DataStore.save() fails when a field used as a partition key is left empty

[justkj7]

Description

I deployed my stack in remote server already using amplify init && amplify push
However, when DataStore.save() is invoked, it seems local db is updated but db in remote server is not updated correspondingly.

Here is amplify status using the command.

$ amplify status

    Current Environment: dev
    
┌──────────┬───────────────┬───────────┬───────────────────┐
│ Category │ Resource name │ Operation │ Provider plugin   │
├──────────┼───────────────┼───────────┼───────────────────┤
│ Api      │ chatservice   │ Update    │ awscloudformation │
└──────────┴───────────────┴───────────┴───────────────────┘

GraphQL endpoint: xxxx
GraphQL API KEY: xxxx

GraphQL transformer version: 2

Categories

• Analytics
• API (REST)
• API (GraphQL)
• Auth
• Authenticator
• DataStore
• Storage

Steps to Reproduce

1. configure schema.graphql as following

type Room @model @auth(rules: [{allow: public}]) {
  id: ID! @index(name: "roomIdOnCreatedAt", sortKeyFields: ["createdAt"], queryField: "roomIdOnCreatedAt")
  name: String!
  Messages: [Message] @hasMany(indexName: "byRoom", fields: ["id"])
  createdAt: AWSDateTime
}

type Message @model @auth(rules: [{allow: public}]) {
  id: ID!
  content: String!
  username: String
  roomID: ID! @index(name: "byRoom", sortKeyFields: ["createdAt"], queryField: "byRoomCreatedAt")
  createdAt: AWSDateTime
}

2. Setup amplify client as following

class _MyAppState extends State<MyApp> {
  final AmplifyDataStore _dataStorePlugin = AmplifyDataStore(
    modelProvider: ModelProvider.instance,
  );
  final AmplifyAPI _apiPlugin =
      AmplifyAPI(modelProvider: ModelProvider.instance);

  bool _isLoading = true;

  @override
  initState() {
    super.initState();
    _configureAmplify();
  }

  Future<void> _configureAmplify() async {
    // await Amplify.addPlugin(AmplifyAPI()); // UNCOMMENT this line after backend is deployed
    try {
      await Amplify.addPlugins([_dataStorePlugin, _apiPlugin]);

      // Once Plugins are added, configure Amplify
      await Amplify.configure(amplifyconfig);
    } catch (e) {
      print(e);
    }

    setState(() {
      _isLoading = false;
    });
  }
...

3. Invoke save()

      Room newRoom = Room(
        name: _tfNameController.text,
      );
      await Amplify.DataStore.save(newRoom);

4. Check new record saved in remote server

Screenshots

No response

Platforms

• iOS
• Android

Android Device/Emulator API Level

No response

Environment

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.5.3, on macOS 12.4 21F79 darwin-x64, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[✓] Xcode - develop for iOS and macOS
[✓] Chrome - develop for the web
[✓] Android Studio (version 3.5)
[✓] VS Code (version 1.67.2)
[✓] Connected device (2 available)

• No issues found!

Dependencies

- cross_file 0.3.3+1 [js meta]
- crypto 3.0.2 [typed_data]
- csslib 0.17.2 [source_span]
- date_time_format 2.0.1
- diffutil_dart 3.0.0
- equatable 2.0.3 [collection meta]
- ffi 1.2.1
- flutter_chat_types 3.2.1 [equatable json_annotation meta]
- flutter_link_previewer 2.6.1 [flutter flutter_chat_types flutter_linkify html http linkify meta url_launcher]
- flutter_linkify 5.0.2 [flutter linkify]
- flutter_plugin_android_lifecycle 2.0.6 [flutter]
- flutter_web_plugins 0.0.0 [flutter js characters collection meta typed_data vector_math]
- html 0.15.0 [csslib source_span]
- http 0.13.4 [async http_parser meta path]
- http_parser 4.0.1 [collection source_span string_scanner typed_data]
- image_picker_android 0.8.4+13 [flutter flutter_plugin_android_lifecycle image_picker_platform_interface]
- image_picker_for_web 2.1.8 [flutter flutter_web_plugins image_picker_platform_interface]
- image_picker_ios 0.8.4+11 [flutter image_picker_platform_interface]
- image_picker_platform_interface 2.5.0 [cross_file flutter http plugin_platform_interface]
- js 0.6.3
- json_annotation 4.5.0 [meta]
- linkify 4.1.0
- meta 1.7.0
- path 1.8.0
- photo_view 0.13.0 [flutter]
- plugin_platform_interface 2.1.2 [meta]
- sky_engine 0.0.99
- source_span 1.8.1 [collection path term_glyph]
- string_scanner 1.1.0 [charcode source_span]
- term_glyph 1.2.0
- typed_data 1.3.0 [collection]
- url_launcher 6.1.2 [flutter url_launcher_android url_launcher_ios url_launcher_linux url_launcher_macos url_launcher_platform_interface url_launcher_web url_launcher_windows]
- url_launcher_android 6.0.14 [flutter url_launcher_platform_interface]
- url_launcher_ios 6.0.14 [flutter url_launcher_platform_interface]
- url_launcher_linux 3.0.1 [flutter url_launcher_platform_interface]
- url_launcher_macos 3.0.1 [flutter url_launcher_platform_interface]
- url_launcher_platform_interface 2.0.5 [flutter plugin_platform_interface]
- url_launcher_web 2.0.7 [flutter flutter_web_plugins url_launcher_platform_interface]
- url_launcher_windows 3.0.1 [flutter url_launcher_platform_interface]
- uuid 3.0.6 [crypto]
- vector_math 2.1.0

Device

iPhone SE - 3rd generation

OS

iOS 15.5

CLI Version

8.3.1

Additional Context

No response

[Jordan-Nelson]

Hello @justkj7 - can you confirm you have conflict resolution enabled? You can view the conflict resolution strategy in amplify/backend/api/{project}/cli-inputs.json.

[justkj7]

Hi @Jordan-Nelson Yes. Here is snippet for conflict resolution in cli-inputs.json.

    "conflictResolution": {
      "defaultResolutionStrategy": {
        "type": "AUTOMERGE"
      },
      "perModelResolutionStrategy": [
        {
          "resolutionStrategy": {
            "type": "AUTOMERGE"
          },
          "entityName": "Room"
        },
        {
          "resolutionStrategy": {
            "type": "AUTOMERGE"
          },
          "entityName": "Message"
        },
        {
          "resolutionStrategy": {
            "type": "AUTOMERGE"
          },
          "entityName": "Dummy"
        }
      ]
    }

[HuiSF]

Hello @justkj7 sorry for the delayed response. I was trying to repro this issue you were experience.

Could you let me know:

• Is this still happening for you?
• when you say "when DataStore.save() is invoked, it seems local db is updated but db in remote server is not updated correspondingly", was that happening for all models listed in your schema? Or any particular one?
• In your output of amplify status, I noticed that you had local changes on the schema, did you try to amplify push to deploy the changes into cloud and to save again?

[HuiSF]

Hi @justkj7 I see the issue now.

Looking at your schema for Room model

type Room @model @auth(rules: [{allow: public}]) {
  id: ID! @index(name: "roomIdOnCreatedAt", sortKeyFields: ["createdAt"], queryField: "roomIdOnCreatedAt")
  name: String!
  Messages: [Message] @hasMany(indexName: "byRoom", fields: ["id"])
  createdAt: AWSDateTime
}

You are creating a Secondary Index on the model id field (this field is the partition key in DynamoDB), where you also specified createdAt as the sort key of this index.

When you invoke the save API:

Room newRoom = Room(
  name: _tfNameController.text,
);
await Amplify.DataStore.save(newRoom);

You haven't provided a value for createdAt field. In this case, when DataStore tries to sync this newly saved data to cloud it uses the following mutation, within which createdAt is assigned null.

{
	"variables": {
		"input": {
			"name": "a room",
			"id": "0417e26f-c95c-4f38-8c4d-9e9b00e0ae5b",
			"createdAt": null
		}
	},
	"query": "mutation CreateRoom($input: CreateRoomInput!) {\n  createRoom(input: $input) {\n    id\n    createdAt\n    name\n    updatedAt\n    __typename\n    _version\n    _deleted\n    _lastChangedAt\n  }\n}"
}

As createdAt is used as the sort key in the secondary index, it's required to be empty, or to have a valid value. But this mutation explicitly lists createdAt as null, which trigger validation error:

{
	"data": {
		"createRoom": null
	},
	"errors": [{
		"path": ["createRoom"],
		"data": null,
		"errorType": "DynamoDB:DynamoDbException",
		"errorInfo": null,
		"locations": [{
			"line": 2,
			"column": 3,
			"sourceName": null
		}],
		"message": "One or more parameter values were invalid: Type mismatch for Index Key createdAt Expected: S Actual: NULL IndexName: roomIdOnCreatedAt (Service: DynamoDb, Status Code: 400, Request ID: 1FPMGDEJ1D64H5VD267OABTU6RVV4KQNSO5AEMVJF66Q9ASUAAJG)"
	}]
}

So the data failed to sync to cloud. As your createdAt field is optional, I think this validation should not complain errors. I will confirm this with Amplify Data team.

In the meantime, please try to provide a valid value for createdAt, which ensures your records can be synced to cloud.

[justkj7]

Hi @HuiSF

Thanks a lot for answering my queries. The reason not to specify createAt when saving is to make it assigned value by server.
Is there any way to use createdAt which value is assigned by server as sorted key?

[HuiSF]

Hi @justkj7 sorry for the delayed response. This issue is very similar to aws-amplify/amplify-flutter#306 which probably requires a fix in the transformer. I've reached out to amplify-category-api maintainers for taking a look.

[Abdelazeem777]

I am facing the same issue here!

[dpilch]

Duplicate of aws-amplify/amplify-flutter#5050

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