Python MongoDB - Update_many Query

Last Updated : 02 Jul, 2025

In PyMongo, the update_many() method is used to update multiple documents in a collection that match a given filter condition. It’s a powerful method when you need to make bulk updates to documents based on a shared field value or pattern.

Syntax

collection.update_many(
filter,
update,
upsert=False,
array_filters=None,
collation=None,
hint=None
)

Parameters:

Parameter	Type	Description
filter	dict	Query to match documents for update.
update	dict	Update operations (e.g., $set, $inc).
upsert	bool (optional)	Insert if no document matches. Default is False.
array_filters	list (optional)	Conditions to update specific array elements.
collation	Collation (optional)	Language rules for string comparison.
hint	dict or str (optional)	Index to optimize query performance.

Here is our sample data:

Python

from pymongo import MongoClient

c = MongoClient("mongodb://localhost:27017/")
db = c['companyDB']
col = db['employees']

data = [
    {"_id": 1, "name": "Alice", "department": "HR", "salary": 30000},
    {"_id": 2, "name": "Bob", "department": "Engineering", "salary": 50000},
    {"_id": 3, "name": "Charlie", "department": "Engineering", "salary": 48000},
    {"_id": 4, "name": "David", "department": "HR", "salary": 32000},
    {"_id": 5, "name": "Eve", "department": "Marketing", "salary": 40000}
]

col.delete_many({})
col.insert_many(data)
print("Data inserted.")

Output

Data inserted.

Explanation:

MongoClient() connects to the local server and accesses companyDB.employees.
insert_many(data) inserts sample employee records.
delete_many({}) ensures no duplicate data from previous runs.

Examples

Example 1: Increase salary by 10% for all Engineering department employees

Python

from pymongo import MongoClient

c = MongoClient("mongodb://localhost:27017/")
db = c['companyDB']
col = db['employees']

res = col.update_many(
    {"department": "Engineering"},
    { "$mul": { "salary": 1.1 } }  # multiply salary by 1.1 (10% raise)
)

print(f"Matched: {res.matched_count}, Modified: {res.modified_count}")

Output

Explanation: Matches all documents where department is "Engineering". $mul increases salary by 10% and update_many modifies all matching documents.

Example 2: Set a status field to "Active" for all employees in HR

Python

from pymongo import MongoClient

c = MongoClient("mongodb://localhost:27017/")
db = c['companyDB']
col = db['employees']
res = col.update_many(
    {"department": "HR"},
    { "$set": { "status": "Active" } }
)

print(f"Matched: {res.matched_count}, Modified: {res.modified_count}")

Output

Matched: 2, Modified: 2

Explanation: Adds a new field status and sets its value to "Active" for HR employees and $set is used to update/add a field.

Example 3: Remove the "salary" field from all Marketing department employees

Python

from pymongo import MongoClient

c = MongoClient("mongodb://localhost:27017/")
db = c['companyDB']
col = db['employees']

res = col.update_many(
    {"department": "Marketing"},
    { "$unset": { "salary": "" } }
)

print(f"Matched: {res.matched_count}, Modified: {res.modified_count}")

Output

Matched: 1, Modified: 1

Explanation: $unset removes the specified field from the document.

MongoDB Python - Insert and Replace Operations

Aadhar Tyagi

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Python MongoDB - Update_many Query

Syntax

Here is our sample data:

Examples

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