Use forEach and check for the different elements and use save() along with some condition. Let us create a collection with documents −
> db.demo646.insertOne( ... { ... ... "Information": [ ... { id: 100, Name:"Chris" }, ... { id: 100, Name:"Chris" }, ... { id: 101, Name:"David" }, ... { id: 100, Name:"Chris" } ... ], ... "different": [] ... } ... ) { "acknowledged" : true, "insertedId" : ObjectId("5e9c82ec6c954c74be91e6ed") }
Display all documents from a collection with the help of find() method −
> db.demo646.find().pretty();
This will produce the following output −
{ "_id" : ObjectId("5e9c82ec6c954c74be91e6ed"), "Information" : [ { "id" : 100, "Name" : "Chris" }, { "id" : 100, "Name" : "Chris" }, { "id" : 101, "Name" : "David" }, { "id" : 100, "Name" : "Chris" } ], "different" : [ ] }
Following is the query to move elements to another array −
> db.demo646.find({}).forEach(function(d) { ... d.different = d.Information.filter(function(v) { return v.id == 101 }) ... d.Information = d.Information.filter(function(v) { return v.id != 101 }) ... db.demo646.save(d) ... } ... )
Display all documents from a collection with the help of find() method −
> db.demo646.find().pretty();
This will produce the following output −
{ "_id" : ObjectId("5e9c82ec6c954c74be91e6ed"), "Information" : [ { "id" : 100, "Name" : "Chris" }, { "id" : 100, "Name" : "Chris" }, { "id" : 100, "Name" : "Chris" } ], "different" : [ { "id" : 101, "Name" : "David" } ] }