Services or capabilities described in AWS documentation might vary by Region. To see the differences applicable to the AWS European Sovereign Cloud Region, see the AWS European Sovereign Cloud User Guide.$toLower
The $toLower operator in Amazon DocumentDB is used to convert a string to lowercase.
Parameters
Example (MongoDB Shell)
The following example demonstrates how to use the $toLower operator to convert the Desk field to lowercase.
Create sample documents
db.locations.insertMany([
{ "_id": 1, "Desk": "Düsseldorf-BVV-021" },
{ "_id": 2, "Desk": "Munich-HGG-32a" }
]);
Query example
db.locations.aggregate([
{ $project: { item: { $toLower: "$Desk" } } }
]);
Output
{ "_id" : 1, "item" : "düsseldorf-bvv-021" }
{ "_id" : 2, "item" : "munich-hgg-32a" }
Code examples
To view a code example for using the $toLower 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("locations");
const result = await collection.aggregate([
{ $project: { item: { $toLower: "$Desk" } } }
]).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["locations"]
result = list(collection.aggregate([
{ "$project": { "item": { "$toLower": "$Desk" } } }
]))
print(result)
client.close()
if __name__ == "__main__":
main()