从一对多关系中删除记录

Question

I have 3 tables:

users

id
role
email
typable_id
typable_type

buyers

id
name
address
avatar
email
residential_id

residentials

id
name
city 
state

And here is my model that shows the relationship

User.php

public function typable()
{
  return $this->morphTo();
}

Buyer.php

public function residential()
{
  return $this->belongsTo(Residential::class);
}

public function user()
{
  return $this->morphMany(User::class, 'typable');
}

Residential.php

public function buyer()
{
  return $this->hasMany(Buyer::class);
}

If I want to delete the residential, all buyers from that residential need to be deleted. Same as users need to be deleted too when the buyers is deleted. How can I do that? This is what insides my Residential Controller for destroy function.

ResidentialController

public function destroy(Request $request) 
    {
        $residentials = Residential::find($request->input('id'));
        $residentials->id = $request->input('id');
        $residentials->name = $request->input('name');
        $residentials->delete($residentials);

        return response()->json($residentials);
    }

I have tried to put this code to delete the buyers (for users not yet) inside destroy() but nothing is changed for the buyers to be deleted. $buyers = Buyer::where('residential_id','=',$request->residential_id)->first(); $buyers->delete($buyers);

While this is the code that I managed to do if I want to delete the buyers, the users are deleted too.

BuyerController

public function destroy(Request $request)
{
  $users = User::where('email', '=', $request->email)->first();
  $buyers = Buyer::find($request->input('id'));
  $buyers->id = $request->input('id');
  $buyers->name = $request->input('name');
  $buyers->delete($buyers);
  $users->delete($users);

  return response()->json($buyers);
}

I hope there is someone to help and teach me the correct way.

Answer 1

You might want to register model events to handle that:

class Residential extends Model
{
    // Lets use plural form for a HasMany relationship.
    public function buyers()
    {
        return $this->hasMany(Buyer::class);
    }

    protected static function booted()
    {
        static::deleting(function ($user) {
            // I am using Higher Order Message, check this out: https://laravel.com/docs/8.x/collections#higher-order-messages
            $this->buyers->each->delete();
        });
    }
}


class Buyer extends Model
{
    // Lets use the plural form for a MorpMany relationship.
    public function users()
    {
        return $this->morphMany(User::class, 'typable');
    }

    protected static function booted()
    {
        static::deleting(function ($user) {
            $this->users->each->delete();
        });
    }
}

And you only have to remove a single object in your controller:

class ResidentialController
{
    public function destroy(Request $request)
    {
        $residential = Residential::findOrFail($request->input('id'));
    
        $residential->delete();

        // The framework is gonna automatically convert this to a JSON object. 
        return $residential;
    }
}

class BuyerController
{
    public function destroy(Request $request)
    {
        $buyer = Buyer::findOrFail($request->input('id'));
    
        $buyer->delete();

        // The framework is gonna automatically convert this to a JSON object. 
        return $buyer;
    }
}

Answer 2

Approach-1

you can override the delete function for any model.

//Residential.php
public function delete()
{
    $this->buyer->delete(); 
    return parent::delete();
}

//Buyer.php
public function delete()
{
    $this->user->delete(); 
    return parent::delete();
}

Now when you delete any Residential record, the chain will first delete any related user and then delete buyer and finally delete the Residential record.

Approach-2

You can use each() method to get all relating buyer and then get all relating user.

$residentials->buyer
->each(function ($b) {
    $b->user->each(function ($u) {
        $u->delete();
    });
    $b->delete();
});
$residentials->delete();