How to convert mongodb response array from javascript object to JSON string - Stack Overflow

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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))

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))

• javascript
• json
• mongodb
• bson

Share Improve this question Follow edited Jun 11, 2017 at 19:52 drmaa asked Jun 9, 2017 at 11:45 drmaadrmaa 3,6841010 gold badges5353 silver badges7777 bronze badges 5

• 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 Commented Jun 9, 2017 at 11:53
• On client side or server side? – drmaa Commented Jun 9, 2017 at 12:07
• Well in you server program connecting to MongoDB. If you are using express then there is res.json(). Also it it's nodejs then .toArray() requires a callback or promise resolution. – Neil Lunn Commented Jun 9, 2017 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 – drmaa Commented Jun 9, 2017 at 12:15
• Just stringify the object... – Andrew Li Commented Jun 11, 2017 at 23:38

Add a ment  | 

3 Answers 3

Sorted by: Reset to default 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)))

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)
})

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

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