[8.x] Fix qualified column in withAggregate

[dbakan]

This PR fixes a QueryException when using the new Builder features withAggregate, withMin, withSum, etc.

When using User::withMin('roles', 'id') on a belongsToMany relation the current implementation creates a query like

select users.*, (select min(`id`) from roles inner join role_user on ...) as ...

which can cause an SQL error:

SQLSTATE[23000]: Integrity constraint violation: 1052 Column 'id' in field list is ambiguous

This PR passes the $column through $relation->getRelated()->qualifyColumn($column) to ensure fully qualified names:

select users.*, (select min(`roles`.`id`) from roles inner join role_user on ...) as ...

[khalilst]

@dbakan
I have test your idea and there was not SQL error:

>>> Product::withMin('comments', 'id')->get()
=> Illuminate\Database\Eloquent\Collection {#3241
     all: [
       App\Models\Product {#4119
         id: 1,
         name: "fSbKRoIpBl",
         created_at: "2020-11-02 09:48:39",
         updated_at: "2020-11-02 09:48:39",
         comments_min_id: 1,
       },
       App\Models\Product {#3249
         id: 2,
         name: "TBpEYufkJI",
         created_at: "2020-11-02 09:48:39",
         updated_at: "2020-11-02 09:48:39",
         comments_min_id: 3,
       },
       App\Models\Product {#4185
         id: 3,
         name: "iBlkWmyfU3",
         created_at: "2020-11-02 09:48:39",
         updated_at: "2020-11-02 09:48:39",
         comments_min_id: 7,
       },
       App\Models\Product {#3557
         id: 4,
         name: "c0o1InKesx",
         created_at: "2020-11-02 09:48:47",
         updated_at: "2020-11-02 09:48:47",
         comments_min_id: 5,
       },
     ],
   }

This is the raw SQL:

>>> Product::withMin('comments', 'id')->toSql()
=> "select `products`.*, (select min(`id`) from `comments` where `products`.`id` = `comments`.`commentable_id` and `comments`.`commentable_type` = ? limit 1) as `comments_min_id` from `products`"

[dbakan]

@khalilst There is no join happening in your SQL.

// migration to create the role_user table:
Schema::create('role_user', function (Blueprint $table) {
    $table->id(); // this will be the ambiguous column
    $table->foreignId('user_id');
    $table->foreignId('role_id');

    $table->unique(['user_id', 'role_id']);
});

// relation on User model
public function roles()
{
    return $this->belongsToMany('App\Models\Role');
}

>>> User::withMin('roles', 'id')->toSql();
select `users`.*, (select min(`id`) from `roles` inner join `role_user` on `roles`.`id` = `role_user`.`role_id` where `users`.`id` = `role_user`.`user_id` limit 1) as `roles_min_id` from `users`

I know that you might drop the column role_user.id in this example, but of cause it also happens with other columns in the pivot table like created_at.

[khalilst]

@dbakan Right, thanks for clarifying.