$split

The $split aggregation operator in Amazon DocumentDB is used to split a string into an array of substrings, based on a specified delimiter. This can be useful for parsing complex string fields and extracting individual components for further processing.

Parameters

• string: The string to be split.

• delimiter: The character or string used to split the input string.

Example (MongoDB Shell)

In this example, we use $split to separate the components of a "Desk" field into an array, making it easier to process the data.

Create sample documents

db.people.insertMany([
  { "_id": 1, "Desk": "Düsseldorf-BVV-021" },
  { "_id": 2, "Desk": "Munich-HGG-32a" },
  { "_id": 3, "Desk": "Cologne-ayu-892.50" },
  { "_id": 4, "Desk": "Dortmund-Hop-78" }
]);

Query example

db.people.aggregate([
  { $project: { parts: { $split: ["$Desk", "-"] } } }
]);

Output

{ "_id" : 1, "parts" : [ "Düsseldorf", "BVV", "021" ] }
{ "_id" : 2, "parts" : [ "Munich", "HGG", "32a" ] }
{ "_id" : 3, "parts" : [ "Cologne", "ayu", "892.50" ] }
{ "_id" : 4, "parts" : [ "Dortmund", "Hop", "78" ] }

The output of $split creates an array that can be used in the application to display the information for the employees.

Code examples

To view a code example for using the $split 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 result = await db.collection('people').aggregate([
    { $project: { parts: { $split: ['$Desk', '-'] } } }
  ]).toArray();
  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
    result = list(db.people.aggregate([
        { '$project': { 'parts': { '$split': ['$Desk', '-'] } } }
    ]))
    print(result)
    client.close()

example()