如何使用 Apollo 为 API 返回的对象列表制作 GraphQL 解析器？

Question

我是 GraphQL 的新手，想运行我的第一个应用程序。我看过几个例子，但他们使用了几个库，我只想要简单的例子。我看过https://www.youtube.com/watch?v=hLcAlln-D_s

我的Index.js代码

const { ApolloServer, gql } = require("apollo-server");
const fetch = require("node-fetch");    
const typeDefs = `
  type Query {   
    getApplicant: [Applicant]
  }
  type Applicant {
    FiscalYear:String
    JobNumber: String
    JobDescription: String
    AppsReceived: Int
    Female: Int
    Male: Int
    UnknownGender: Int
    Black: Int
    Hispanic: Int
    Asian: Int
    Caucasian: Int 
    AmericanIndian:Int
    Filipino: Int
    UnknownEthnicity: Int    
  } `;
const url = `http://localhost:52993/api/values`;    
const resolvers = {
    Query: {
        getApplicant: async () => {
            const response = await fetch(url).then(res => res.json());
            console.log(response);
            return response;                
        }
    }
};
const server = new ApolloServer({ typeDefs, resolvers });
server.listen().then(({ url }) => {
    console.log(`  Server ready at ${url}`);
});

从 API

返回的数据

[{   "FiscalYear": "2013-2014",
    "JobNumber": "9206 OP 2014/04/18",
    "JobDescription": "311 DIRECTOR 9206",
    "AppsReceived": 54,
    "Female": 20,
    "Male": 31,
    "UnknownGender": 3,
    "Black": 25,
    "Hispanic": 18,
    "Asian": 1,
    "Caucasian": 6,
    "AmericanIndian": 0,
    "Filipino": 0,
    "UnknownEthnicity": 4
  },
  {
    "FiscalYear": "2013-2014",
    "JobNumber": "1223 P 2013/08/09",
    "JobDescription": "ACCOUNTING CLERK 1223",
    "AppsReceived": 648,
    "Female": 488,
    "Male": 152,
    "UnknownGender": 8,
    "Black": 151,
    "Hispanic": 204,
    "Asian": 123,
    "Caucasian": 62,
    "AmericanIndian": 3,
    "Filipino": 79,
    "UnknownEthnicity": 26
  }]

当我查询数据时它总是显示null.What我不见了？

Answer 1

我已经尝试了另一个 API 并且它使用相同的代码运行良好，只是更改了架构相关的东西。尽管我的 .net 核心 Web API 返回了与上述相同的数据，但为了使我的解析器正常工作，我做了两件事

我从 API Get 方法返回了以下内容：

var myJObject = Newtonsoft.Json.JsonConvert.DeserializeObject<List<Applicant>>(json);
return Ok(myJObject);

在架构中，我将 "Applicant" 属性修改为驼峰式大小写。正如我所见，我的 API 正在返回未映射到我的 "Applicant" 架构

我为此花了几个小时，所以我发现它值得分享。

如何使用 Apollo 为 API 返回的对象列表制作 GraphQL 解析器？

How to make GraphQL resolver for list of objects returned by API using Apollo?

graphql

graphql-js

apollo-server