MongoDB-তে নেস্টেড নথিগুলি একত্রিত করতে, আপনি $group ব্যবহার করতে পারেন। আসুন প্রথমে নথি-
সহ একটি সংগ্রহ তৈরি করি> db.aggregateDemo.insertOne( ... { ... "ProductInformation": [ ... { ... "Product1": [ ... { ... Amount: 50 ... }, ... { ... Amount: 90 ... }, ... { ... Amount: 30 ... } ... ] ... }, ... { ... "Product1": [ ... { ... Amount: 200 ... }, ... { ... Amount: 30 ... }, ... { ... Amount: 40 ... } ... ] ... }, ... { ... "Product1": [ ... { ... Amount: 150 ... }, ... { ... Amount: 190 ... }, ... { ... Amount: 198 ... } ... ] ... } ... ... ] ... }); { "acknowledged" : true, "insertedId" : ObjectId("5e04df58150ee0e76c06a04d") } > db.aggregateDemo.insertOne( ... { ... "ProductInformation": [ ... { ... "Product1": [ ... { ... Amount: 100 ... }, ... { ... Amount: 1002 ... }, ... { ... Amount: 78 ... } ... ] ... }, ... { ... "Product1": [ ... { ... Amount: 75 ... }, ... { ... Amount: 400 ... }, ... { ... Amount: 600 ... } ... ] ... }, ... { ... "Product1": [ ... { ... Amount: 700 ... }, ... { ... Amount: 500 ... }, ... { ... Amount: 600 ... } ... ] ... } ... ... ] ... }); { "acknowledged" : true, "insertedId" : ObjectId("5e04df93150ee0e76c06a04e") }
Find() পদ্ধতির সাহায্যে একটি সংগ্রহ থেকে সমস্ত নথি প্রদর্শন করার জন্য নিম্নলিখিত প্রশ্ন রয়েছে -
> db.aggregateDemo.find().pretty();
এটি নিম্নলিখিত আউটপুট −
তৈরি করবে{ "_id" : ObjectId("5e04df58150ee0e76c06a04d"), "ProductInformation" : [ { "Product1" : [ { "Amount" : 50 }, { "Amount" : 90 }, { "Amount" : 30 } ] }, { "Product1" : [ { "Amount" : 200 }, { "Amount" : 30 }, { "Amount" : 40 } ] }, { "Product1" : [ { "Amount" : 150 }, { "Amount" : 190 }, { "Amount" : 198 } ] } ] } { "_id" : ObjectId("5e04df93150ee0e76c06a04e"), "ProductInformation" : [ { "Product1" : [ { "Amount" : 100 }, { "Amount" : 1002 }, { "Amount" : 78 } ] }, { "Product1" : [ { "Amount" : 75 }, { "Amount" : 400 }, { "Amount" : 600 } ] }, { "Product1" : [ { "Amount" : 700 }, { "Amount" : 500 }, { "Amount" : 600 } ] } ] }
এখানে নেস্টেড ডকুমেন্ট −
একত্রিত করার জন্য প্রশ্ন রয়েছে> db.aggregateDemo.aggregate([ ... { ... $unwind:"$ProductInformation" ... }, ... { ... $unwind:"$ProductInformation.Product1" ... }, ... { ... $group:{ ... _id:null, ... MaximumAmount:{ ... $max:"$ProductInformation.Product1.Amount" ... } ... } ... } ... ]);
এটি নিম্নলিখিত আউটপুট −
তৈরি করবে{ "_id" : null, "MaximumAmount" : 1002 }