Question

我只是从graphql开始，在操场上调用基本查询时遇到了一些问题。

我有一个server.js

const mongoose = require('mongoose');
require('dotenv').config({ path: 'variables.env' })

const { ApolloServer } = require('apollo-server')

//Monogoose schemas
const Recipe = require('./models/Recipe');

const { typeDefs } = require('./schema');
const { resolvers } = require('./resolvers')

const server = new ApolloServer({
  typeDefs,
  resolvers
})

// Connect to DB
mongoose
  .connect(process.env.MONGO_URI, { autoIndex: false })
  .then(() => {
    console.log('DB connected')
  })
  .catch(err => console.error(err))

server.listen().then(({ url }) => {
  console.log(`server listening on ${url}`)
})

一个schema.js

const gql = require('graphql-tag');

exports.typeDefs = gql`

  type Recipe{
    _id: ID
    name: String!
    category: String!
    description: String!
    instructions: String!
    createdDate: String
    likes: Int
    username: String
  }

  type Query {
    getAllRecipes: [Recipe]
  }

`

resolvers.js

exports.resolvers = {

  Query: {
    getAllRecipes: async (root, args, { Recipe }) => {
      const allRecipes = await Recipe.find()
      return allRecipes
    }
  },

和猫鼬模式

const mongoose = require('mongoose');
const Schema = mongoose.Schema

const RecipeSchema = new Schema({
  name: {
    type: String,
    required: true
  },
  category: {
    type: String,
    required: true
  },
  description: {
    type: String,
    required: true
  },
  instructions: {
    type: String,
    required: true
  },
  createdDate: {
    type: Date,
    default: Date.now
  },
  likes: {
    type: Number,
    default: 0
  },
  username: {
    type: String
  }

})

module.exports = mongoose.model('Recipe', RecipeSchema)

服务器和数据库的连接正常工作，当我打开操场时，将显示架构。我数据库中有数据

当我运行查询时：

query{
  getAllRecipes{
    name
  }
}

我收到一个错误"Cannot read property 'find' of undefined",

谁能在这里看到我在做什么错

Answer 1

在您的resolvers.js文件上，您期望Recipe来自context参数，但是您没有将其添加到我从摘录中得知的任何地方。

在初始化ApolloServer实例期间，您可以传递一个context属性，该属性将注入到所有解析程序中：

...
const server = new ApolloServer({
  typeDefs,
  resolvers,
  context: {
    Recipe,
  },
});

context属性也可以是一个函数，该函数可以在最后返回一个对象，以防您需要进一步详细说明。

有关该选项以及您可以通过的其他选项的更多详细信息，请参见：https://www.apollographql.com/docs/apollo-server/api/apollo-server/。

Graphql-从连接的数据库调用graphqlplayground中的查询

1 个答案: