Insert and Update Data - Python MongoDB

In MongoDB, insertion refers to adding new documents into a collection, while updating allows modifying existing documents. These operations are essential for managing dynamic datasets. With PyMongo library in Python, users can perform these tasks efficiently by establishing a connection to the database, creating or accessing collections and executing commands to insert or update data.

Insert data

Inserting data involves defining documents as dictionaries and adding them to a collection using insert_one() or insert_many(). Each inserted document automatically gets a unique _id field.

1. Use insert_one() for a single document.

collection.insert_one(doc1)

Parameter: doc1 represents a dictionary

2. Use insert_many() for multiple document.

collection.insert_many([doc1, doc2, doc3.....])

Parameter: [doc1, doc2, doc3,....] represents a list of dictionary

Viewing Inserted Documents

To view the inserted documents, MongoDB provides the find() method, which retrieves documents from a specific collection.

cursor = collection.find()
for doc in cursor:
print(doc)

Note:find() method works only within a single collection. It does not support querying across multiple collections simultaneously.

Let's see Example of Insertion of Data:- 

Output

Update data

Updating data involves modifying existing documents in a collection using update_one() or update_many(). These methods require a filter to match documents and an update operation to specify the changes.

With pymongo, updates can be easily applied using update operators like $set or $currentDate.

1. Use update_one() to update a single matching document

collection.update_one(filter, update)

Parameter:

• filter a dictionary specifying the condition to match documents (e.g., {"eid": 101})
• update a dictionary that defines the changes to apply (e.g., {"$set": {"name": "Updated Name"}})

2. Use update_many() to update all documents that match a condition

collection.update_many(filter, update)

Parameter:

• filter a dictionary specifying the matching criteria
• update a dictionary with update operators and values

Common Update Operators

1. $set: Updates the value of a specified field. If the field doesn't exist, it will be created.

{"$set": {"field": "value"}}

2. $currentDate: Sets the field to the current date or timestamp.

{"$currentDate": {"lastModified": True}}

Let's see Example of Updation of Data:- 

Output

To find number of documents or entries in collection that are updated, use:

print(result.matched_count)

Here output would be 1.

Related Articles:

• Insert Method
• Update Method
• Logical query operators
• Comparison query operators
• Projection Operators