Finding highest value from sub-arrays in documents

Question

Let say I have the following collection:

{ _id: 1, Array: [
  { K: \"A\", V: 8 },
  { K: \"B\", V: 5 },
  { K: \"C\", V: 13 } ] }

{ _id: 2, Array: [
  { K:          


        

Answer 1

As @JohnnyHK said:

db.col.aggregate([
    {$unwind: '$Array'},
    {$group: {_id: '$_id', Array: {K: {$max: '$K'}, V: {$max: '$V'}}}}
])

Something like that.