Many To Many Relation not working

[HusseinReda97pro]

Description

when I declare Many To Many Relation and query models many-to-many list come with null value

Categories

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

Steps to Reproduce

GraphQL scheam

type Category @model @auth(rules: [{ allow: public }]) {
id: ID!
name: String!
order: Int
people: [Person] @manytomany(relationName: "PersonCategories")

}

type Taxonomy @model @auth(rules: [{ allow: public }]) {
id: ID!
name: String!
emoji: String
people: [Person] @manytomany(relationName: "PersonTaxonomies")
}

type Person @model @auth(rules: [{ allow: public }]) {
id: ID!
first_name: String!
last_name: String!
bio: String
city: String
country: String
image: String
job_title: String
organization: String
taxonomies: [Taxonomy] @manytomany(relationName: "PersonTaxonomies")
categories: [Category] @manytomany(relationName: "PersonCategories")
is_featured: Boolean
is_discoverable: Boolean
}

query person

final persons = await Amplify.DataStore.query(Person.classType);
print(persons.first.taxonomies);
taxonomies come with null value

and any many-to-many relation
also the data saved correct in data base and the GraphQL Request on API retrieve data

like this

Future customRequest2() async {
const document = '''
query GetPeople {
listPeople {
items {
id
first_name
last_name
bio
city
country
image
job_title
organization
is_featured
is_discoverable
industry {
id
name
}
taxonomies {
items {
id
taxonomy {
id
name
emoji
}
}
}
categories {
items {
id
category {
id
name
}
}
}
goals {
items {
id
goal {
id
name
}
}
}
}
}
}
''';

final request = GraphQLRequest<String>(
  document: document,
  decodePath: 'listPeople',
);

try {

  final response = await Amplify.API.query(request: request).response;

  if (response.errors.isNotEmpty) {
    print('Response Error: ${response.errors}');
  } else {
    print("data: ${response.data}");
    final List<dynamic> items = jsonDecode(response.data!)['listPeople']['items'];
    final List<Person> people = items.map((item) => Person.fromJson(item)).toList();

    print('Response data: ${people.length}');

    setState(() {
      persons = people;
    });
  }
} catch (e, sk) {
  print('An error occurred: $e');
  print(sk);
}

}

I don't know why DataStore does not retrieve taxonomies and categories with every person

Screenshots

No response

Platforms

• iOS
• Android
• Web
• macOS
• Windows
• Linux

Flutter Version

3.22.3

Amplify Flutter Version

^2.5.0

Deployment Method

Amplify CLI (Gen 1)

Schema

type Category @model @auth(rules: [{ allow: public }]) {
    id: ID!
    name: String!
    order: Int
    people: [Person] @manyToMany(relationName: "PersonCategories")


}

type Taxonomy @model @auth(rules: [{ allow: public }]) {
    id: ID!
    name: String!
    emoji: String
    people: [Person] @manyToMany(relationName: "PersonTaxonomies")
}


type Person @model @auth(rules: [{ allow: public }]) {
    id: ID!
    first_name: String!
    last_name: String!
    bio: String
    city: String
    country: String
    image: String
    job_title: String
    organization: String
    taxonomies: [Taxonomy] @manyToMany(relationName: "PersonTaxonomies")
    categories: [Category] @manyToMany(relationName: "PersonCategories")
    is_featured: Boolean
    is_discoverable: Boolean
}

[ekjotmultani]

Hi @HusseinReda97pro, I'm sorry you are facing this issue. I will attempt to reproduce and get back to you

[tyllark]

Hello @HusseinReda97pro, we were able to reproduce the issue you described and marked it as a bug. We will update here once we have a fix.

As a workaround we recommend creating your own join table to manage this many to many relationship. Gen 2 does not support the manyToMany directive, but it has a guide for how to represent a many to many relationship with the hasMany and belongsTo directives.

[HusseinReda97pro]

we use Gen 1 as Gen 2 does not support Datastore, and also for one to many relations I faced the same issue as the list marked with hasMany, not received when I query data so it another issue

[ekjotmultani]

Hi @HusseinReda97pro, thanks for the response, we will investigate why hasMany is containing null values as well.

[homer-blink]

Is there any update on this? It seems that the issue is still not resolved, as I am encountering the same problem with a many-to-many relationship and hasMany as well.

[tyllark]

@homer-blink, we do not have an update yet, but we will post here when we do.