Eloquent - Eager 加载关系

问题描述

我想弄清楚如何从相关表中预先加载数据.我有 2 个模型 Group 和 GroupTextPost.

I'm trying to figure out how to eager load data from a related table. I have 2 models Group and GroupTextPost.

Group.php

<?php

namespace AppModels;

use IlluminateDatabaseEloquentModel;

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

    public function type()
    {
        return $this->hasOne('AppModelsGroupType');
    }

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

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

GroupTextPost.php

<?php

namespace AppModels;

use IlluminateDatabaseEloquentModel;

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

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

    public function group()
    {
        return $this->belongsTo('AppModelsGroup');
    }
}

我想要做的是在获取群组文本帖子时预先加载 user，以便在我提取消息时包含用户名.

What I'm trying to do is eager load the user when fetching group text posts so that when I pull the messages the user's name is included.

我试过这样做:

public function messages()
{
    return $this->hasMany('AppModelsGroupTextPost')->with('user');
}

...并像这样调用:

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

但我收到一个错误:

Unhandled Exception: Call to undefined method IlluminateDatabaseQueryBuilder::firstname()

这可能与 Eloquent 相关吗?

Is this possible to do with Eloquent?

推荐答案

你不应该直接在关系上预先加载.您可以始终在 GroupTextPost 模型上预先加载用户.

You should not eager load directly on the relationship. You could eager load the user always on the GroupTextPost model.

GroupTextPost.php

GroupTextPost.php

<?php

namespace AppModels;

use IlluminateDatabaseEloquentModel;

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('AppModelsUser');
    }

    public function group()
    {
        return $this->belongsTo('AppModelsGroup');
    }
}

或者你可以使用嵌套急切加载

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

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