How to access the response from .find in a JSON object with Node.js

Question

I have a "pseudo" database, similar to a collection in MongoDB which has a JSON object.

export const roles = [
  { 
    _id: "870c4350-3cf5-4f35-8429-513bd86c6734",
    programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968",
    profileId: "3cbaadcf-41e1-423b-aa6a-b3fb401df148",
    fullName: null,
    jobTitle: "Regional Implementation Executive",
    department: "Electronics",
    favouriteColour: "salmon",
  },
  {
    _id: "ed231d80-f22b-4f52-bd94-9d58a2fbdbc8",
    programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968",
    profileId: "1bc21aff-896f-44da-8436-a1604a626c39",
    fullName: null,
    jobTitle: "Direct Identity Strategist",
    department: "Beauty",
    favouriteColour: "silver",
  },
  {
    _id: "c6804099-150f-401b-9e3d-15945085fdde",
    programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968",
    profileId: "580acb22-46f1-4bc3-b74f-606c933e43a0",
    fullName: null,
    jobTitle: "Investor Brand Developer",
    department: "Garden",
    favouriteColour: "cyan",
  },
  {
    _id: "45119579-ec48-4d7b-b4e3-656d2ad5468b",
    programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968",
    profileId: "98793f3f-2f03-49a8-b77e-e96e0eff1b28",
    fullName: null,
    jobTitle: "National Research Facilitator",
    department: "Home",
    favouriteColour: "turquoise",
  }
];

Using .find I am trying to get all the items with fullName: null and programId: 'e3e20d57-571d-45ab-b13a-b07d29fcf968 .

This is my code where I am trying to access the response with .then() as .find is an asynchronous method.

  await roles.find({
        fullName: null,
        programId: 'e3e20d57-571d-45ab-b13a-b07d29fcf968'

      }).then((res.update(
        {
          programId: x._id,
        },
        {
          fullName: x.name,
        })
     ))
     .catch(err => console.log(err));

But, I am unable to access the response as I get an error saying res is not defined .

ERROR.

(node:99872) UnhandledPromiseRejectionWarning: ReferenceError: res is not defined
    at callback (/Users/Rahul/PersonalProjects/js-test/redact-surnames.js:28:20)
    at Object.forEach (/Users/Rahul/PersonalProjects/js-test/lib/collections.js:16:13)
    at _default (/Users/Rahul/PersonalProjects/js-test/redact-surnames.js:6:3)
(node:99872) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
(node:99872) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

I know this query with .find works as when I assign the response to a const and then console.log({ }); I see it print fine.

const response = await roles.find({
    fullName: null,
    programId: 'e3e20d57-571d-45ab-b13a-b07d29fcf968'
  });
  console.log({ response });

However, I cannot access it with .then and res , maybe I am making a mistake on the syntax but any help would be highly appreciated.

Answer 1

If you are trying to get all the items inside roles that matches the condition

fullName === null && programId === 'e3e20d57-571d-45ab-b13a-b07d29fcf968'

you can simply use filter to iterate over the array and get the filtered results.

Here's a good article:

https://medium.com/poka-techblog/simplify-your-javascript-use-map-reduce-and-filter-bd02c593cc2d

But if you use .find() , it will return the first value that corresponds to the passed condition. YOu can use .find() if that's what you are after.

 const roles = [ { _id: "870c4350-3cf5-4f35-8429-513bd86c6734", programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968", profileId: "3cbaadcf-41e1-423b-aa6a-b3fb401df148", fullName: null, jobTitle: "Regional Implementation Executive", department: "Electronics", favouriteColour: "salmon", }, { _id: "ed231d80-f22b-4f52-bd94-9d58a2fbdbc8", programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968", profileId: "1bc21aff-896f-44da-8436-a1604a626c39", fullName: null, jobTitle: "Direct Identity Strategist", department: "Beauty", favouriteColour: "silver", }, { _id: "c6804099-150f-401b-9e3d-15945085fdde", programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968", profileId: "580acb22-46f1-4bc3-b74f-606c933e43a0", fullName: null, jobTitle: "Investor Brand Developer", department: "Garden", favouriteColour: "cyan", }, { _id: "45119579-ec48-4d7b-b4e3-656d2ad5468b", programId: "e3e20d57-571d-45ab-b13a-b07d29fcf968", profileId: "98793f3f-2f03-49a8-b77e-e96e0eff1b28", fullName: null, jobTitle: "National Research Facilitator", department: "Home", favouriteColour: "turquoise", } ]; // Using filter method const filterResult = roles.filter((role)=> role.fullName === null && role.programId ==='e3e20d57-571d-45ab-b13a-b07d29fcf968'); // note: result here is an array of object/s console.log(filterResult); // Using find method const findResult = roles.find((role)=> role.fullName === null && role.programId ==='e3e20d57-571d-45ab-b13a-b07d29fcf968'); // note: result here is an object console.log(findResult);

Answer 2

i think its causing the error,

await roles.find({
    fullName: null,
    programId: 'e3e20d57-571d-45ab-b13a-b07d29fcf968'

  }).then((res.update({  // <
    programId: x._id,    // <
  }, {                   // <
    fullName: x.name,    // <
  })))                   // <
  .catch(err => console.log(err));

I think, ur trying to do something like this,

.then(res =>
  res.update({
    programId: x._id
  }, {
    fullName: x.name
  })
)