Help with mutation for a relationship-as-a-type

Drivers & Stacks GraphQL & GRANDstack
1

I am just getting into working with GRANDStack and have found building out a schema to be really intuitive and enjoyable to work with.
However, I am trying to follow the example from the docs for creating a relationship as a type, as I seed my Neo4j instance. This is the example code:

type Movie {
  title: String
  year: Int
  ratings: [Rated]
}

type User {
  userId: ID
  name: String
  rated: [Rated]
}

type Rated @relation(name: "RATED") {
  from: User
  to: Movie
  rating: Float
  timestamp: Int
}

The mutations I am using are
export default /* GraphQL */ `
mutation {

movie1: CreateMovie (
  title: "First Movie Title"
  year: 1998
) {
  title
  year
}
user1: CreateUser (
  userId: "user1"
  name: "Gumby"
) {
  userId
  name
}
userrating1: AddMovieRatings (
  from: {userId: "user1"}
  to: {id: "246"}
  rating: 4.0
  timestamp: 2020
) {
  rating
  timestamp
}

}
`;
I can add a movie and a user, but Apollo gives me a 400 error when running the seedDb script that indicates (in my limited experience) that something is wrong with the AddMovieRatings mutation. Since seedDb only breaks after I add that mutation to the code.
I have the following mutations, and I have tried using the AddUserRated mutation but get same error result. These are the auto generated mutations in the schema

type Mutation {
CreateMovie(title: String, year: Int): Movie
UpdateMovie(title: String!, year: Int): Movie
DeleteMovie(title: String!): Movie
AddMovieRatings(
from: _UserInput!
to: _MovieInput!
data: _RatedInput!
): _AddMovieRatingsPayload
RemoveMovieRatings(
from: _UserInput!
to: _MovieInput!
): _RemoveMovieRatingsPayload
CreateUser(userId: ID, name: String): User
UpdateUser(userId: ID!, name: String): User
DeleteUser(userId: ID!): User
AddUserRated(
from: _UserInput!
to: _MovieInput!
data: _RatedInput!
): _AddUserRatedPayload
RemoveUserRated(from: _UserInput!, to: _MovieInput!): _RemoveUserRatedPayload
}

I think I am missing something simple here? Thanks for any help

2

For clarification, I mean I am not calling the AddMovieRatings mutation correctly (not that there is something wrong with the mutation itself)
I have tried using the data prop like this too, with no luck:

userrating1: AddMovieRatings (
  from: {userId: "user1"}
  to: {id: "246"}
  data: {rating: 4.0, timestamp: 2020}
) {
  rating
  timestamp
}

I am not sure if I am even calling the correct mutation to create the relationship? (The movie id I am using is a valid one.)

3

Hi @jgedmondson, I am having a similar issue Auto-generated Mutation Does Not Create Relationship. I see you posted this question more than two months ago, have you found a solution to your problem?
Thanks.

4

Nope, never found a solution.

No one from Neo4j commented, which is extremely disappointing.

Oh, wait, a Neo4j sales guy contacted me due to asking a question on the board, but when I mentioned my problem I never heard another word.

Not sure why they don't respond to questions but it has certainly changed my perception of them.

5

Yeah, It looks like we still need to write resolvers to manage some CRUD mutations.

As novices, we are probability asking something obvious, hence no response. Let's try luck and ask @lyonwj. I will let you know if I get any solution.

6

I felt the same - I read their docs and thought I had to be missing something obvious when no one responded.

Please (please) let me know if you get some resolution to this.

7

Based on your schema the, auto-generated mutation for creating the RATED relationship should be

AddUserRated(
from: _UserInput!
to: _MovieInput!
data: _RatedInput!
): _AddUserRatedPayload

so instead, your mutation should be

mutation {
  movie1: CreateMovie(title: "First Movie Title", year: 1998) {
    title
    year
  }
  user1: CreateUser(userId: "user1", name: "Gumby") {
    userId
    name
  }
  userrating1: AddUserRated(from: {userId: "user1"}, to: {title: "First Movie Title"}, data: {rating: 4.0, timestamp: 2020}) {
    rating
    timestamp
  }
}

Since there is no ID! field on the Movie type, instead the title field is treated as the id or primary-key type field.

I just tried this with your schema and seemed to work fine:

{
  "data": {
    "movie1": {
      "title": "First Movie Title",
      "year": 1998
    },
    "user1": {
      "userId": "user1",
      "name": "Gumby"
    },
    "userrating1": {
      "rating": 4,
      "timestamp": 2020
    }
  }
}

You can try running your query in GraphQL Playground (just open the GraphQL URL in a web browser) which will give you better error messages, auto-complete, as well as a way to inspect the schema to see what operations / arguments are available.

1 Like