MongoDB Limit

Understand the idea

A positive limit sets the requested result size, while the server may return fewer matches. For deep pagination, repeatedly skipping large prefixes can be expensive; a keyset cursor based on ordered keys may be more suitable. Keep query limits validated and capped at the application boundary.

Where to try it

Use a local Python environment with pymongo and your own separate MongoDB lab server. Set the lab connection through the environment, as shown below. The online runner does not provide this server connection.

A worked example

import os
from pymongo import MongoClient
with MongoClient(os.environ["MONGODB_URI"], serverSelectionTimeoutMS=3000) as client:
    database = client["bhylu_python_lab"]
    collection = database["workshop_products"]
    for document in collection.find({}, {"name": 1, "stock": 1}).sort("_id", 1).limit(2):
        print(document)

Read the result

At most two documents are printed in ascending identifier order.

Try one change

Describe a next-page query using the last displayed identifier and explain how equal primary sort values would affect the cursor.

Local MongoDB lab

Install pymongo in your local virtual environment and run a separate MongoDB lab server. Set MONGODB_URI in the environment of the Python process. These examples use bhylu_python_lab and workshop_products; create a few lab products before read/update lessons. Network and server operations are not available in the restricted online runner. The snippets are syntax-checked, not claimed to have been executed against your server.