这里是示例文档:
{"id":1,
"info":{"age":10,"grade":80,"address":"LA"}
}
我做了什么:
# query the document
student = Student.objects(id=1).first()
# change the info
student.info['address'] = None
# save the change
studen.save()
[当我查看数据库时,此文档缺少地址字段。信息是{“ age”:10,“ grade”:80}为什么save()操作会自动错过null字段,如何避免呢?(我知道使用update可以保留null字段,但是我可以使用save并仍然保留null字段吗?)
您可以尝试给它Nan
或空字符串""
student.info = {"age":10,"grade":80,"address":""}
或
student.info = {"age":10,"grade":80,"address":Nan}