DJANGO:如何创建复制模型对象的方法？

from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.CharField(max_length=100)
    published_date = models.DateField()

def clone_book(book_instance):
    # 创建一个新的Book实例
    new_book = Book()
    
    # 复制所有字段值
    for field in book_instance._meta.fields:
        if hasattr(book_instance, field.name):
            setattr(new_book, field.name, getattr(book_instance, field.name))
    
    # 保存新的Book实例到数据库
    new_book.save()
    
    return new_book

# 假设我们有一个Book实例
original_book = Book.objects.get(id=1)

# 复制这个实例
cloned_book = clone_book(original_book)

def clone_book(book_instance):
    new_book = Book()
    for field in book_instance._meta.fields:
        if hasattr(book_instance, field.name):
            if field.name != 'author':  # 假设author是外键
                setattr(new_book, field.name, getattr(book_instance, field.name))
    new_book.save()
    return new_book

def clone_book(book_instance):
    new_book = Book()
    for field in book_instance._meta.fields:
        if hasattr(book_instance, field.name):
            setattr(new_book, field.name, getattr(book_instance, field.js_name))
    new_book.custom_field = book_instance.custom_field  # 手动复制自定义字段
    new_book.save()
    return new_book