如何在我的 GraphQL 中为对象中的对象列表定义类型

Question

我对 graphql 还是很陌生，不知道如何在对象中为我的对象列表定义类型，我可以在互联网上找到有关数组中的对象列表的教程，而不是在对象中。我正在附加我的数据，在此我尝试在 Schema 中编写一个对象类型，但它似乎不起作用，请任何帮助将不胜感激，在此先感谢！

    var createError = require('http-errors');
var express = require('express');
var path = require('path');
var bodyParser = require('body-parser')
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var graphqlHTTP = require('express-graphql');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
const {buildSchema} = require('graphql');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(bodyParser.json());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', indexRouter);
app.use('/users', usersRouter);


app.use('/graphql', graphqlHTTP({
  schema: buildSchema(`

    type topicInfo{
      id: String!
      topicName: String!
      topicDescription: String!
      topicTags: [String!]!
    }

    type RootQuery {
      topicCards: topicInfo
    }
    type RootMutation {
      createEvent(name:String) : String
    }
    schema {
      query: RootQuery
      mutation: RootMutation
    }
  `),
  rootValue: {
    topicCards: () =>{
      return (
        {
          "topic-1": {
            id: "topic-1",
            topicName: "Adding a feature: GSoC 1",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-2": {
            id: "topic-2",
            topicName: "Adding a feature: GSoC 2",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-3": {
            id: "topic-3",
            topicName: "Adding a feature: GSoC 3",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-4": {
            id: "topic-4",
            topicName: "Adding a feature: GSoC 4",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-5": {
            id: "topic-5",
            topicName: "Adding a feature: GSoC 5",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-6": {
            id: "topic-6",
            topicName: "Adding a feature: GSoC 6",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-7": {
            id: "topic-7",
            topicName: "Adding a feature: GSoC 7",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-8": {
            id: "topic-8",
            topicName: "Adding a feature: GSoC 8",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-9": {
            id: "topic-9",
            topicName: "Adding a feature: GSoC 9",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          "topic-10": {
            id: "topic-10",
            topicName: "Adding a feature: GSoC 10",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
        }
      )
    }
  },
  graphiql:true
}));

module.exports = app;

Answer 1

我稍微更改了您的代码，这应该可以工作。变化是，1：topicCards 函数需要响应一个数组而不是一个字典。 2. 在解析器中，您也需要这样做。

app.use('/graphql', graphqlHTTP({
  schema: buildSchema(`

    type topicInfo{
      id: String!
      topicName: String!
      topicDescription: String!
      topicTags: [String!]!
    }

    type RootQuery {
      topicCards: [topicInfo]
      topicCardById (id: String!): topicInfo
    }

    type RootMutation {
      createEvent(name:String) : String
    }
    schema {
      query: RootQuery
      mutation: RootMutation
    }
  `),
  rootValue: {
    topicCardById: (obj, args, context, info) => {
      return ({
         id: "topic-1",
         topicName: "Adding a feature: GSoC 1",
         topicDescription: "Some quick example text to build on the card title and make up the bulk of the card's content.",
         topicTags: ["ReactJs", "NodeJS"],
      });
    }
    topicCards: () =>{
      return (
        [
          {
            id: "topic-1",
            topicName: "Adding a feature: GSoC 1",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          {
            id: "topic-2",
            topicName: "Adding a feature: GSoC 2",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          },
          {
            id: "topic-3",
            topicName: "Adding a feature: GSoC 3",
            topicDescription:
              "Some quick example text to build on the card title and make up the bulk of the card's content.",
            topicTags: ["ReactJs", "NodeJS"],
          }
        ]
      )
    }
  },
  graphiql:true
}));

module.exports = app;