GraphQL从axios返回空数据 [英] GraphQL returning null data from axios

问题描述

我正在用Node.js和Express编写GraphQL服务器.我有一个JSON数据文件，因此我正在使用Axios从该JSON文件查询数据并将其传递给GraphQL查询，

I am writing a GraphQL server in Node.js and Express. I have a JSON file of data and so I am using Axios to query data from that JSON file and pass it to GraphQL query,

const RootQuery = new GraphQLObjectType({
name:'RootQueryType',
fields: {
    holiday: {
        type: Holiday,
        args:{
            date:{type:GraphQLString},
        },
        resolve(parentValue, args) {
            return axios.get('http://localhost:3000/holidays?date='+ args.date).then(res => res.data);
        }
    },

在console.log(res.data)上，我正在获取数据，但是，在从GraphiQL中按日期查询时，我正在获取

On console.log(res.data), I am getting the data, however, on querying by date from GraphiQL, I am getting

{ "data": { "holiday": { "holiday": null } } }

{ "data": { "holiday": { "holiday": null } } }

推荐答案

有时我遇到了完全相同的问题.我意识到从REST API/JSON文件中获取数据需要一些时间，而GraphQL并没有等待接收它.因此，我决定使用Async和Await，这样GraphQL就等待接收数据.在您的情况下，代码如下所示:

I struggled with the exact same issue sometime back. I realized that the data from the REST API / JSON file take some time to be fetched and GraphQL doesn't wait to receive it. So I decided to use Async and Await, and that way, GraphQL waited for the data to be received. In your case, the code would look like:

const RootQuery = new GraphQLObjectType({
name:'RootQueryType',
fields: {
    holiday: {
        type: Holiday,
        args:{
            date:{type:GraphQLString},
        },
        Async resolve(parentValue, args) {
            const results= await axios.get('http://localhost:3000/holidays?date='+ args.date)
           .then(res => res.data);
           return results;
        }
    },

这篇关于GraphQL从axios返回空数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！