How to use mongoose findOne

Question

I have the below schema (apologies that it is in coffeescript)

Schema = mongoose.Schema

AuthS = new Schema
    auth:   {type: String, unique: true}
    nick:   String
    time:   Date
Auth = mongoose.model 'Auth', AuthS

I simply want to recover one record which is definitely in my database:

Auth.findOne({nick: 'noname'}, function(obj) { console.log(obj); });

Unfortunately this always logs null. db.auths.findOne({nick: 'noname'}) in mongo shell always returns a value. What is going on?

score 109 · Accepted Answer · answered Aug 11 '11 at 22:20

109

Found the problem, need to use function(err,obj) instead:

Auth.findOne({nick: 'noname'}, function(err,obj) { console.log(obj); });

answered Aug 11 '11 at 22:20

Callum Rogers

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When I use `findOne` like this I get my data successfully but `obj` is not a `Document` object. When I try `obj.nick` and `obj[nick]` I get undefined. When I try `obj.get('nick')` I get object does not have method get. I tried many JSON conversions and creating a `doc = new Document(obj)`. I also tried `doc.toObject(obj)` and `doc.set(obj)`; – Jonathan Czitkovics Aug 26 '13 at 12:04
2

@JonathanCzitkovics I think that if you do obj.toObject() that would give you what you were looking for. – Guy Jan 05 '14 at 07:03
5

When the operation executes succesfully (err is null), but there is no match, the document will be null too. – László Kardinál Feb 23 '16 at 13:18
But how are you getting the object inside of findOne? I am assuming this info would be in a route. req.body? – Winnemucca Apr 23 '17 at 07:27
@JonathanCzitkovics . Thank you. But please let me know the reason. Only for one project i am using like this for others i can just use . symbol – user1187 Nov 20 '17 at 11:51

score 15 · Answer 2 · edited Jan 30 '22 at 04:15

Mongoose basically wraps mongodb's api to give you a pseudo relational db api so queries are not going to be exactly like mongodb queries. Mongoose findOne query returns a query object, not a document. You can either use a callback as the solution suggests or as of v4+ findOne returns a thenable so you can use .then or await/async to retrieve the document.

// thenables
Auth.findOne({nick: 'noname'}).then(err, result) {console.log(result)};
Auth.findOne({nick: 'noname'}).then(function (doc) {console.log(doc)});

// To use a full fledge promise you will need to use .exec()
var auth = Auth.findOne({nick: 'noname'}).exec();
auth.then(function (doc) {console.log(doc)});

// async/await
async function async auth() {
  const doc = await Auth.findOne({nick: 'noname'}).exec();
  return doc;
}
auth();

See the docs if you would like to use a third party promise library.

score 10 · Answer 3 · answered May 20 '19 at 07:07

In my case same error is there , I am using Asyanc / Await functions , for this needs to add AWAIT for findOne

Ex:const foundUser = User.findOne ({ "email" : req.body.email });

above , foundUser always contains Object value in both cases either user found or not because it's returning values before finishing findOne .

const foundUser = await User.findOne ({ "email" : req.body.email });

above , foundUser returns null if user is not there in collection with provided condition . If user found returns user document.

score 2 · Answer 4 · edited Jul 28 '16 at 19:01

2

You might want to consider using console.log with the built-in "arguments" object:

console.log(arguments); // would have shown you [0] null, [1] yourResult

This will always output all of your arguments, no matter how many arguments you have.

edited Jul 28 '16 at 19:01

John Slegers

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answered Jul 28 '16 at 18:53

Neil Gaetano Lindberg

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score 0 · Answer 5 · answered Apr 09 '18 at 11:56

0

Use obj[0].nick and you will get desired result,

answered Apr 09 '18 at 11:56

NaturalCoder

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How to use mongoose findOne

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