Three way Eloquent relationship definition and saving in Laravel

Question

I'm building a Laravel app (with Vue3 and InertiaJS), and I'm attempting to create relationships between three models:

• User
• Area
• WorkHours

where WorkHours is the primary model. In addition to the main data (date, hours, comments, reason), I need to create the following relationships:

1. User - the WorkHours entry is for work performed by the member (aka User), so I need to be able to see total hours for the user for the year. One user can have many WorkHours records.
2. Area - The part of the club that the work hours has been performed in/for. Each WorkHours entry has one approver, and one approver can be associated with many WorkHours entries.
3. Approver - Every Area has specific people that can approve WorkHours entries, and these are defined as approvers in the Area model related to the User model as approver_id (a belongstoMany() relationship both ways). Each WorkHours entry has one approver, but one approver can be associated with many WorkHours entries.

It seems then that the work_hours table should have _id values for each of the three relations (user_id, area_id, and approver_id). However, as I read the Eloquent docs, that means that WorkHours would be a child of both Area and Approver via belongsTo(), since the child gets the _id value of the parent.

So with all that here's the code:

work_hours migrations

    public function up()
    {
        Schema::create('work_hours', function (Blueprint $table) {
            $table->id();
            $table->unsignedBigInteger('user_id');
            $table->unsignedBigInteger('area_id');
            $table->unsignedBigInteger('approver_id');
            $table->date('date');
            $table->decimal('hours', 5, 2);
            $table->string('reason')->nullable();
            $table->string('comments')->nullable();
            $table->timestamps();
            $table->softDeletes();

            $table->foreign('user_id')
                ->references('id')
                ->on('users');

            $table->foreign('approver_id')
                ->references('id')
                ->on('users');

            $table->foreign('area_id')
                ->references('id')
                ->on('areas');
        });
    }

WorkHours

class WorkHours extends Model
{
    use HasFactory, SoftDeletes;

    /**
     * The attributes that are mass assignable.
     *
     * @var array<int, string>
     */
    protected $fillable = [
        'date',
        'hours',
        'reason',
        'comments'
    ];

    public function user()
    {
        return  $this->belongsTo(User::class);
    }

    public function approver()
    {
        return $this->belongsTo(User::class, 'approver_id');
    }

    public function area()
    {
        return $this->belongsTo(Area::class);
    }
}

Area

class Area extends Model
{
    use HasFactory, SoftDeletes;

    protected $fillable = [
        'name'
    ];

    public function approvers()
    {
        return $this->belongsToMany(User::class, 'area_user', 'area_id', 'user_id');
    }

    public function workHours()
    {
        return $this->hasMany(WorkHours::class);
    }
}

User

class User extends Authenticatable
{
    public function workHours()
    {
        return $this->hasMany(WorkHours::class);
    }

    public function areas() {
        return $this->belongsToMany(Area::class);
    }

    public function approval()
    {
        return $this->belongsTo(WorkHours::class, 'approver_id');
    }
}

Now where I'm running into the problem is saving everything when I submit my form to my controller. From my form I have the following pieces of info

• user_id
• area_id
• approver_id
• date
• hours
• reason
• comments

So based on the docs, I would think I would do something like this in WorkHoursController:

    public function store(StoreWorkHoursRequest $request)
    {
        $validated = $request->validated();

        $user = User::find($validated['user']);
        $area = Area::find($validated['area']);
        $approver = User::find($validated['approver']);

        $wh = WorkHours::make([
            'date' => $validated['date'],
            'hours' => $validated['hours'],
            'reason' => $validated['reason'],
            'comments' => $validated['comments']
        ]);

        $wh->user()->associate($user);
        $wh->area()->associate($area);
        $wh->approver()->associate($approver);

        return Redirect::route('workHours.index')->with('success', 'Work Hours saved');
    }

but I get an error about user_id not having a default value, which is true, since my understanding is that Eloquent handles assigning that. What I can do is make user_id, approver_id, and area_id fillable in the WorkHours model and save like this:

        $wh = WorkHours::create([
            'date' => $validated['date'],
            'hours' => $validated['hours'],
            'reason' => $validated['reason'],
            'comments' => $validated['comments'],
            'user_id' => $validated['user'],
            'approver_id' => $validated['approver'],
            'area_id' => $validated['area']
        ]);

and it works, but it is cloogy, and bypasses Eloquent.

1. Do I have my relationships set up properly for what I am trying to accomplish?
2. How do I need to store the records in my controller to properly use Eloquent?

Answer 1

My issue (as I suspected) was in a relationship definition. Once I changed the approval() definition in User from this

    public function approval()
    {
        return $this->belongsTo(WorkHours::class, 'approver_id');
    }

to this

    public function approvals()
    {
        return $this->haMany(WorkHours::class, 'approver_id');
    }

it worked fine. There was no user id value to write since the relationship for the approver was wrong, which was why it was looking for a default value.