How to convert mongodb response array from javascript object to JSON string

Question

I have written a javascript API which returns all the data from mongodb database on request. However it is sending the data s an array of objects and I want to get the simple json string. The statement returning the objects is

return db.collection('variants').find().toArray();

Do I need to append another function like JSON.stringify()? but I think that work for single object but not for array of objects as in my case.

var fetch = require('graphql-fetch');
const API_URL = `http://localhost:4000/graphql`
const query = `
{
  variants{
    VARIANT_ID
    CHROM
  }
}
`
fetch(API_URL)(query).then(data => console.log(data))

It's not JSON, it's BSON. And it's a JavaScript Object because you are using JavaScript. Of course you need to parse.\ — Neil Lunn, Jun 09 '17 at 11:53
Well in you server program connecting to MongoDB. If you are using express then there is [`res.json()`](https://expressjs.com/en/api.html#res.json). Also it it's nodejs then `.toArray()` requires a callback or promise resolution. — Neil Lunn, Jun 09 '17 at 12:09
I am using express and setup graphql API. The API in its GraphiQL windows respond fine but when I tried to fetch from client side I got an error. Let me add the fetch code too. Probably it will make more sense however ideally I would like to do it on server so that clients dont go through it — Dr. Mian, Jun 09 '17 at 12:15

score 4 · Accepted Answer · edited Jun 18 '17 at 12:20

4

Okay I found the solution. All I need is JSON.stringify(data).

var fetch = require('graphql-fetch');
const API_URL = `http://localhost:4000/graphql`
const query = `
{
  variants{
    VARIANT_ID
    CHROM
  }
}
`
fetch(API_URL)(query).then(data => console.log(JSON.stringify(data)))

edited Jun 18 '17 at 12:20

flup

26,937
7
52
74

answered Jun 11 '17 at 19:53

Dr. Mian

3,334
10
45
69

Sometimes... The simplest answer is the one you already know ;) – Daksh Jun 16 '17 at 18:01

score 0 · Answer 2 · answered Jun 16 '17 at 22:00

0

The following snippet will works properly.

fetch('/users.json')
.then(function(response) {
    return response.json()
}).then(function(json) {
    console.log('parsed json', json)
}).catch(function(ex) {
    console.log('parsing failed', ex)
})

answered Jun 16 '17 at 22:00

socrateisabot

837
2
10
28

score -3 · Answer 3 · answered Jun 09 '17 at 11:59

-3

You can use mongoexport.

In order to perform this operation you need read access to the database.

Eg: mongoexport --db database [--collection traffic] --out file.json

answered Jun 09 '17 at 11:59

Nino Matos

91
9

How to convert mongodb response array from javascript object to JSON string

3 Answers3