appwrite/docs/examples/1.5.x/server-dart/examples/databases/create-relationship-attribute.md

import 'package:dart_appwrite/dart_appwrite.dart';

Client client = Client() .setEndpoint('https://cloud.appwrite.io/v1') // Your API Endpoint .setProject('<YOUR_PROJECT_ID>') // Your project ID .setKey('<YOUR_API_KEY>'); // Your secret API key

Databases databases = Databases(client);

AttributeRelationship result = await databases.createRelationshipAttribute( databaseId: '<DATABASE_ID>', collectionId: '<COLLECTION_ID>', relatedCollectionId: '<RELATED_COLLECTION_ID>', type: RelationshipType.oneToOne, twoWay: false, // (optional) key: '', // (optional) twoWayKey: '', // (optional) onDelete: RelationMutate.cascade, // (optional) );