Question

我正在通过他们的官方website学习GraphQL。

我的graphql对此代码的目的是作为现有REST API的包装器。要做到这一点，我已经有了这个回复的休息api：

<img src="http://localhost/wp/wp-content/uploads/2017/05/IMG_0061-300x225.jpg" alt="garden image" width="300" height="225" class="alignnone size-medium wp-image-386916" />

以下代码是我的graphql架构

GET: /people/:id
RESPONSE: 
{
  "person": [
    {
      "id": "1",
      "userName": "mark1",
      "firstName": "Mark",
      "lastName": "Zuckerberg",
      "email": "mark@facebook.com",
      "friends": [
        "/people/2",
        "/people/3"
      ]
    }
  ]
}

当我使用import { GraphQLList, GraphQLObjectType, GraphQLString, GraphQLSchema } from "graphql"; import fetch from "node-fetch"; const BASE_URL = "http://localhost:5000"; function getPersonByURL(relativeUrl) { return fetch(`${BASE_URL}${relativeUrl}`) .then(res => res.json()) .then(json => json.person); } const PersonType = new GraphQLObjectType({ name: "Person", type: "Somebody", fields: () => ({ firstName: { type: GraphQLString, resolve: person => person.firstName }, lastName: { type: GraphQLString, resolve: person => person.lastName }, email: { type: GraphQLString }, id: { type: GraphQLString }, userName: { type: GraphQLString }, friends: { type: new GraphQLList(PersonType), resolve: (person) => person.friends.map(getPersonByURL) } }) }); const QueryType = new GraphQLObjectType({ name: "Query", description: "the root of all queries", fields: () => ({ person: { type: PersonType, args: { id: { type: GraphQLString } }, resolve: (root, args) => getPersonByURL(`/people/${args.id}`) } }) }); export default new GraphQLSchema({ query: QueryType });执行请求时，它在每个字段上返回null。我相信我在如何表示我的json响应或如何从rest api访问我的json响应时犯了错误。

这些是来自Graphiql

的请求和结果

graphiql

你能帮忙解决一下吗？

Answer 1

要找到问题，我已将你的json放在gist上并修改你的代码如下：

// ...
firstName: {
  type: GraphQLString,
  resolve: person => JSON.stringify(person)
},
// ...

运行以下查询后：

{
  person(id: "1") {
    firstName
  }
}

结果如下：

{
"data": {
    "person": {
      "firstName": "[{\"id\":\"1\",\"userName\":\"mark1\",\"firstName\":\"Mark\",\"lastName\":\"Zuckerberg\",\"email\":\"mark@facebook.com\",\"friends\":[\"/people/2\",\"/people/3\"]}]"
    }
  }
}

您可以注意到person 数组，所以很明显它没有firstName和其他属性。您必须在每个字段解析程序或根类型解析程序中解包数组：

resolve: (root, args) => getPersonByURL(`/people${args.id}.json`)
  .then(persons => persons[0])

这是带有工作代码的GraphQL Launchpad：https://launchpad.graphql.com/j1v0kprrp

Node GraphQL解析API中的空数据

1 个答案: