mongodb update item in an object isnt working as expected

Question

I am using python with mongodb in the backend. my data looks like that:

data = {"_id": ObjectId("anything", "x": {"one": "number", "two": "number"})}

I am trying to update all values in x that meet a certain condition. Here is what i am trying:

col.update( {"x.one": "number"}, {"$set": {"x.onnneeee": "number"}}, multi=True)
col.update_many( {"x.one": "number"}, {"$set": {"x.onnneeee": "number"}})

However, After checking the database. I see the new value is being added to the end of the "x" object while the object {"x.one": "number"} isnt being changed. any explanation why this is happening?

Answer 1

Use $unset in the same update dict to unset x.one

col.update( {"x.one": "number"}, {"$set": {"x.onnneeee": "number"}, "$unset": {"x.one": ""}}, multi=True)

The first arg {"x.one": "number"} is just a filter query and identifies records which are to be updated. The 2nd arg sets what updates to perform on the selected records