I want to set one of my fields as primary key. I am using MongoDB as my NoSQL.
_id
field is reserved for primary key in mongodb, and that should be a unique value. If you don't set anything to _id
it will automatically fill it with "MongoDB Id Object". But you can put any unique info into that field.
Additional info: http://www.mongodb.org/display/DOCS/BSON
Hope it helps.