如何在我的 GraphQL 中为对象中的对象列表定义类型
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【中文标题】如何在我的 GraphQL 中为对象中的对象列表定义类型【英文标题】：How to define a type in my GraphQL for list of Objects in an object 【发布时间】：2020-09-29 10:32:28 【问题描述】：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;
【问题讨论】：
【参考方案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;
【讨论】：
是的，我会试试这个，这应该可以，如果我的客户端依赖于基于字典的数据，我应该只在客户端实现更改吗？基本上我正在做的是基于像“topic-1”这样的dict属性映射数据，所以我需要在我的数据中使用它。 是的，我完全理解。如果在客户端，您正在寻找基于 id 的对象，那么您必须在那里进行转换。但是，为此您可以使用单独的 api 根据 id 获取一个对象。 好的，但问题仍然不清楚，即使对于我字典中的一个对象，比如说 topic-1，我该如何发送它，就像我在 GraphQL 知识方面非常初学者一样，请帮助我:( 我已经用另一个函数更新了我的答案，该函数基于 id 作为参数获取单个对象。希望这会有所帮助以上是关于如何在我的 GraphQL 中为对象中的对象列表定义类型的主要内容，如果未能解决你的问题，请参考以下文章
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