orm - 请解释 Laravel ORM 中的foreign_key 和 local_key 关系

Question

我正在有效地尝试定义用户(发送者和接收者)与消息之间的关系。

“我的消息”迁移是:

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateMessagesTable extends Migration {

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        //
        Schema::create('messages', function($t){
            $t->increments('id');
            $t->integer('sender_user_id')->unsigned();
            $t->integer('recipient_user_id')->unsigned();
            $t->string('subject');
            $t->text('content');
            $t->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        //
        Schema::dropIfExists('messages');
    }

}

我的消息模型很简单:

<?php

class Message extends Eloquent{
    // link to sender user id
    public function from(){
        return $this->hasOne('User', 'sender_user_id'); 
    }
    // link to recipient user id
    public function to(){
        return $this->hasOne('User', 'recipient_user_id');
    }
}

但我不确定在我的用户模型中定义 hasMany 关系。

文档 ( http://laravel.com/docs/eloquent#relationships ) 显示以下内容:

return $this->hasMany('Comment', 'foreign_key');

return $this->hasMany('Comment', 'foreign_key', 'local_key');

现在，我很困惑后一个 hasMany 关系中哪个键是哪个。哪个对于我的用户模型是正确的？

public function sentMessages(){
    return $this->hasMany('Messages', 'id', 'sender_user_id');
}

public function sentMessages(){
    return $this->hasMany('Messages', 'sender_user_id', 'id');
}

Answer 1

您必须像这样设置关系:

public function sentMessages()
{
    return $this->hasMany('Messages', 'sender_user_id');
}

public function receivedMessages()
{
    return $this->hasMany('Messages', 'recipient_user_id');
}