query mongodb inside nested array of objects

Question

I have entry in a collection like this one:

{
   "overlaps": [
      {"BB1": "itemA", "iou": 0.1, "BB2": "itemB"},
      {"BB1": "itemB", "iou": 0.45, "BB2": "itemC"}
   ],
   "elemID": 1,
   "otherfield2": "whateverelse"
}

I want to find entries that have element in the overlap array where overlaps.BB1:"itemA" and overlaps.BB2:"itemC". But for the same element in the overlaps array.

For instance, the example given here should not be retrieved, because I have overlaps.BB1:"itemA" and overlaps.BB2:"itemC", but not in the same element.

A valid element would be:

{
   "overlaps": [
      {"BB1": "itemA", "iou": 0.1, "BB2": "itemC"},
      {"BB1": "itemB", "iou": 0.45, "BB2": "itemC"}
   ],
   "elemID": 2,
   "otherfield2": "whateverelse"
}

I have tried this but does not work

cursor = record1.find({"$and": [{"overlaps.BB1":"itemA"},{"overlaps.BB2":"itemC"}]})

How can I make this work? Or should I change my data structure in order to be able to perform such queries?

Thanks

Ashh · Accepted Answer · 2018-05-22 16:24:53Z

1

You should use $elemMatch to get the result

db.collection.find({
  overlaps: {
    $elemMatch: {
      BB1: "itemA",
      BB2: "itemC"
    }
  }
})

answered May 22, 2018 at 16:24

Ashh

46.6k16 gold badges111 silver badges137 bronze badges

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

Collectives™ on Stack Overflow

query mongodb inside nested array of objects

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related