CODEWITHSUNDEEP
mongodbobjectid
Mazzy
Mazzy

Reputation: 14189

Referencing property in mongoDB by taking _id

I have a collection which have a document like this:

collection 1
{
  _id: ObjectID(),
  name: foo
}

I would get ObjectID of the above collection and copy into a document of another collection in order to reference correctly. Should I do simply:

db.collection1.find({name:"foo"},{_id:1})

EDIT enter image description here

Upvotes: 0

Views: 594

Answers (1)

Marc Baumbach
Marc Baumbach

Reputation: 10473

A call to find will return a cursor. Cursors works like an iterator in other languages. You can either attempt to find the first element in the cursor using the next() function and then get it's _id property or simplify your statement using findOne:

var x = db.collection1.findOne({name:"foo"}, {_id:1});
var id = x._id;

This is making an assumption that you are getting a document back from that query. You'll probably want to add a null check on x before grabbing the _id property.

Upvotes: 2

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