Filter Expression can only contain non-primary key attributes - amazon-web-services

Question

I'm new to AWS Amplify, and have created a GraphQL API for a project that I'm working on in order to learn it & AppSync. Essentially I have a schema that looks like the following:
type User #model {
id: ID! #primaryKey
boards: [Board] #hasMany
createdAt: String!
updatedAt: String!
}
type Board #model {
id: ID! #primaryKey
createdBy: User!
title: String!
}
and I'm trying to run the following query in the AppSync console:
query MyQuery {
listUsers {
items {
boards {
items {
title
}
}
}
}
}
But for some reason I keep seeing this error:
Filter Expression can only contain non-primary key attributes: Primary key attribute: userBoardsId
I've specified the primary key in both models, and I'm aware that AppSync generates the 'userBoardsId' foreign key, but I'm not sure why it's causing an issue.

Answer 1

Have you tried like this? Since boards is array, you need to add items
query MyQuery {
listUsers {
items {
boards {
items {
title
}
}
}
}
}
EDIT:
type User #model {
id: ID! #primaryKey
boards: [Board] #hasMany (indexName: "byUser")
createdAt: String!
updatedAt: String!
}
type Board #model {
id: ID! #primaryKey
userID: ID! #index(name: "byUser")
createdBy: User
title: String!
}