartsPurReport);                          
    }

//在视图中,使用foreach循环,并在foreach循环之外使用以下内容进行分页

                       {!! $consumption->render() !!}