Laravel雄辩的模特关系

Question

My app builds on

Laravel: 5.6.35
PHP 7.2.4
Entrust: 1.9

My Role model

class Role extends EntrustRole
{
    public function permissions()
    {
        return $this->belongsToMany(Permission::class);
    }

    public function users()
    {
        return $this->hasMany(User::class);
    }
}

And my User model is

class User extends Authenticatable
{
    public function role()
    {
        return $this->belongsTo(Role::class);
    } 
}

And now you can notice in Tinker

D:\work\www\myapp>php artisan tinker
Psy Shell v0.9.7 (PHP 7.2.4 — cli) by Justin Hileman
>>> App\models\Role::find(1)->users()->get()
Illuminate/Database/QueryException with message 'SQLSTATE[42S22]: Column not found: 1054 Unknown column 'users.role_id' in 'where clause' (SQL: select * from `users` where `users`.`role_id` = 1 and `users`.`role_id` is not null)'
>>> App\User::find(1)->role()->get();
=> Illuminate\Database\Eloquent\Collection {#2937
     all: [],
   }
>>> App\User::find(1)->roles()->get();
=> Illuminate\Database\Eloquent\Collection {#2941
     all: [
       App\models\Role {#2930
         id: 1,
         name: "super-admin",
         display_name: "Super Admin",
         description: "This will be one permission, that can not be assigned or modified.",
         created_at: "2018-09-07 12:11:35",
         updated_at: "2018-09-07 12:11:35",
         pivot: Illuminate\Database\Eloquent\Relations\Pivot {#2927
           user_id: 1,
           role_id: 1,
         },
       },
     ],
   }

I am getting result for App\User::find(1)->roles(), but my User model has function role(), and empty collection for App\User::find(1)->role() and error for App\models\Role::find(1)->users()

so please give some idea, how to solve this issue?

Answer 1

I think I found the answer to my question here.if you have properly defined relations through hasMany and belongsTo in your models, but haven't provided foreign key in the table of the model who belongsTo other table, your relations won't work. In documentation too, it suggests to use foreign_key to use One-to-Many relationship.

Entrust database design is based on many-to-many relationship. So that user can have multiple roles.Purly as described in Laravel documentation.