如何在 apollo graphql 服务器中创建嵌套解析器

问题描述

给定以下 apollo 服务器 graphql 架构我想将这些分解成单独的模块，所以我不希望在根查询模式下的作者查询..并希望将其分开.所以我在将它添加到根查询之前添加了另一个名为 authorQueries 的层

Given the following apollo server graphql schemaI wanted to break these down into separate modules so I don't want the author query under the root Query schema.. and want it separated. So i added another layer called authorQueries before adding it to the Root Query

type Author {
    id: Int,
    firstName: String,
    lastName: String
}  
type authorQueries {
    author(firstName: String, lastName: String): Author
}

type Query {
    authorQueries: authorQueries
}

schema {
    query: Query
}

我尝试了以下..您可以看到在指定作者函数之前将 authorQueries 添加为另一层.

I tried the following.. you can see that authorQueries was added as another layer before the author function is specified.

Query: {
    authorQueries :{
        author (root, args) {
            return {}
       }
    }
}

在 Graphiql 中查询时，我还添加了额外的层..

When querying in Graphiql, I also added that extra layer..

{
    authorQueries {
        author(firstName: "Stephen") {
            id
        }
    }
}

我收到以下错误.

"message": "Resolve function for \"Query.authorQueries\" returned undefined",

推荐答案

要创建嵌套"解析器，只需在父字段的返回类型上定义解析器.在这种情况下，您的 authorQueries 字段返回类型 authorQueries，因此您可以将解析器放在那里:

To create a "nested" resolver, simply define the resolver on the return type of the parent field. In this case, your authorQueries field returns the type authorQueries, so you can put your resolver there:

{
  Query: { authorQueries: () => ({}) },
  authorQueries: {
    author(root, args) {
      return "Hello, world!";
    }
  }
}

所以从技术意义上讲，没有嵌套解析器这样的东西——每个对象类型都有一个扁平的字段列表，这些字段有返回类型.GraphQL 查询的嵌套是结果嵌套的原因.

So in the technical sense, there is no such thing as a nested resolver - every object type has a flat list of fields, and those fields have return types. The nesting of the GraphQL query is what makes the result nested.

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