error occured when save data using hasmany relationnship in laravel - php

Question

Create hasmany relatioship in vehicle model and insert data in vehicle and vehicle_staff table. data successfully insert in vehicle table but when store in vehicle_staff following error appear.
Error Comes:
Type error: Argument 1 passed to
Illuminate\Database\Eloquent\Relations\HasOneOrMany::save() must be an
instance of Illuminate\Database\Eloquent\Model, array given, called in
E:\xampp\htdocs\laravel-projects\collegeaccounting\app\Http\Controllers\Transport\VehicleController.php
on line 53
Vehicle Staff Table Schema:
Schema::create('vehicle_staffs', function (Blueprint $table) {
$table->increments('id');
$table->timestamps();
$table->unsignedInteger('vehicles_id');
$table->unsignedInteger('staffs_id');
$table->boolean('status')->default(1);
});
Has Many Relationship on Vehicle Model:
class Vehicle extends BaseModel
{
protected $fillable = ['created_by', 'last_updated_by', 'number', 'type', 'model', 'description', 'status'];
public function staff(){
return $this->hasMany(Staff::class);
}
}
Store Function:
public function store(AddValidation $request)
{
$request->request->add(['created_by' => auth()->user()->id]);
$vehicle = Vehicle::create($request->all());
if ($request->has('staffs_id')) {
$staffs = [];
foreach ($request->get('staffs_id') as $staff) {
$staffs[$staff] = ([
'vehicles_id' => $vehicle->id,
'staffs_id' => $staff
]);
}
$vehicle->staff()->save($staffs);
}
$request->session()->flash($this->message_success, ' Created Successfully.');
return redirect()->route($this->base_route);
}

Answer 1

It seems you are creating many to many relationships, that is to say, a vehicle can belongs to many staffs, and a staff can have many vehicles. So, vehicle_staffs is a intermediate table (or pivot table) between vehicle model and staff model.
For Vehicle model, you should change the staff method to:
public function staff(){
return $this->belongsToMany(Staff::class, 'vehicle_staffs', 'vehicles_id', 'staffs_id');
}
To update many to many relationships, you can attach the staff ids to vehicle:
$vehicle->staff()->attach($staffIds);
and the code change of your store function:
if ($request->has('staffs_id')) {
$staffIds = $request->get('staffs_id');
$vehicle->staff()->attach($staffIds);
}

Answer 2

I don't know what version of Laravel you are using, so I assume you are on Laravel 5.x.
You should probably use saveMany() if you want to save more than one object. It takes a Collection or an array of Models as a parameter.
From the documentation:
If you need to save multiple related models, you may use the saveMany method:
$post = App\Post::find(1);
$post->comments()->saveMany([
new App\Comment(['message' => 'A new comment.']),
new App\Comment(['message' => 'Another comment.']),
]);