GraphQL 中的节点和边是如何连接的？

Question

我正在使用https://arrows.app/创建一个基本网络：

它创建的结果 GraphQL 是：

type Person {
  Name: Dante Alighieri
  wroteBook: Book @relationship(type: "WROTE", direction: OUT)
}

type Book {
  Title: The Inferno
  personWrote: Person @relationship(type: "WROTE", direction: IN)
  personReviewed: Person @relationship(type: "REVIEWED", direction: IN)
  personRead: Person @relationship(type: "READ", direction: IN)
}

type Person {
  Name: Harold Bloom
  reviewedBook: Book @relationship(type: "REVIEWED", direction: OUT)
  reviewedBook: Book @relationship(type: "REVIEWED", direction: OUT)
}
...

我们如何在 GraphQL 中知道这两个关系是“链接”的？

type Person {
  Name: Dante Alighieri
  wroteBook: Book @relationship(type: "WROTE", direction: OUT)
}
type Book {
  Title: The Inferno
  personWrote: Person @relationship(type: "WROTE", direction: IN)
}

GraphQL 中的顺序排序是否暗示存在关系，因为在“Person[@Name=Dante Alighieri].wroteBook”条目中没有 ID 或提及“地狱”。 例如，我们怎么知道它没有引用后面的条目，例如：

type Book {
  Title: The Tempest
  personWrote: Person @relationship(type: "WROTE", direction: IN)
}

Answer 1

您可以做的一件事是通过以下方式定义您的架构：

type Book{
 id: ID!
 title: String!
 personWrote: Person!
}

GraphQL 知道如何 map 这两个方法是通过在解析器中为 Book 类型创建解析器：

   export default {
    Query: {
        ...
    },
    Mutation: {
        ...
    },
    Book: {
        personWrote: async (parent, __, context) => {
            const bookId = parent.id

            //fetch the author who wrote the book from your database
            const bookAuthor = Authors.findBookById(id)

            return bookAuthor
        }
    }
}

这样，GraphQL 现在期待一个作者类型，并且可以进一步访问其所有字段。