copy from Janx Spirit http://janxspirit.blogspot.jp/2011/11/introduction-to-casbah-scala-mongodb.html

mongodb_snipets.scala

// copy from Janx Spirit http://janxspirit.blogspot.jp/2011/11/introduction-to-casbah-scala-mongodb.html

//connect to a MongoDB server
val mongo = MongoConnection("anduin")
 
//create/connect to a collection
val coll = mongo("casbah_examples")("movies")
 
//drop collection
coll.dropCollection
 
//create some documents
val pf = MongoDBObject("title" -> "Pulp Fiction",
                       "director" -> "Quentin Tarantino",
                       "foo" -> "bar",
                       "actors" -> List("John Travolta", "Samuel L Jackson"),
                       "year" -> 1994)
 
val sw = MongoDBObject("title" -> "Star Wars",
                       "director" -> "George Lucas",
                       "cast" -> List("Harrison Ford", "Carrie Fisher"),
                       "year" -> 1977)
 
 val fc = MongoDBObject("title" -> "Fight Club",
                       "director" -> "David Fincher",
                       "cast" -> List("Brad Pitt", "Edward Norton"),
                       "year" -> 1999)
 
//add some documents
coll += pf
coll += sw
coll += fc
val pfid = MongoDBObject("_id" -> pf.get("_id"))
 
//update a document
//increment a value (or set it if the value does not exist)
coll.update(pfid, $inc("likes" -> 1))
 
//set a value
coll.update(pfid, $set("year" -> 1994))
 
//remove a field
coll.update(pfid, $unset("foo"))
 
//add a value to an array - create it if need be
coll.update(pfid, $push("comebackKids" -> "John Travolta"))
 
//add a bunch of values to an array
coll.update(pfid, $pushAll("comebackKids" -> ("Bruce Willis", "Uma Thurman")))
 
//add to a set (only adds values that were not there already)
coll.update(pfid, $addToSet("actors") $each("John Travolta","Groucho Marx","Harpo Marx","Alyssa Milano","Bruce Willis","Uma Thurman", "Jim Carrey"))
 
//remove last element of an array - use -1 to remove the first element
coll.update(pfid, $pop("actors" -> 1))
 
//remove matching elements from a field
coll.update(pfid, $pull("actors" -> "Alyssa Milano"))
 
//remove more than one matching element from a field
coll.update(pfid, $pullAll("actors" -> ("Groucho Marx", "Harpo Marx")))
 
//rename a field
coll.update(pfid, $rename("actors" -> "cast"))
 
//query documents
//find one by an exact field match
coll.findOne(MongoDBObject("title" -> "Star Wars"))
 
//find by regex
coll.find(MongoDBObject("title" -> ".*F".r))
 
//leave out the ids
coll.find(MongoDBObject(),MongoDBObject("_id" -> 0))
 
//include only certain fields without ids
coll.find(MongoDBObject(), MongoDBObject("title" -> 1, "cast" -> 1, "_id" -> 0))
 
//find most recent
coll.find(MongoDBObject()).sort(MongoDBObject("year" -> -1)).limit(1)
 
//remove
coll.remove(MongoDBObject("title" -> "Fight Club"))