雄辩 - 渴望加载关系

Question

我正在试图弄清楚如何从相关表中加载数据.我有2个型号Group和GroupTextPost.

Group.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Group extends Model
{
    protected $table = 'group';

    public function type()
    {
        return $this->hasOne('\App\Models\GroupType');
    }

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

    public function messages()
    {
        return $this->hasMany('\App\Models\GroupTextPost');
    }
}

GroupTextPost.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class GroupTextPost extends Model
{
    protected $table = 'group_text_post';

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

    public function group()
    {
        return $this->belongsTo('\App\Models\Group');
    }
}

我正在尝试做的是user在获取组文本帖子时急切加载,以便在我拉消息时包含用户名.

我试过这样做:

public function messages()
{
    return $this->hasMany('\App\Models\GroupTextPost')->with('user');
}

......并且这样打电话:

$group = Group::find($groupID);
$group->messages[0]->firstname

但是我收到一个错误:

Unhandled Exception: Call to undefined method Illuminate\Database\Query\Builder::firstname()

这可能与Eloquent有关吗？

Answer 1

你不应该直接加载关系.您可以始终在GroupTextPost模型上急切加载用户.

GroupTextPost.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class GroupTextPost extends Model
{
    protected $table = 'group_text_post';

    /**
     * The relations to eager load on every query.
     *
     * @var array
     */
    protected $with = ['user'];

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

    public function group()
    {
        return $this->belongsTo('\App\Models\Group');
    }
}

或者您可以使用嵌套预先加载

$group = Group::with(['messages.user'])->find($groupID);
$group->messages[0]->user->firstname