appwrite/docs/examples/1.8.x/server-kotlin/java/databases/decrement-document-attribute.md

import io.appwrite.Client;
import io.appwrite.coroutines.CoroutineCallback;
import io.appwrite.services.Databases;

Client client = new Client()
    .setEndpoint("https://<REGION>.cloud.appwrite.io/v1") // Your API Endpoint
    .setProject("<YOUR_PROJECT_ID>") // Your project ID
    .setSession(""); // The user session to authenticate with

Databases databases = new Databases(client);

databases.decrementDocumentAttribute(
    "<DATABASE_ID>", // databaseId
    "<COLLECTION_ID>", // collectionId
    "<DOCUMENT_ID>", // documentId
    "", // attribute
    0, // value (optional)
    0, // min (optional)
    "<TRANSACTION_ID>", // transactionId (optional)
    new CoroutineCallback<>((result, error) -> {
        if (error != null) {
            error.printStackTrace();
            return;
        }

        System.out.println(result);
    })
);