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

$toBool

The $toBool operator in Amazon DocumentDB converts an expression to a boolean value.

Parameters

  • expression: The expression to be converted to a boolean value.

Note: Any string converts to true.

Example (MongoDB Shell)

The following example demonstrates using the $toBool operator to normalize device state values from different data types.

Create sample documents

db.deviceStates.insertMany([
  { _id: 1, deviceId: "sensor-001", status: true },
  { _id: 2, deviceId: "camera-002", status: 1 },
  { _id: 3, deviceId: "thermostat-003", status: "active" },
  { _id: 4, deviceId: "doorlock-004", status: 0 }
]);

Query example

db.deviceStates.aggregate([
  {
    $project: {
      _id: 1,
      deviceId: 1,
      isActive: { $toBool: "$status" }
    }
  }
]);

Output

[
  { "_id": 1, "deviceId": "sensor-001", "isActive": true },
  { "_id": 2, "deviceId": "camera-002", "isActive": true },
  { "_id": 3, "deviceId": "thermostat-003", "isActive": true },
  { "_id": 4, "deviceId": "doorlock-004", "isActive": false }
]

Code examples

To view a code example for using the $toBool 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 collection = db.collection('deviceStates');

  const result = await collection.aggregate([
    {
      $project: {
        _id: 1,
        deviceId: 1,
        isActive: { $toBool: '$status' }
      }
    }
  ]).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']
    collection = db['deviceStates']

    result = list(collection.aggregate([
        {
            '$project': {
                '_id': 1,
                'deviceId': 1,
                'isActive': { '$toBool': '$status' }
            }
        }
    ]))

    print(result)

    client.close()

if __name__ == '__main__':
    main()