graphql中未定义类型的输出错误答案

【问题标题】：undefined type of output error in graphqlgraphql中未定义类型的输出错误
【发布时间】：2019-04-25 09:53:34
【问题描述】：

我用 mongodb 在 graphql 服务器和 nodejs 中编写了一个简单的代码。我有一个包含 2 个集合的数据库。明星和电影。当我运行此查询以显示所有电影时，我的 GraphQL NodeJS 服务器出现以下错误： “MovieType.year 的类型必须是 Output Type 但得到：未定义。”

这是我的架构：

    const {
    GraphQLSchema,
    GraphQLObjectType,
    GraphQLString,
    GraphQLInt,
    GraphQLNonNull,
    GraphQLList
} = require("graphql");
const {Movie, User} = require('/home/fateme/imdb_final/db')


const starType = new GraphQLObjectType({
    name: "UserType",
    fields: {
      name: {
        type: GraphQLString,
        async resolve(objId) {
            const starFind = await User.findOne({ _id: objId._id})
            return starFind.name
        }
      },
      imdbId: {
        type: GraphQLString,
        async resolve(objId) {
            const starFind = await User.findOne({ _id: objId._id}) 
            return starFind.imdbId
        }
      }
    }
  });

const movieType = new GraphQLObjectType({
    name: "MovieType",
    fields: {
      title: {
        type: GraphQLString,
        async resolve(objId) {
            const movieFind = await Movie.findOne({ _id: objId._id})
            return movieFind.title
        }
      },
      year: {
        type: GraphQLInt,
        async resolve(objId) {
            const movieFind = await Movie.findOne({ _id: objId._id})
            return movieFind.year
        }
      },
      rate: {
        type: GraphQLInt,
        async resolve(objId) {
            const movieFind = await Movie.findOne({ _id: objId._id})
            return movieFind.rating
        }
      },
      year: {
        rate: GraphQLInt,
        async resolve(objId) {
            const movieFind = await Movie.findOne({ _id: objId._id})
            return movieFind.year
        }
      },
      director: {
        type: GraphQLString,
        async resolve(objId) {
            const movieFind = await Movie.findOne({ _id: objId._id})
            return movieFind.director
        }
      },
    }
  });


  const queryType = new GraphQLObjectType({
    name: 'Query',
    fields: () => ({

        users: {
            type: GraphQLList(starType),
            async resolve() {

              const allStar = await User.find({})
              return  allStar
            }
          },

      movies: {
        type: GraphQLList(movieType),
        async resolve() {

            const allMovie = await Movie.find({})
            console.log(allMovie)
            return  allMovie
          } 
        },
    })
  });

  const schema = new GraphQLSchema({
    query: queryType
  });

  module.exports = schema;

【问题讨论】：

标签： node.js mongoose graphql

【解决方案1】：

如错误所示，您尚未为 year 字段定义类型。相反，您不小心添加了 rate 字段：

year: {
    rate: GraphQLInt, // <-- here
    async resolve(objId) {
        const movieFind = await Movie.findOne({ _id: objId._id})
        return movieFind.year
    }
},

只需将 rate 更改为 type 即可：)

【讨论】：