mongodb-query

I'm starting to use mongoDb and I'm stuck with a simple use case. Let's say I've got a collection 'aCollection' with entries such as this: { _id: ObjectId(123), lat: 48,56623, long: 2,56332 } and I want to create a new collection with entries like this: { _id: ObjectId(123), lat: 48,56623, long: 2,56332, geometry : { type: "Point", coordinates: [48,56623, 2,56332] } } I thought about the aggregation framework: db.aCollection.aggregate([{$project: { _id: 1, lat: 1, long: 1, geometry: { type: {$concat: ["Point"]}, coordinates: ["$lat", "$long"] } }}]) But it ain't working and I get this

I have following code, it insert the userName and password into database but the password is stored in plain text format. I mean when I'll look into the db I can see the inserted password. I want to store password in encrypted format MongoClient client = new MongoClient("localhost",27017); DB db = client.getDB("Test"); DBCollection collection = db.getCollection("EncryptionDemo"); BasicDBObject documentDetail = new BasicDBObject(); documentDetail.put("userName", "admin12"); documentDetail.put("password", "12345"); collection.insert(documentDetail); How can I achieve this? According to the

I have a collection like { "_id" : ObjectId("5738cb363bb56eb8f76c2ba8"), "records" : [ { "Name" : "Joe", "Salary" : 70000, "Department" : "IT" } ] }, { "_id" : ObjectId("5738cb363bb56eb8f76c2ba9"), "records" : [ { "Name" : "Henry", "Salary" : 80000, "Department" : "Sales" }, { "Name" : "Jake", "Salary" : 40000, "Department" : "Sales" } ] }, { "_id" : ObjectId("5738cb363bb56eb8f76c2baa"), "records" : [ { "Name" : "Sam", "Salary" : 90000, "Department" : "IT" }, { "Name" : "Tom", "Salary" : 50000, "Department" : "Sales" } ] } I want to have the results with the highest salary by each department {