The brain is already boiling, what's wrong here?

Question

PHP

Hi all. I have a problem with the code, it works, but it's very strange...
O_o // Upd. In the code example - using Phalcon
Suppose there is a table with such fields. Further, I will call it Sections

And now the task Suppose I need to put a category with ID
4 in place of category 3. Accordingly, category 3 will take the place of category 4. Everything seems to be simple ...
I decided to make the move as follows:
then 2 identical IDs cannot be. I so shall tell create temporary ID which is not present in the table yet. (The number of rows in the table + 1)
Next, for the category with ID 3, I change the ID to one that is not yet in the table.
Since the category with ID 4 has been vacated, I move category 3 to the place (replace ID).
Well, now the place has been freed up again from under category 4, so I move category 3 from the "time line" there.
It seems to be logical ...
In the form of code, it all looks like this:

public function upAction ($id = 0)
    {
        $allSections    = new Sections();
        $currentSection = $allSections->findFirstById($id);
        
        if (!$currentSection)
        {
            $this->flash->warning('Категория не найдена');
            return $this->response->redirect('dashboard-section');
        }
        
        /* <Костыль> */
        $numRows       = $allSections->find()->count();// Общее количество категорий
        $notDefineId   = ++$numRows;// ID которого ещё нет в таблице. Туда временно перенесём категорию Б
        $nearbySection = $allSections->findFirst([
            'conditions' => 'id != :current_section: AND id > :current_section:',
            'bind' => [
                'current_section' => $currentSection->id
            ]
        ]);// Ищем строку ближайшую к текущей. 
        
        
        if (!$nearbySection)
        {
            $this->flash->warning('Категория и так занимает первую позицию');
            return $this->response->redirect('dashboard-section');
        }
        
        $currentId = $currentSection->id;// ID категории А
        $nearbyId  = $nearbySection->id;// ID категории Б
        
        $nearbySection->id = $notDefineId;// Перемещаем категорию Б во временную строку
        $nearbySection->save();// Сохраняем
        
        $currentSection->id = $nearbyId;// ID категории А заменяем на ID категории Б
        $currentSection->save();// сохраняем
        
        $nearbySection->id = $currentId;// перенсим категорию Б из временной строки на место категории А
        $nearbySection->save();// сохраняем
        
        $this->flash->success('Категория успешно перемещена');
        /* </костыль> */
        
        return $this->response->redirect('dashboard-section');
    }

But when the method is called with the parameter: upAction(4) there is no movement, but cloning occurs ... That is, the lines do not change places. Line 3 turns into line 4 (Field values ​​become identical)
Here is a visual result of the work:

Actually, I think the question is already clear. Why is that? why are the lines not swapped? why does cloning happen?

Answer 1

It may be easier to use stupid sorting. additional field ord and store the sort index in it. as a more convenient solution for directories, I advise you to use nested sets