Apollo Server 4 and apollo-datasource-mongodb

Help
1

Hi, I’m trying to get a simple example running with V4 Server and mongo datasource.
Getting: “Context creation failed: MongoDataSource constructor must be given a collection or Mongoose model”

I’m a newbe, anyone get this going? Any help / guidance would be appreciated.
Thanks,
Roy

2

Hey @Royt, data sources changed a bit in v4 so you might be working with some older documentation (the apollo-datasource-mongodb has not been updated/published since v4 so it’s dated).

Our migration guide explains how to use data sources that were compatible with v3 in v4.

3

Thanks Trevor, 5 minutes after I posted, I got it running!
This seems to work, saves and queries a simple employee doc {first Name, LastName} using mongodb data source package. Can you review and let me know if I did anything egregious?

Thanks,
Roy

const { ApolloServer } = require(“@apollo/server”);
const { startStandaloneServer } = require(‘@apollo/server/standalone’);
const { MongoDataSource } = require(“apollo-datasource-mongodb”);
const mongoose = require(“mongoose”);

const typeDefs = #graphql type Employee { firstName: String lastName: String } type Query { employees: [Employee] } type Mutation { CreateEmployee(firstName: String!, lastName: String!): Employee } ;

const EmployeeModel = mongoose.model(“Employee”, {
firstName: String,
lastName: String,
});
const resolvers = {
Query: {
employees: (, __, contextValue) => {
return contextValue.dataSources.employees.getEmployees()
},
},
Mutation: {
CreateEmployee: (, args, contextValue) => {
return contextValue.dataSources.employees.createEmployee(args)
},
},
};

class Employees extends MongoDataSource {
constructor(options) {
super(options);
this.initialize({ cache: options.cache, context: options.token });
}
async getEmployees() {
return await this.model.find();
}
async createEmployee(args) {
return await this.model.create(args);
}
}

const server = new ApolloServer({
typeDefs,
resolvers,
});
const MONGODB_URL = “mongodb://127.0.0.1:27017/test”;
async function connectMongodb() {
await mongoose.connect(MONGODB_URL);
console.log(“Connected to database successfully :tada:”);
}
(async () => {
// Connect to DB
try {
await connectMongodb();
} catch (e) {
console.error(e);
throw new Error(Unable to connect to database);
}

const { url } = await startStandaloneServer(server, {
listen: { port: 4000 },
context: async ({req}) => {
const { cache } =server;
const token = req.headers.token;
return {
dataSources: {
employees: new Employees(EmployeeModel),
},
token,
};
},
});
console.log(🚀 Server ready at ${url});
})();

4

Seems reasonable at a glance, though that code is really tough to read and I can’t format it in my editor without changing a bunch of characters / fixing up the paste job.

In the future, put your code between triple backticks for better formatting (```) so all of your other stuff isn’t formatted by markdown (like underscores etc.)

5

Hello, I am using mongoose, but I’d like to use the added functionality of datasources, is there a way to implement that using apollo server V4?

—Edit—
Figured it out after trials and errors.

6

Use datasources with mongoDb (mongoose) the recommended way by following the steps in the docs. Here is how I implemented mine:
My datasource:


import User from "../models/user.js";

class MongoDatasource {
  constructor(dbConnection) {
    this.dbConnection = dbConnection;
  }
  async getUser() {
    return User.find();
  }
 
  }
}
export default MongoDatasource;

My resolver:

const resolvers = {
  Query: {
    user: (_, __, { dataSources }) => {
      return dataSources.mongoDataSource.getUser();
    },

  },

My database connection

const uri = process.env.MONGODB_URI;
const dbConnection = async () => {
  await mongoose.connect(uri, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  });
};

dbConnection()
  .then(console.log("🎉 connected to database successfully"))
  .catch((error) => console. Error(error));

My contex

context: async () => {
    
    

      return {
        const { cache } = server;
       
        dataSources: {
          mongoDataSource: new MongoDatasource({ cache }),

      
        },

Use the docs to set up your server and customize according to what your application need