How to copy a collection from one database to another in MongoDB

Question

Is there a simple way to do this?

Answer 1

In my case, I had to use a subset of attributes from the old collection in my new collection. So I ended up choosing those attributes while calling insert on the new collection.

db..find().forEach(function(doc) { 
    db..insert({
        "new_field1":doc.field1,
        "new_field2":doc.field2,
        ....
    })
});`