Update all Documents in a Collection using PyMongo (original) (raw)

Last Updated : 12 Jul, 2025

MongoDBis an open-source document-oriented database. MongoDB stores data in the form of key-value pairs and is a NoSQL database program. The term NoSQL means non-relational.

PyMongo contains tools which are used to interact with the MongoDB database. Now let's see how to update all the documents in a collection.

Updating all Documents in a Collection

PyMongo includes an update_many() function which updates all the documents which satisfy the given query.

update_many() accepts the following parameters -

1. filter - It is the first parameter which is a criteria according to which the documents that satisfy the query are updated.
2. update operator- It is the second parameter which contains the information to be updated in the documents.
3. upsert- (Optional) It is a boolean. If set to true and there is no document matching the filter, a new document is created.
4. array_filters - (Optional) It is an array of filter documents to determine which array elements to modify for an update operation on an array field.
5. bypass_document_validation - (Optional) A boolean which skips the document validation when set to True.
6. collation - (Optional) specifies the language specific rules for the operation.
7. session - (Optional) a ClientSession.

Update Operators in MongoDB

Setting Values:

• $set: Used to set a fields value.
• $setOnInsert: Update value only if a new document insertion.
• $unset: Remove the field and its value.

Numeric Operators:

• $inc: Increases the value by a given amount.
• $min/$max: returns minimum or maximum of value.
• $mul: multiplies the values by a given amount.

Miscellaneous Operators:

• $currentDate: Updates value of a field to current date.
• $rename: Renames a field

Now let's understand through some examples.

Sample Database:

Screenshot of Database from Compass

Some use cases we are going to see in this article where updating many records can be useful:

1. Changing or incrementing several elements based on a condition.
2. Inserting a new field to multiple or all documents.

Example 1: All the students with marks greater than 35 has been passed.

Python3 `

from pymongo import MongoClient

Creating an instance of MongoClient

on default localhost

client = MongoClient('mongodb://localhost:27017')

Accessing desired database and collection

db = client.gfg collection = db["classroom"]

Update passed field to be true for all

students with marks greater than 35

collection.update_many( {"marks": { "$gt": "35" } }, { "$set": { "passed" : "True" } } )

`

Database After Query:

Pass field has been updated to true for student 1 and 3

Example 2: New field called address added to all documents

Python `

from pymongo import MongoClient

Creating an instance of MongoClient

on default localhost

client = MongoClient('mongodb://localhost:27017')

Accessing desired database and collection

db = client.gfg collection = db["classroom"]

Address filed to be added to all documents

collection.update_many( {}, {"$set": { "Address": "value" } },

don't insert if no document found

upsert=False, array_filters=None )

`

Database After query:

Address field has been added to all documents.