Laravel Save许多在复制模型上删除了旧关系

Question

我使用Laravel 5.7，我想复制一个模型及其所有关系。

我使用以下代码：

$selection = json_decode($request->get('selection'));
$products = Product::find($selection);

foreach ($products as $product) {
    // copy attributes
    $new = $product->replicate();

    // save model before you recreate relations (so it has an id)
    $new->name = $product->name .' - new';
    $new->push();

    // copy relations - it works for this one
    foreach($product->typeProductsTags as $typeProductTag) {
        $new->typeProductsTags()->attach($typeProductTag);
    }

    // promotions is an array of model
    $promotions = $product->promotions;
    if ($promotions) {
        // it erases promotions of product with the ID of the new model
        $new->promotions()->saveMany($promotions);
    }
}

它适用于belongsToMany关系，但是对于$promotions，它仅擦除现有关系的外键，用新的ID替换当前的产品ID。

$product->promotions是hasMany()关系。

如何在不失去原始关系的情况下复制这种关系？

编辑

好吧，看来您必须复制所有关系，此代码有效：

// save promotions
$promotions = $product->promotions;
if ($promotions) {
    $promotionsNew = [];
    foreach ($promotions as $promotion) {
        $promotionNew =  $promotion->replicate();
        $promotionNew->save();

        $promotionsNew []= $promotionNew;
    }
    $new->promotions()->saveMany($promotionsNew);
}