levicook

// ------------------------------------------------------------------
// Friend collection, where _id is a user.Id and Friends is a list, of user.Id.
// Note: friending and unfriending is a two step operation in this scheme:

> db.friends.find()
{ "_id" : 1, "friends" : [    2, 3, 4    ] }
{ "_id" : 2, "friends" : [ 1,    3,    5 ] }
{ "_id" : 3, "friends" : [ 1, 2,    4, 5 ] }
{ "_id" : 4, "friends" : [ 1,    3,    5 ] }
{ "_id" : 5, "friends" : [    2, 3, 4    ] }