$comment - Amazon DocumentDB
Example (MongoDB Shell)Code examples

$comment

The $comment operator in Amazon DocumentDB is used to attach a comment to a query. This can be useful for providing additional context or information about the query, which can be helpful for debugging or documenting purposes. The attached comment will appear as part of the output of operations like db.currentOp().

Parameters

  • string: The comment attached to the query.

Example (MongoDB Shell)

The following example demonstrates how to use the $comment operator in Amazon DocumentDB.

Create sample documents

db.users.insertMany([
  { name: "John Doe", age: 30, email: "john.doe@example.com" },
  { name: "Jane Smith", age: 25, email: "jane.smith@example.com" },
  { name: "Bob Johnson", age: 35, email: "bob.johnson@example.com" }
]);

Query example

db.users.find({ age: { $gt: 25 } }, { _id: 0, name: 1, age: 1 }).comment("Retrieve users older than 25");

Output

{ "name" : "John Doe", "age" : 30 }
{ "name" : "Bob Johnson", "age" : 35 }

Code examples

To view a code example for using the $comment command, choose the tab for the language that you want to use:

Node.js
const { MongoClient } = require('mongodb');

async function main() {
  const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  const db = client.db('test');
  const users = db.collection('users');

  const result = await users.find({ age: { $gt: 25 } }, { projection: { _id: 0, name: 1, age: 1 } })
                           .comment('Retrieve users older than 25')
                           .toArray();

  console.log(result);

  await client.close();
}

main();
Python
from pymongo import MongoClient

def main():
    client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
    db = client.test
    users = db.users

    result = list(users.find({ 'age': { '$gt': 25 }}, { '_id': 0, 'name': 1, 'age': 1 })
                .comment('Retrieve users older than 25'))

    print(result)

    client.close()

if __name__ == '__main__':
    main()