[5.8] Fix BelongsToMany read wrong parent key.

[tinpont]

Sometimes we don't have primary id in pivot table. For example:
I have three tables.

// users
[{
    id: 1,
    uuid: "c3b5c66a-aebe-4c76-9a51-9c305ff6dad1",
    name: "John"
}]

// shops
[{
    id: 1,
    uuid: "25adf508-8dff-4a7f-ad26-3320f4d23f15",
    name: "Nice Pizza"
}, {
    id: 1,
    uuid: "84a11000-0a09-4054-bc9c-c4e49e2f48c5",
    name: "Nice Flower"
}]

// user_shop(pivot table)
[{
    user_uuid: "c3b5c66a-aebe-4c76-9a51-9c305ff6dad1",
    shop_uuid: "25adf508-8dff-4a7f-ad26-3320f4d23f15"
}]

User extends Eloquent\Model

    /**
     * Has many shops
     *
     * @return \Illuminate\Database\Eloquent\Relations\BelongsToMany
     */
    public function shops()
    {
        return $this->belongsToMany(Shop::class, 'user_shop', 'user_uuid',
            'shop_uuid', 'uuid', 'uuid')
            ->using(UserShop::class);
    }

UserShop extends Eloquent\Relations\Pivot

// Empty

<?php
    $user = \App\Models\User::first();
    $user->shops()->sync(['84a11000-0a09-4054-bc9c-c4e49e2f48c5']);
    dd($user->shops->toArray());

expect

delete from `user_shop` where (`user_uuid` = 'c3b5c66a-aebe-4c76-9a51-9c305ff6dad1' and `shop_uuid` = '25adf508-8dff-4a7f-ad26-3320f4d23f15')

actual

delete from `user_shop` where (`user_uuid` = 1 and `shop_uuid` = '25adf508-8dff-4a7f-ad26-3320f4d23f15')

Because user_uuid read $this->parent->getKey().

[driesvints]

Shouldn't it be the following instead? (actual shop uuid)

delete from `user_shop` where (`user_uuid` = 'c3b5c66a-aebe-4c76-9a51-9c305ff6dad1' and `shop_uuid` = '25adf508-8dff-4a7f-ad26-3320f4d23f15')

Your examples are a little confusing since you use twice the same primary key and uuid for your shop records.

Can you paste your full user and shop model?

[driesvints]

@staudenmeir can you maybe confirm this pr?

[tinpont]

@driesvints Sorry for my typo. Actually the first shop uuid is '25adf508-8dff-4a7f-ad26-3320f4d23f15';

Here is my full Models.

User

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public $timestamps = false;
    
    public function shops()
    {
        return $this->belongsToMany(Shop::class, 'user_shop', 'user_uuid',
            'shop_uuid', 'uuid', 'uuid')
            ->using(UserShop::class);
    }
}

Shop

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Shop extends Model
{
    public $timestamps = false;
}

UserShop

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Relations\Pivot;

class UserShop extends Pivot
{
}

You can also run the test case to reproduce this bug.