然后

 

报错：

NotImplementedError at /shopcarts/1/

`update()` must be implemented.

Request Method: 	PUT
Request URL: 	http://127.0.0.1:8000/shopcarts/1/
Django Version: 	1.11.6
Exception Type: 	NotImplementedError
Exception Value: 	

`update()` must be implemented.

Exception Location: 	D:\Envs\MxShop\lib\site-packages\rest_framework\serializers.py in update, line 166
Python Executable: 	D:\Envs\MxShop\Scripts\python.exe
Python Version: 	3.6.0
Python Path: 	

['C:\\Users\\huang\\PycharmProjects\\MxShop\\extra_apps',
 'C:\\Users\\huang\\PycharmProjects\\MxShop\\apps',
 'C:\\Users\\huang\\PycharmProjects\\MxShop',
 'C:\\Users\\huang\\PycharmProjects\\MxShop',
 'C:\\Program Files\\JetBrains\\PyCharm 2018.2.4\\helpers\\pydev',
 'C:\\Users\\huang\\PycharmProjects\\MxShop',
 'C:\\Users\\huang\\PycharmProjects\\MxShop\\apps',
 'C:\\Users\\huang\\PycharmProjects\\MxShop\\extra_apps',
 'C:\\Program Files\\JetBrains\\PyCharm 2018.2.4\\helpers\\pydev',
 'C:\\Users\\huang\\.PyCharm2018.2\\system\\cythonExtensions',
 'D:\\Envs\\MxShop\\Scripts\\python36.zip',
 'C:\\Users\\huang\\AppData\\Local\\Programs\\Python\\Python36\\DLLs',
 'C:\\Users\\huang\\AppData\\Local\\Programs\\Python\\Python36\\lib',
 'C:\\Users\\huang\\AppData\\Local\\Programs\\Python\\Python36',
 'D:\\Envs\\MxShop',
 'D:\\Envs\\MxShop\\lib\\site-packages',
 'D:\\Envs\\MxShop\\lib\\site-packages\\setuptools-39.1.0-py3.6.egg',
 'C:\\Program Files\\JetBrains\\PyCharm '
 '2018.2.4\\helpers\\pycharm_matplotlib_backend']

Server time: 	星期六, 11 五月 2019 19:03:36 +0800

 

解决办法：

 

    def update(self, instance, validated_data):
        # 修改商品数量
        instance.nums = validated_data["nums"]
        instance.save()
        return instance

 

 

再 put一次 修改成功

 

删除功能也能实现