How do i get all keys in Mongodb collection?

mongoose mangodb
learner picture learner · Jul 8, 2015 · Viewed 9.1k times · Source

I saw few solutions but those are not exact my solution. I have a DB with name results and collection name is marks like below:

db.marks.find();
{ "_id" : ObjectId("54f57522627af4bfdcf79764"), "name" : "John", "scroe1" : 23, "score2" : 21, "score5" : 12 }
{ "_id" : ObjectId("54f5761a627af4bfdcf79765"), "name" : "Mike", "scroe2" : 22, "score3" : 20, "score4" : 22 }
{ "_id" : ObjectId("559d0bc521cb2e056507c3e3"), "name" : "Bush", "score2" : 30 }

I tried with

var doc=db.marks.findOne(); for (var key in doc) print(key);

and i got

_id
name
score1
score2
score5

But i Want all keys in collection like below:

_id, name, score1, score2, score3, score4, score5

name scroe1 score2 score3here

Answer

Matthew Antolovich picture Matthew Antolovich · Jul 11, 2015

findOne will only return the first found document. Since the first document you list does not have the score3 and score4 keys, it will not display them. If you want to show all root-level keys across all documents, you would need to iterate through all the documents in the db.

var keys = [];
db.marks.find().forEach(function(doc){
    for (var key in doc){ 
        if(keys.indexOf(key) < 0){
           keys.push(key);
        }
    }
});

print(keys);

Related questions

Find document with array that contains a specific value

If I have this schema... person = { name : String, favoriteFoods : Array } ... where the favoriteFoods array is populated with strings. How can I find all persons that have "sushi" as their favorite food using mongoose? I was hoping for something along the …

Read More
How do I update/upsert a document in Mongoose?

Perhaps it's the time, perhaps it's me drowning in sparse documentation and not being able to wrap my head around the concept of updating in Mongoose :) Here's the deal: I have a contact schema and model (shortened properties): var mongoose = …

Read More
Find MongoDB records where array field is not empty

All of my records have a field called "pictures". This field is an array of strings. I now want the newest 10 records where this array IS NOT empty. I've googled around, but strangely enough I haven't found much on this. …

Read More