GraphQL引发语法错误

我正在开发GraphQL Node教程，并完成第7步。

https://www.howtographql.com/graphql-js/7-subscriptions/

我在datamodel.prisma文件中的此代码中收到许多语法错误：

directive @id on FIELD_DEFINITION
directive @unique on FIELD_DEFINITION
directive @createdAt on FIELD_DEFINITION
scalar DateTime

type Link {
    id: ID! @id
    createdAt: DateTime! @createdAt
    description: String!
    url: String!
    postedBy: User
    votes: [Vote!]!
}

type User {
    id: ID! @id
    name: String!
    email: String! @unique
    password: String!
    links: [Link!]!
    votes: [Vote!]!
}

type Vote {
    id: ID! @id
    link: Link!
    user: User!
}

但是我仍然变得'User' type [@6:1] tried to redefine existing 'User' type [@15:5]和'Link' type [@24:1] tried to redefine existing 'Link' type [@6:5]。

我也不确定是否要声明directives或scalars正确，因为官方教程中缺少此内容。

任何人都可以就如何解决这些问题提供任何建议吗？

Schema.graphql：

type Query {
    info: String!
    feed(filter: String, skip: Int, first: Int, orderBy: LinkOrderByInput): Feed!
}

type Feed {
    links: [Link!]!
    count: Int!
}

type AuthPayload {
    token: String
    user: User
}

type User {
    id: ID!
    name: String!
    email: String!
    links: [Link!]!
}

type Vote {
    id: ID!
    link: Link!
    user: User!
}

type Link {
    id: ID!
    description: String!
    url: String!
    postedBy: User
    votes: [Vote!]!
}

type Subscription {
    newLink: Link
    newVote: Vote
}

type Mutation {
    post(url: String!, description: String!): Link!
    signup(email: String!, password: String!, name: String!): AuthPayload
    login(email: String!, password: String!): AuthPayload
    vote(linkId: ID!): Vote
}

enum LinkOrderByInput {
    description_ASC
    description_DESC
    url_ASC
    url_DESC
    createdAt_ASC
    createdAt_DESC
}