Write a Mutation where one field has #belongsTo - GraphQL - amazon-web-services

Question

My goal is to write an app where users can add a list of Items (lets say 20-30) to every Entry... There would be one entry per day and the number of items would be different each time.
I have two GraphQL types which look like this:
type Entry #model #auth(rules: [{allow: public}]) {
id: ID!
date: String!
entries: [Item] #hasMany
}
type Item #model #auth(rules: [{allow: public}]) {
id: ID!
name: String!
received: Boolean!
quantity: String!
hazardRating: Int!
entry: Entry #belongsTo
comments: [Comment] #hasMany
}
type Comment #auth(rules: [{allow: public}]) #model {
id: ID!
item: Item #belongsTo
content: String!
}
I want to write a mutation which adds an Item to an existing Entry:
I have tried this:
mutation createItem{
createItem( input:{name: "Sodium Hydroxide", received: true, quantity: "1L", hazardRating: 3, entry: {id = "7a59cfca-db53-4f15-8ae6-c37e025b2a44", date = "21 October 2022" }) {
id
name
received
quantity
hazardRating
entry {
id
date
}
}
}
but I get the error message "entry" does not exist on type Item...
How would I write a mutation that would add an Item to an existing Entry?
Is it even possible to do so or is it only possible to add all the Items per Entry at the same time?

Answer 1

I was missing references in Item.
In order that Item is recognised as part of Entry - you have to add entryID: ID! #index(name: "byEntry", sortKeyFields: ["name"]) into Item and also an indexName parameter into entry: (indexName: "byEntry", fields: ["id"])
Unlike GraphQL v1 - v2 fails to do this automatically when you start a schema from scratch so you have to make sure each type references each other.
The whole scheme looks like this:
type Entry #model #auth(rules: [{allow: public}]) {
id: ID!
date: String!
items: [Item] #hasMany(indexName: "byEntry", fields: ["id"])
}
type Item #model #auth(rules: [{allow: public}]) {
id: ID!
entryID: ID! #index(name: "byEntry", sortKeyFields: ["name"])
name: String!
amount: String!
hazardRating: Int!
comments: [Comment] #hasMany(indexName: "byItem", fields: ["id"])
}
type Comment #model #auth(rules: [{allow: public}]) {
id: ID!
itemID: ID! #index(name: "byItem" sortKeyFields: ["content"])
content: String!
}