Node.js / Mongodb insert callback returning undefined

Question

when I run the simple code below to insert a new document:

collectionUsers.insert({'name':'john'},function(err,records){
    if (err) throw err;
    console.log("Id of new document added =  " + records[0]._id);
});

I get the following errors:

catch(err) { process.nextTick(function() { throw err}); }
                                             ^
TypeError: Cannot read property '_id' of undefined

Doesn't the callback function return an array? I'm just trying to get the id of the new document and save it in a variable for future use. Thanks for your help.

Alternatively, if I use insertOne instead, I get this output: Id of new document added = {"ok":1,"n":1}

But I want to use insert...

As the documentation states, the callback gets called with a insertWriteOpResultObject object. — robertklep
– robertklep, Commented Jan 1, 2016 at 8:09

Jagdish Idhate · Accepted Answer · 2016-01-01 08:02:32Z

8

There is ops object in records which contains inserted doc/docs.

Try:

collectionUsers.insert({'name':'john'},function(err,records){
   // You can explore more here
   console.log("record contents",JSON.stringify(records,null,4));
   // Desired output
   console.log("Id of new document added =  " + records.ops[0]._id);
});

edited Jan 1, 2016 at 8:02

answered Jan 1, 2016 at 7:07

Jagdish Idhate

7,7529 gold badges37 silver badges58 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

cmonkey Over a year ago

When I add you line I get this output: record contents [object Object]...why doesn't records just give me the document? I have seen many examples with the same code and they don't return any errors.

Jagdish Idhate Over a year ago

Answer edited. Its npm mongodb library implementation which give you this results. alternatively you can use npm mongoose which is wrapper over mongodb npm. It will give you desired results, more info here

cmonkey Over a year ago

With your stringify code I get this (same as if I were to use insertOne): { "ok": 1, "n": 1 }

robertklep Over a year ago

@user2285490 mongoose is much more than just a wrapper. It's a great library, but perhaps a bit overkill just to get the desired result :-) The inserted document is available through records.ops, as you suggest.

cmonkey Over a year ago

sorry guys...so why cant records access the name field?

|

cmonkey · Accepted Answer · 2016-01-01 20:11:23Z

0

Thanks a lot user2285490 and robertklep. I finally realized what the ops object in record is. This is the api documentation for future reference:

http://mongodb.github.io/node-mongodb-native/2.0/api/Collection.html#~insertWriteOpCallback

answered Jan 1, 2016 at 20:11

cmonkey

131 silver badge5 bronze badges

Collectives™ on Stack Overflow

Node.js / Mongodb insert callback returning undefined

2 Answers 2

6 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related