CODEWITHSUNDEEP
pythonmongodbmongoengine
imhans4305
imhans4305

Reputation: 697

Modifying DictField in multiple documents together stored in Mongodb using mongoengine

I am working with a mongo database model building using mongoengine. I want to modify DictField by the result created in another function

from flask_mongoengine import MongoEngine
import marshmallow_mongoengine as ma
db = MongoEngine()

class TestData(db.Document):
    name = db.StringField(max_length=50, required=True,unique=True)
    num1 = db.IntField()
    num2 = db.IntField()
    ml_proc = db.DictField()
    hum_proc = db.DictField()

class TestDataSchema(ma.ModelSchema):
    class Meta:
        model = TestData

The sample data in database will be like below

Sample Data

[{
    "name" : "david",
    "num1" : 5,
    "num2" : 4,
    "ml_proc": {"sm": 7, "prod":12}
},
{
    "name" : "john",
    "num1" : 1,
    "num2" : 4
},
{
    "name" : "dune",
    "num1" : 5,
    "num2" : 5,
    "ml_proc": {"sm": 7, "prod":15}
},
{
    "name" : "jan",
    "num1" : 3,
    "num2" : 4
}]

Out of 4 documents in sample data, 2nd and 4th document have missing field ml_proc. The fields in ml_proc are sm and prod which are created from fields num1 and num2 calculated in another function defined as

import pandas as pd
    def calc(data):
        data["sm"] = data["num1"].apply(lambda x : x+2)
        data["prod"] = data["num2"].apply(lambda x : x*2)
        return data

I know its weird to think why this function is necessary but this is a very simple one for my requirement. The number of documents I am handling will be thousands at a time. Thats why i used pandas dataframe for processing. So my doubt is how to update Dictfield in multiple documents using result generated from pandas data processing

Any help is appreciated, Thanks in advance

Database Note: Dont take too much conc on values. This is just a sample image.

enter image description here

Upvotes: 1

Views: 119

Answers (1)

R2D2
R2D2

Reputation: 10737

Maybe you need something like this:

db.collection.update({
   "ml_proc": {
     $exists: false
  }
 },
 [
  {
    $addFields: {
      ml_proc: {
        sm: {
          $sum: [
            "$num1",
            2
          ]
        },
        prod: {
          $sum: [
            "$num2",
            2
          ]
        }
       }
      }
    }
 ],
 {
  multi: true
})

Explained:

  1. Match only documents where "ml_proc" do not exist
  2. addFields the "ml_proc" calculated based on num1 & num2 from same document
  3. Update all matched documents with the missing field "ml_proc".

playground

Upvotes: 1

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