CODEWITHSUNDEEP
node.jsmongodb
Tarang
Tarang

Reputation: 75945

MongoDB Node findone how to handle no results?

Im using the npm mongodb driver with node.

I have

collection.findOne({query}, function(err, result) {
    //do something
}

The problem is say I dont have any results, err is still null whether I find a result or don't. How would I know that there were no results found with the query?

I've also tried

info = collection.findOne(....

But the info is just undefined (it looked asynchronous so I didn't think it was the way to go anyway..)

Upvotes: 54

Views: 55604

Answers (6)

user2779653
user2779653

Reputation: 927

nowadays - since node 8 - you can do this inside an async function:

async function func() {
  try {
    const result = await db.collection('xxx').findOne({query});
    if (!result) {
      // no result
    } else {
      // do something with result
    }
  } catch (err) {
    // error occured
  }
}

Upvotes: 4

Stepan Yakovenko
Stepan Yakovenko

Reputation: 9206

All of these answers below are outdated. findOne is deprecated. Lastest 2.1 documentation proposes to use

find(query).limit(1).next(function(err, doc){
   // handle data
})

Upvotes: 9

parkerproject
parkerproject

Reputation: 2186

collection.findOne({query}, function(err, result) {
   if (err) { /* handle err */ }

   if (result.length === 0) {
    // we don't have result
   }
}

Upvotes: -9

sospedra
sospedra

Reputation: 14734

Simply as:

collection.findOne({query}, function(err, result) {
    if (!result) {
        // Resolve your query here
    }
}

Upvotes: 5

Martin
Martin

Reputation: 5322

If result is null then mongo didn't find a document matching your query. Have tried the query from the mongo shell?

Upvotes: 0

jmar777
jmar777

Reputation: 39649

Not finding any records isn't an error condition, so what you want to look for is the lack of a value in result. Since any matching documents will always be "truthy", you can simply use a simple if (result) check. E.g.,

collection.findOne({query}, function(err, result) {
    if (err) { /* handle err */ }

    if (result) {
        // we have a result
    } else {
        // we don't
    }
}

Upvotes: 77

Related Questions