python - 如何在 get_or_create 中用另一个对象更新对象？

Question

我必须使用具有相似字段的表，并且我想将对象从一个表复制到另一个表。第二个表中可能没有对象的问题，所以我必须使用 get_or_create() 方法:

#these are new products, they all are instances of NewProduct model, which is similar
#to Product model
new_products_list = [<NewProduct: EEEF0AP>, <NewProduct: XR3D-F>,<Product: XXID-F>]

#loop over them and check if they are already in database
for product in new_products_list:
    product, created = Products.objects.get_or_create(article=product.article)

    if created:
       #here is no problem because new object saved 
       pass
    else:
       # here I need to code that will update existing Product instance
       # with values from NewProduct instance fields

情况是我不想像这样手动列出所有要更新的字段，因为我有大约 30 个字段:

update_old_product = Product(name=new_product.name,article= new_product.article)

请指教比上面更优雅的方式

Answer 1

您可以遍历字段名称并在另一个 Product 实例中更新它们:

for new_product in new_products_list:
    # use different variable names, otherwise you won't be able to access
    # the item from new_product_list here
    product, created = Products.objects.get_or_create(article=new_product.article)

    if not created:
       for field in new_product._meta.get_all_field_names():
           setattr(product, field, getattr(new_product, field))
       product.save()