For nested queries, let us first create a collection with documents −
> db.demo492.insertOne({ ... "ProductDetails" : ... { ... "StockDetails" : [ ... { "ProductName" : "Product-1" }, ... {"ProductName" : "Product-2"}, ... { "ProductName" : "Product-3"} ... ... ] ... ... } ... }); { "acknowledged" : true, "insertedId" : ObjectId("5e849db8b0f3fa88e22790c2") } > > > > db.demo492.insertOne({ ... "ProductDetails" : ... { ... "StockDetails" : [ ... { "ProductName" : "Product-4" }, ... {"ProductName" : "Product-5"}, ... { "ProductName" : "Product-6"} ... ... ] ... ... } ... }); { "acknowledged" : true, "insertedId" : ObjectId("5e849dceb0f3fa88e22790c3") }
Display all documents from a collection with the help of find() method −
> db.demo492.find();
This will produce the following output −
{ "_id" : ObjectId("5e849db8b0f3fa88e22790c2"), "ProductDetails" : { "StockDetails" : [ { "ProductName" : "Product-1" }, { "ProductName" : "Product-2" }, { "ProductName" : "Product3" } ] } } { "_id" : ObjectId("5e849dceb0f3fa88e22790c3"), "ProductDetails" : { "StockDetails" : [ { "ProductName" : "Product-4" }, { "ProductName" : "Product-5" }, { "ProductName" : "Product6" } ] } }
Following displays nested queries in MongoDB using dot notation to fetch a specific document −
> db.demo492.find({ "ProductDetails.StockDetails.ProductName":"Product-1"});
This will produce the following output −
{ "_id" : ObjectId("5e849db8b0f3fa88e22790c2"), "ProductDetails" : { "StockDetails" : [ { "ProductName" : "Product-1" }, { "ProductName" : "Product-2" }, { "ProductName" : "Product3" } ] } }