possible to store JSON scalar null instead of SQL NULL by using Value(None, JSONField()). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null org/3/library/stdtypes.html#dict], it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name="Max" data=None) # SQL NULL. >>> Dog.objects.create(name="Archie", data=Value(None, JSONField())) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects

possible to store JSON scalar null instead of SQL NULL by using Value(None, JSONField()). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null org/3/library/stdtypes.html#dict], it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name="Max" data=None) # SQL NULL. >>> Dog.objects.create(name="Archie", data=Value(None, JSONField())) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects

possible to store JSON scalar null instead of SQL NULL by using Value(None, JSONField()). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null org/3/library/stdtypes.html#dict], it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name="Max" data=None) # SQL NULL. >>> Dog.objects.create(name="Archie", data=Value(None, JSONField())) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects

possible to store JSON scalar null instead of SQL NULL by using Value(None, JSONField()). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null None is inside a list or dict, it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name="Max" data=None) # SQL NULL. >>> Dog.objects.create(name="Archie", data=Value(None, JSONField())) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects.

possible to store JSON scalar null instead of SQL NULL by using Value('null'). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null is the None is inside a list or dict, it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name='Max' create(name='Max', data=None) # SQL NULL. >>> Dog.objects.create(name='Archie', data=Value('null')) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects.

possible to store JSON scalar null instead of SQL NULL by using Value('null'). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null is the None is inside a list or dict, it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name='Max' create(name='Max', data=None) # SQL NULL. >>> Dog.objects.create(name='Archie', data=Value('null')) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects

install）：在项目目录下执行 npm install 命令，安装项目所需的前端 4 《51 测试天地》七十四 www.51testing.com 依赖包，这些依赖包通常存储在 package.json 文件中。 前端服务配置启动：在项目目录下执行 npm run serve 命令，启动前端开发服务器， 可以在浏览器中预览项目。 三、关键技术介绍 1、后端为什么要创建虚拟环境，创建虚拟环境可以达到什么效果？ 提供了一系列工具和功能，使得 构建 RESTful API 变得简单、灵活和高效。 DRF 的主要特点和功能包括： 序列化：DRF 提供了序列化器，可以将数据对象转换成 JSON 等格式，以便于在 API 中进行传输。同时，它也可以将传入的 JSON 数据反序列化为数据对象，便于在后端进行 处理。 视图：DRF 提供了各种视图类，用于处理 API 请求，并返回适当的响应。包括基于 函数的视图和基于类的视图，还有通用视图和视图集等。 支持各种认证和权限控制方式，可以保护 API 的安全性。 分页和过滤：DRF 提供了分页和过滤功能，便于处理大量数据和筛选查询结果。 强大的请求和响应处理：DRF 支持各种数据格式的请求和响应处理，包括 JSON、 XML、HTML 等。 API 文档生成：DRF 自带的 Browsable API 功能可以生成易于阅读和理解的 API 文档， 方便开发人员和团队的协作。 6 《51 测试天地》七十四

possible to store JSON scalar null instead of SQL NULL by using Value('null'). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null is the None is inside a list or dict, it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name='Max' create(name='Max', data=None) # SQL NULL. >>> Dog.objects.create(name='Archie', data=Value('null')) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects.

possible to store JSON scalar null instead of SQL NULL by using Value('null'). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null is the None is inside a list or dict, it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: 122 Chapter 3. Using Django create(name='Max', data=None) # SQL NULL. >>> Dog.objects.create(name='Archie', data=Value('null')) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects

possible to store JSON scalar null instead of SQL NULL by using Value('null'). Whichever of the values is stored, when retrieved from the database, the Python representation of the JSON scalar null is the None is inside a list or dict, it will always be interpreted as JSON null. When querying, None value will always be interpreted as JSON null. To query for SQL NULL, use isnull: >>> Dog.objects.create(name='Max' create(name='Max', data=None) # SQL NULL. >>> Dog.objects.create(name='Archie', data=Value('null')) # JSON null. >>> Dog.objects.filter(data=None) ]> >>> Dog.objects.