NodeJS + MongoDB: Getting data from collection with findOne ()

Question

I have a collection "companies" with several objects. Every object has "_id" parameter. I'm trying to get this parameter from db: ``` app.get('/companies/:id',function(req,res){ db.collection("companies",function(err,collection){ console.log(req.params.id); collection.findOne({_id: req.params.id},function(err, doc) { if (doc){ console.log(doc._id); } else { console.log('no data for this company'); } }); }); }); ``` So, I request companies/4fcfd7f246e1464d05000001 (4fcfd7f246e1464d05000001 is _id-parma of a object I need) and findOne returns nothing, that' why console.log('no data for this company'); executes. I'm absolutely sure that I have an object with _id="4fcfd7f246e1464d05000001". What I'm doing wrong? Thanks! However, I've just noticed that id is not a typical string field. That's what mViewer shows: ``` "_id": { "$oid": "4fcfd7f246e1464d05000001" }, ``` Seems to be strange a bit...

Accepted Answer

You need to construct the ObjectID and not pass it in as a string. Something like this should work:

```
var BSON = require('mongodb').BSONPure;
var obj_id = BSON.ObjectID.createFromHexString("4fcfd7f246e1464d05000001");
```

Then, try using that in your find/findOne.

Edit: As pointed out by Ohad in the comments (thanks Ohad!), you can also use:

```
new require('mongodb').ObjectID(req.params.id)
```

Instead of `createFromHexString` as outlined above.

NodeJS + MongoDB: Getting data from collection with findOne ()

Solution

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