You can use dot(.) notation to read a specific key-value pair from MongoDB collection. Let us first create a collection with documents −
> db.readSpecificKeyValueDemo.insertOne( ... { ... "_id": 100, ... "StudentDetails": ... { ... "StudentFirstName" : "David", ... "StudentLastName" :"Miller", ... "StudentAge":23, ... "StudentCountryName":"US" ... } ... } ... ); { "acknowledged" : true, "insertedId" : 100 }
Following is the query to display all documents from the collection with the help of find() method −
> db.readSpecificKeyValueDemo.find().pretty();
This will produce the following output −
{ "_id" : 100, "StudentDetails" : { "StudentFirstName" : "David", "StudentLastName" : "Miller", "StudentAge" : 23, "StudentCountryName" : "US" } }
Following is the query to read a specific key-value pair from a MongoDB collection −
> db.readSpecificKeyValueDemo.find({},{"StudentDetails.StudentCountryName":1}).pretty();
This will produce the following output −
{ "_id" : 100, "StudentDetails" : { "StudentCountryName" : "US" } }