Python 如何在get_或create中使用另一个对象更新对象？

我必须创建具有类似字段的表，并且要将对象从一个表复制到另一个表。 问题是第二个表中可能缺少对象，所以我必须使用get\u或\u create（）方法：

---

请建议使用比上面更优雅的方式

您可以尝试这样的方式

def copy_fields(frm, to):
    id = to.id
    for field in frm.__class__._meta.fields:
        setattr(to, field.verbose_name, field._get_val_from_obj(frm))
    to.id = id

---

您可以在字段名称上循环，并在另一个

产品

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()

---

这类似于Ashwini Chaudhary，尽管我认为它会处理您在评论中提到的错误

new_products_list= (
#   obj1, obj2, obj3 would be from [<NewProduct: EEEF0AP>, <NewProduct: XR3D-F>,<Product: XXID-F>] in your question
#   NewProduct would just be the model that you import
#   NewProduct._meta.fields would be all the fields
    (obj1, NewProduct, NewProduct._meta.fields,),
    (obj2, NewProduct, NewProduct._meta.fields,),
    (obj3, NewProduct, NewProduct._meta.fields,),
)

for instance, model, fields in new_products_list:
    new_fields = {}
    obj, created = model.objects.get_or_create(pk=instance.article) # this is pretty much just here to ensure that it is created for filter later
    for field in fields:
        if field != model._meta.pk: # do not want to update the pk
            new_fields[field.name] = request.POST[field.name]
    model.objects.filter(pk=question_id).update(**new_fields) # you won't have to worry about updating multiple models in the db because there can only be one instance with this pk

新产品列表=(
#在你的问题中，obj1，obj2，obj3来自[，]
#新产品就是您导入的模型
#NewProduct.\u meta.fields将是所有字段
（obj1，NewProduct，NewProduct.\u元字段，），
（obj2，NewProduct，NewProduct.\u元字段，），
（obj3，NewProduct，NewProduct.\u元字段，），
)
例如，模型、新产品列表中的字段：
新的_字段={}
obj，created=model.objects.get_或_create（pk=instance.article）#这里的内容主要是为了确保为以后的筛选创建它
对于字段中的字段：
如果是字段！=型号。_meta.pk:#不想更新pk
新字段[field.name]=request.POST[field.name]
model.objects.filter（pk=question_id）.update（**new_fields）#您不必担心更新数据库中的多个模型，因为只有一个实例具有此pk

---

我知道这是一个多月前的事了，但我想我会分享我的解决方案，即使你已经弄明白了

那太好了，但是当我输入

product.save（）

时，我得到了这样一个错误

IntegrityError:（1062，“重复输入'2326209_FARNELL'作为键'product_article_4b591bee1bc47d02_uniq'）

您的新产品中可能有一个字段包含重复的值。文章字段中出现错误，但它是唯一的，因此引发该错误，因为ORM试图创建相同的对象，而不是更新现有的对象。那么，我如何才能真正触发更新而不是创建？

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()

new_products_list= (
#   obj1, obj2, obj3 would be from [<NewProduct: EEEF0AP>, <NewProduct: XR3D-F>,<Product: XXID-F>] in your question
#   NewProduct would just be the model that you import
#   NewProduct._meta.fields would be all the fields
    (obj1, NewProduct, NewProduct._meta.fields,),
    (obj2, NewProduct, NewProduct._meta.fields,),
    (obj3, NewProduct, NewProduct._meta.fields,),
)

for instance, model, fields in new_products_list:
    new_fields = {}
    obj, created = model.objects.get_or_create(pk=instance.article) # this is pretty much just here to ensure that it is created for filter later
    for field in fields:
        if field != model._meta.pk: # do not want to update the pk
            new_fields[field.name] = request.POST[field.name]
    model.objects.filter(pk=question_id).update(**new_fields) # you won't have to worry about updating multiple models in the db because there can only be one instance with this pk