// Check all the databases:
show dbs

// use new database (if doesn't exist). Adding collections will create the database automatically
use hollywood

// Check all the collections in the database hollywood
show collections

// Create collection actors and add two documents (records) in the hollywood database
db.actors.insert( { actor: "Richard Gere",  born:1949, movies: ['Pretty Woman', 'Runaway Bride', 'Chicago'] });
db.actors.insert( { actor: "Julia Roberts", born:1967, movies: ['Pretty Woman', 'Runaway Bride', 'Osage County'] });
db.actors.insert( { actor: "Meryl Streep",  born:1948, movies: ['The Devil Wears Prada', 'Osage County', 'The Iron Lady', 'The Manchurian Candidate'] });

//find all documents in the collection actors:
db.actors.find();

//find actors born after 1940:
db.actors.find({born: {$gt: 1940}});

//find actors born in 1949:
db.actors.find({born: 1949});
db.actors.find({born: {$eq: 1949}});

// find actors born in 1948, 1949
db.actors.find({born: {$in:[1949, 1948]}});

// This will remove the record for 'Richard Gere'!!
db.actors.update({actor: 'Richard Gere'}, {gender: 'male'});

// Check what happened with actors collections after last update:
db.actors.find()

// Let's return back record for 'Richard Gere'
db.actors.update( { gender: 'male'}, { actor: "Richard Gere",  born:1949, movies: ['Pretty Woman', 'Runaway Bride', 'Chicago'] });

// Better way:
db.actors.update( {_id: ObjectId("---put-record-id-here---")}, { actor: "Richard Gere",  born:1949, movies: ['Pretty Woman', 'Runaway Bride', 'Chicago'] });

// This will not work!! You need to use ObjectId instead of ID
db.actors.update( {_id: "---put-record-id-here---"}, { actor: "Richard Gere",  born:1949, movies: ['Pretty Woman', 'Runaway Bride', 'Chicago'] });


// Fix year for Meryl - increase it by 1
db.actors.update({actor: 'Meryl Streep'}, {$inc: {born: 1}});

// Update just the name:
db.actors.update({actor: 'Richard Gere'}, {$set: {actor: 'Richard Gere III'}});

// Add extra attribute:
db.actors.update({actor: 'Meryl Streep'}, {$set: {gender: 'Female'}});

// Add extra movie to Meryl Streep:
db.actors.update({actor: 'Meryl Streep'}, {$push: {movies: 'Out of Africe'}});

// List all the actors in the collection:
db.actors.find({}, {actor: 1});

// Sort documents using two keys: born (ascending) and actor (descending and ascending)
db.actors.find().sort({born: 1, actor: -1});
db.actors.find().sort({born: 1, actor: 1});

// We want to list now movies and actors played in each movie (as an array)
// Add map and reduce functions:
map = function() {
  for(var i in this.movies){
    key = { movie: this.movies[i] };
    value = { actors: [ this.actor ] };
    emit(key, value);
  }
}

reduce = function(key, values) {
  actor_list = { actors: [] };
  for(var i in values) {
    actor_list.actors = values[i].actors.concat(actor_list.actors);
  }
  return actor_list;
}


// Create new collection 'movies':
db.actors.mapReduce(map, reduce, "movies");

// Check that you have now two collections: movies and actors:
show collections

// List all the movies in the just created movies collection:
db.movies.find();

// Drop collection movies:
db.movies.drop();

// Check that you have database hollywood selected
db

// Drop selected database hollywood:
db.dropDatabase();