How can we modify documents?
Update operations modify the fields and values of a document while keeping other fields and values unchanged. Replace operations substitute all fields and values in an existing document with specified fields and values while keeping the _id field value unchanged.
The Node.js driver provides the following methods to change documents:
updateOne()
updateMany()
replaceOne()
The top level of an update document contains one or more of the following update operators:
$set: replaces the value of a field with a specified one
$inc: increments or decrements field values
$rename: renames fields
$unset: removes fields
$mul: multiplies a field value by a specified number