How to Check if a Document Exists with an ObjectID in MongoDB Using Python?

To check if a document exists in MongoDB using its ObjectId in Python, you can use the PyMongo library, which provides a Python interface to MongoDB. Here’s an example of how you can do this:

from pymongo import MongoClient
from bson import ObjectId

# Connect to MongoDB
client = MongoClient('mongodb://localhost:27017/')
db = client['your_database']
collection = db['your_collection']

# Define the ObjectId of the document you want to check
document_id = ObjectId('your_document_id')

# Check if the document exists
if collection.find_one({"_id": document_id}):
    print("Document exists")
else:
    print("Document does not exist")

In this example, we first import the necessary modules from PyMongo (MongoClient and ObjectId). Then, we establish a connection to your MongoDB server, specifying the appropriate connection string and database and collection names.

Next, we define the document_id variable with the ObjectId of the document you want to check. Replace 'your_document_id' with the actual ObjectId you want to verify.

Finally, we use the find_one() method on the collection to search for a document with the specified ObjectId. If the document is found (i.e., the find_one() method returns a non-null result), we print “Document exists.” Otherwise, we print “Document does not exist.”

Make sure to replace 'your_database' and 'your_collection' with the actual names of your database and collection in MongoDB.

By using these steps, you can check if a document exists in MongoDB based on its ObjectId using Python and the PyMongo library.