javascript - GraphQL: TypeError: Cannot read property of undefined - Stack Overflow

admin管理员组

文章数量:1323335

I have an Apollo GraphQL projects where I have created my own Query and Mutations. I have done using mock data and Query and Mutation works fine. But when I am trying to do with Sequelize ORM, I am getting the error

"TypeError: Cannot read property 'getListings' of undefined",
            "    at listings (/home/ayman/Desktop/apollo-graphql/graphql-app/functions/graphql.js:50:19)",
            "    at field.resolve (/home/ayman/Desktop/apollo-graphql/graphql-app/node_modules/graphql-extensions/dist/index.js:134:26)"

Query and Mutations in graphql.js:

const { ApolloServer, gql} = require("apollo-server-lambda");
const { Listing, User } = require("../db");
const jwt = require("jsonwebtoken");

const typeDefs = gql`
  type Query {
    listings: [Listing!]!
  }
  type Mutation {
    createListing(input: CreateListingInput!): Listing!
  }
  input CreateListingInput {
    title: String!
    description: String
    url: String!
    notes: String
  }
  type Contact {
    id: ID!
    name: String!
    pany: Company
    email: String
    notes: String
  }
  type Company {
    id: ID!
    name: String!
    logo: String
    listings: [Listing!]!
    url: String
  }
  type Listing {
    id: ID!
    title: String!
    description: String
    url: String!
    notes: String
    pany: Company
    contacts: [Contact!]!
  }
`;

const resolvers = {
  Query: {
    listings(_, __, { user }) {
      return user.getListings();
    },
  },
  Mutation: {
    createListing(_, { input }, { user }) {
      return Listing.create({ ...input, userId: user.id });
    },
  },
};

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

exports.handler = server.createHandler();

I have Sequilize along with Postgres database:

db.js

const Sequelize = require("sequelize");

const sequelize = new Sequelize(process.env.DB_CONNECTION_STRING, {
  dialect: "pg",
  dialectModule: require('pg'),
  dialectOptions: {
    ssl: true,
  },
});

class User extends Sequelize.Model {}
User.init(
  {
    email: Sequelize.STRING,
    password: Sequelize.STRING,
  },
  {
    sequelize,
    modelName: "user",
  }
);

class Listing extends Sequelize.Model {}
Listing.init(
  {
    title: Sequelize.STRING,
    description: Sequelize.TEXT,
    url: Sequelize.STRING,
    notes: Sequelize.TEXT,
  },
  {
    sequelize,
    modelName: "listing",
  }
);

Listing.belongsTo(User);
User.hasMany(Listing);

exports.sequelize = sequelize;
exports.User = User;
exports.Listing = Listing;

Github Link

1. Run using netlify dev

2. Go to URL: http://localhost:8888/lify/functions/graphql

3. Sample GraphQL query

{
 listings {
     id
     title
     description
     url
     pany {
        name
        url
     }
    }
}

I have an Apollo GraphQL projects where I have created my own Query and Mutations. I have done using mock data and Query and Mutation works fine. But when I am trying to do with Sequelize ORM, I am getting the error

"TypeError: Cannot read property 'getListings' of undefined",
            "    at listings (/home/ayman/Desktop/apollo-graphql/graphql-app/functions/graphql.js:50:19)",
            "    at field.resolve (/home/ayman/Desktop/apollo-graphql/graphql-app/node_modules/graphql-extensions/dist/index.js:134:26)"

Query and Mutations in graphql.js:

const { ApolloServer, gql} = require("apollo-server-lambda");
const { Listing, User } = require("../db");
const jwt = require("jsonwebtoken");

const typeDefs = gql`
  type Query {
    listings: [Listing!]!
  }
  type Mutation {
    createListing(input: CreateListingInput!): Listing!
  }
  input CreateListingInput {
    title: String!
    description: String
    url: String!
    notes: String
  }
  type Contact {
    id: ID!
    name: String!
    pany: Company
    email: String
    notes: String
  }
  type Company {
    id: ID!
    name: String!
    logo: String
    listings: [Listing!]!
    url: String
  }
  type Listing {
    id: ID!
    title: String!
    description: String
    url: String!
    notes: String
    pany: Company
    contacts: [Contact!]!
  }
`;

const resolvers = {
  Query: {
    listings(_, __, { user }) {
      return user.getListings();
    },
  },
  Mutation: {
    createListing(_, { input }, { user }) {
      return Listing.create({ ...input, userId: user.id });
    },
  },
};

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

exports.handler = server.createHandler();

I have Sequilize along with Postgres database:

db.js

const Sequelize = require("sequelize");

const sequelize = new Sequelize(process.env.DB_CONNECTION_STRING, {
  dialect: "pg",
  dialectModule: require('pg'),
  dialectOptions: {
    ssl: true,
  },
});

class User extends Sequelize.Model {}
User.init(
  {
    email: Sequelize.STRING,
    password: Sequelize.STRING,
  },
  {
    sequelize,
    modelName: "user",
  }
);

class Listing extends Sequelize.Model {}
Listing.init(
  {
    title: Sequelize.STRING,
    description: Sequelize.TEXT,
    url: Sequelize.STRING,
    notes: Sequelize.TEXT,
  },
  {
    sequelize,
    modelName: "listing",
  }
);

Listing.belongsTo(User);
User.hasMany(Listing);

exports.sequelize = sequelize;
exports.User = User;
exports.Listing = Listing;

Github Link

1. Run using netlify dev

2. Go to URL: http://localhost:8888/lify/functions/graphql

3. Sample GraphQL query

{
 listings {
     id
     title
     description
     url
     pany {
        name
        url
     }
    }
}

• javascript
• graphql
• sequelize.js
• apollo
• react-apollo

Share Improve this question Follow asked Aug 16, 2020 at 10:23 Ayman ArifAyman Arif 1,69933 gold badges1919 silver badges4343 bronze badges 4

• Where are you creating your context object? – goto Commented Aug 16, 2020 at 12:09
• I am using user from db.js as part of Apollo's resolver. – Ayman Arif Commented Aug 16, 2020 at 14:30
• Looks like you're trying to use the third argument of the resolver, which is context - apollographql./docs/apollo-server/data/resolvers/…, but you're never adding a context initialization function to the ApolloServer constructor. – goto Commented Aug 16, 2020 at 16:14
• did you manage to find a solution? – M.Ionut Commented Mar 3, 2022 at 20:13

Add a ment  | 

2 Answers 2

Sorted by: Reset to default 0

return user.getListings();

you probably mean User, because user is undefined

I see, you are trying to access user object from context. Please check the context definition. It should return an object containing user object explicitly.

本文标签： javascriptGraphQL TypeError Cannot read property of undefinedStack Overflow