$[] - Amazon DocumentDB
Example (MongoDB Shell)Code examples
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$[]

The $[] all positional operator updates all elements in an array. It is used when you need to modify every element in an array field.

Parameters

  • field.$[]: The array field with the all positional operator to update all elements.

Example (MongoDB Shell)

The following example demonstrates using the $[] operator to update all array elements.

Create sample documents

db.products.insertOne({
  _id: 1,
  name: "Laptop",
  prices: [1000, 1100, 1200]
});

Query example

db.products.updateOne(
  { _id: 1 },
  { $inc: { "prices.$[]": 50 } }
);

Output

{
  "_id" : 1,
  "name" : "Laptop",
  "prices" : [ 1050, 1150, 1250 ]
}

Code examples

To view a code example for using the $[] operator, choose the tab for the language that you want to use:

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

async function updateDocument() {
  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('products');

  await collection.updateOne(
    { _id: 1 },
    { $inc: { "prices.$[]": 50 } }
  );

  const updatedDocument = await collection.findOne({ _id: 1 });
  console.log(updatedDocument);

  await client.close();
}

updateDocument();
Python
from pymongo import MongoClient

def update_document():
    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.products

    collection.update_one(
        {'_id': 1},
        {'$inc': {'prices.$[]': 50}}
    )

    updated_document = collection.find_one({'_id': 1})
    print(updated_document)

    client.close()

update_document()