php - SQLSTATE[42S22] : Column not found: 1054 Unknown column one to many(inverse) relation laravel

Question

我有两个模型 Tour.php 和 TourCategory.php:

Tour.php

protected $table = `tours`;

public function category() 
{
    return $this->belongsTo('App\TourCategory');
}

TourCategory.php

protected $table = 'tcategories';

public function tours()
{
    return $this->hasMany('App\Tour');
}

我的数据库表如下:

游览表

id|title|category_id|content|

tcatgegories 表

id|name

我想用以下代码显示属于某个类别的所有游览:

    @foreach ($category->tours as $tour)
     <tr>
        <th>{{ $tour->id}}</th>
        <td>{{ $tour->title}}</td>
        <td>
            <span class="label label-default">{{$category->name}}</span>
        </td>
     </tr>
    @endforeach

使用上面的代码，我得到以下错误:

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'tours.tour_category_id' in
'where clause' (SQL: select * from `tours` where `tours`.`tour_category_id` = 1 and 
`tours`.`tour_category_id` is not null) (View: F:\multiauth_tutorial-master\resources\
views\admin\categories\show.blade.php

我之前的项目也使用了相同的代码，但没有出现任何错误。还是我遗漏了什么？

Answer 1

Eloquent determines the default foreign key name by examining the name of the relationship method and suffixing the method name with _id. However, if the foreign key on the model is not *_id, you may pass a custom key name as the second argument to the belongsTo method

所以，你需要specify a foreign key :

public function category() 
{
    return $this->belongsTo('App\TourCategory', 'category_id');
}

You may also override the foreign and local keys by passing additional arguments to the hasMany method.

public function tours()
{
    return $this->hasMany('App\Tour', 'category_id');
}

https://laravel.com/docs/5.4/eloquent-relationships#one-to-many

或者在旅游表中使用tour_category_id而不是category_id。