mongodb aggregation for 2 topmost arrays with counts

Vote count: 0

I have been struggling with this for hours, and I'm sure this will be easy for some of you out there.

I have a collection with 2 topmost arrays:

{
    ...,
    topmost1: ["123", "456"],
    topmost2: ["abc","xyz"],
    ...
}

I need to aggregate counts for each where there are multiples. I've tried $unwind on both with $sum, using $size on one, but can't get the logic right.

I got this no problem: unwind one sum into a count, check for multiples then sort from most at the top to least at the bottom. But I'm having trouble with the compounds $groups and/or $unwinds. Here's the pipeline for one.

[
 { '$unwind' : '$topmost1' },
 { '$group' : { '_id' : '$topmost1', 'count': { '$sum':1 } } },
 { '$match' : { 'count' : { '$gt': 1 } } },
 { '$sort' : { 'count' : -1 } }
]

The end result should show show all records that have more than one topmost1 and topmost2 as well as their values. So I wouldn't include information for either if either one were empty.

Thanks for any help!

asked 57 secs ago

Steven Edison

Let's block ads! (Why?)

mongodb aggregation for 2 topmost arrays with counts