MongoDB: Search minimum, maximum in nested object with dynamic field name -

i have query minimum query , maximum query on below sample data set. in case fields names dynamic, below product_1, product_2...

{     "_id" : numberlong(540),     "product_1" : {             "ordercancelled" : 0,             "orderdelivered" : 6     },     "product_2" : {             "ordercancelled" : 3,             "orderdelivered" : 16     },     "product_3" : {             "ordercancelled" : 5,             "orderdelivered" : 11     } } 

i not getting idea how can in mongo field names dynamic, means in future there may other products created product_4 , product_5 same id.

i need query gives me minimum value orderdelivered , maximum value ordercancelled, example in above document result orderdelivered:16 & ordercancelled:0 .
idea.

you should restructure document product documents in array:

{     "_id": numberlong(540),     products: [         {             "name": "product_1",             "ordercancelled": 0,             "orderdelivered": 6         },         {             "name": "product_2",             "ordercancelled": 3,             "orderdelivered": 16         },         {             "name": "product_3",             "ordercancelled": 5,             "orderdelivered": 11         }     ] } 

then you'll able issue normal max/min queries this:

db.test.aggregate([     {            $match: { "_id" : numberlong(540) }     },     {         $unwind: "$products"     },     {         $group: {             _id: "$_id",             mindelivered: { $min: "$products.orderdelivered" },             maxcancelled: { $max: "$products.ordercancelled" }         }     } ])