How to list the outer-most fields of a large document usign PyMongo?-CodePudding

I am just having difficulties to understand this, how can I list outer-most fields when I am working with a huge text datasets? I am trying to implement it in Mongodb and pymongo? any suggestions?

CodePudding user response：

I am not sure what you need, but maybe the bellow can help.

Query

this query returns an array with all the names of the outer fields
objectToArray to convert ROOT document to array
get the first member that is the field name

Test code here

aggregate(
[{"$project": 
    {"_id": 0,
      "outer-fields": 
      {"$map": 
        {"input": 
          {"$map": 
            {"input": {"$objectToArray": "$$ROOT"},
              "in": ["$$m.k", "$$m.v"],
              "as": "m"}},
          "in": {"$arrayElemAt": ["$$this", 0]}}}}}])