Laravel属于关系 [英] Laravel belongsTo Relationship

问题描述

我有一个扩展Eloguent的Feeds模式。

我创建了一个名为User的关系函数。

  public function user（）{
 return $这 - >属于关联（ '用户'）; （我也尝试返回$ this-> belongsTo（'User'，'user_id'）; 
} 
  

在我想要做的事情上：

  @foreach（$ feeds as $ feed）
 {{$ feed-> user（） - > first_name}} {{$ feed-> user（） - > last_name}} 
 @endforeach 
  

但我收到此错误Undefined属性：Illuminate\Database\Eloquent\Relations\BelongsTo :: $ last_name

当我做$ feed-> user-> first_name它工作正常，但我认为user（） - > first_name更有效率，我做错了什么？

这是数据库的字段和数据类型：

feed

  feed_id INT 
 user_id INT 
 feed文本
 created_at TIMESTAMP 
 updated_at TIMSTAMP 
 school_id INT 
  

用户

  user_id INT 
 username VARCHAR 
密码VARCHAR 
 first_name VARCHAR 
 last_name VARCH AR 
 created_at TIMESTAMP 
 updated_at TIMESTAMP 
  

解决方案

p>使用动态属性

  $ feed-> user-> first_name; 
  

当您使用动态属性时，与执行以下操作相同，除了Laravel为您使用魔术 __ call（）方法。

  $ feed-> user（） - > first（） - > first_name; 
  

只需使用$ feed-> user（）函数即可获得允许您在另一端提取实体之前，添加额外的约束和与关系。

Ok, I am a little confused with the belongsTo relationship for Models.

I have a Feeds model that extends Eloguent.

I have created a relationship function called User.

public function user(){
return $this->belongsTo('User'); (and I also tried return $this->belongsTo('User', 'user_id');
}

On the view I am trying to do :

@foreach($feeds as $feed)
{{$feed->user()->first_name}} {{$feed->user()->last_name}}
@endforeach

but I am getting this error Undefined property: Illuminate\Database\Eloquent\Relations\BelongsTo::$last_name

When I do $feed->user->first_name it works fine, but I thought user()->first_name was more efficient. What am I doing wrong?

This are the fields and data types of the database:

feeds

feed_id INT
user_id INT
feed Text
created_at TIMESTAMP
updated_at TIMSTAMP
school_id INT

users

user_id INT
username VARCHAR
password VARCHAR
first_name VARCHAR
last_name VARCHAR
created_at TIMESTAMP
updated_at TIMESTAMP

解决方案

Use the dynamic property

$feed->user->first_name;

When you use the dynamic property it is the same as doing the below except Laravel does it for you using the magic __call() method.

$feed->user()->first()->first_name;

using just the function $feed->user() allows you to get the relationship which allows you to add extra constraints and with relations before fetching the entity on the other end.

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