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

$max

The $max update operator updates a field's value only if the specified value is greater than the current field value. This operator is useful for maintaining maximum values across updates.

Parameters

  • field: The field to update.

  • value: The value to compare with the current field value.

Example (MongoDB Shell)

The following example demonstrates using the $max operator to update the highest recorded score for a player.

Create sample documents

db.scores.insertMany([
  { _id: 1, player: "Alice", highScore: 85 },
  { _id: 2, player: "Bob", highScore: 92 },
  { _id: 3, player: "Charlie", highScore: 78 }
])

Update example

db.scores.updateOne(
  { _id: 1 },
  { $max: { highScore: 95 } }
)

Result

The highScore field for Alice is updated to 95 because 95 is greater than the current value of 85.

{ "_id": 1, "player": "Alice", "highScore": 95 }

Code examples

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

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

async function example() {
  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 collection = db.collection('scores');

  const result = await collection.updateOne(
    { _id: 1 },
    { $max: { highScore: 95 } }
  );

  console.log(result);
  await client.close();
}

example();
Python
from pymongo import MongoClient

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

    result = collection.update_one(
        { '_id': 1 },
        { '$max': { 'highScore': 95 } }
    )

    print(result)
    client.close()

example()