问题

I can help you translate the code-related content:

嘿，各位，我在我的代码中遇到了这个问题，我不知道为什么会显示这个错误：

> Illuminate\\Database\\Eloquent\\Collection::students 方法不存在。

我尝试创建多对多关系，这是我的控制器函数：
```php
public function attach_skill(Request $request) {


            foreach($request->skills as $id){
                dd(Skill::find($request->skills)->students()->attach($request->students));
                return "done";
              }

    }

这是我的学生模型代码：

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Laravel\Sanctum\HasApiTokens;
use Illuminate\Foundation\Auth\User as Authenticatable;
use App\Models\Task;
use App\Models\Skill;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;

class Students extends Authenticatable
{
    use HasFactory, HasApiTokens;
    protected $fillable = [
        'name',
        'student_id',
        'phone',
        'password',
        'email',
        'major',
        'GPA',
        'Department',
        'address',
    ];

    protected $hidden = [
        'password',
        'remember_token',
        'email',
        'natioal_id'
    ];

    public $table = "students";
    protected $primaryKey = 'student_id';

    public function tasks() {
        return $this->belongsToMany(Task::class,'student_task','task_id','student_id');
    }

    public function taskk() {
        return $this->belongsToMany(Task::class,'student_task','student_id','task_id');
    }

    public function skill() {
        return $this->belongsToMany(Skill::class, 'student_skill', 'skill_id', 'student_id');
    }

    public function skilll() {
        return $this->belongsToMany(Skill::class, 'student_skill', 'student_id','skill_id');
    }

}

这是我的技能模型代码：

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use App\Models\Students;

class Skill extends Model
{
    use HasFactory;

    protected $fillable = [
        'skill_type',
    ];

    protected $primaryKey = 'skill_id';
    public function students() {
        return $this->belongsToMany(Students::class,'student_skill','skill_id','student_id');
    }

    public function skilll() {
        return $this->belongsToMany(Skill::class, 'student_skill', 'student_id','skill_id');
    }
    public $timestamps = false;

}

我希望学生和技能的请求以数组形式返回，因为我有多个技能和学生。

<details>
<summary>英文:</summary>
hey guys i have this problem in my code , i dont know why is showing this error:
&gt; Method Illuminate\\Database\\Eloquent\\Collection::students does not exist.
i tried to make many to many relation and this is my controller function:

public function attach_skill(Request $request) {

        foreach($request->skills as $id){
dd(Skill::find($request->skills)->students()->attach($request->students));
return "done";
}
}

and this is my student model code:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Laravel\Sanctum\HasApiTokens;
use Illuminate\Foundation\Auth\User as Authenticatable;
use App\Models\Task;
use App\Models\Skill;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;

class Students extends Authenticatable
{
use HasFactory, HasApiTokens;
protected $fillable = [
'name',
'student_id',
'phone',
'password',
'email',
'major',
'GPA',
'Department',
'address',
];

protected $hidden = [
'password',
'remember_token',
'email',
'natioal_id'
];
public $table = "students";
protected $primaryKey = 'student_id';
public function tasks() {
return $this->belongsToMany(Task::class,'student_task','task_id','student_id');
}
public function taskk() {
return $this->belongsToMany(Task::class,'student_task','student_id','task_id');
}
public function skill() {
return $this->belongsToMany(Skill::class, 'student_skill', 'skill_id', 'student_id');
}
public function skilll() {
return $this->belongsToMany(Skill::class, 'student_skill', 'student_id','skill_id');
}

}

and this is my skill model code:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use App\Models\Students;

class Skill extends Model
{
use HasFactory;

protected $fillable = [
'skill_type',
];
protected $primaryKey = 'skill_id';
public function students() {
return $this->belongsToMany(Students::class,'student_skill','skill_id','student_id');
}
public function skilll() {
return $this->belongsToMany(Skill::class, 'student_skill', 'student_id','skill_id');
}
public $timestamps = false;

}

i want students and skills request in array becuse i have my skills and many students.
</details>
# 答案1
**得分**: 1
因为您正在将一个数组传递给 `find()` 方法，这是错误的，请传递 `$id` 而不是 `$request->skills`，如果您正在循环中进行迭代，请执行以下操作：
```php
public function attach_skill(Request $request) {
foreach($request->skills as $id){
dd(Skill::find($id)->students()->attach($request->students));
return "done";
}
}

public function attach_skill(Request $request) {
foreach($request->skills as $id){
dd(Skill::find($id)->students()->attach($request->students));
return "done";
}
}