Sort records into buckets with Rails - ruby-on-rails

Question

I have a Game model that has a datetime, storing the date and time the game will be played. I'd like to put those records into an array of arrays of each date.
Example of a possible outcome array:
[
[
#<Game id: 7, datetime: "2014-03-03 05:30:00">,
#<Game id: 12, datetime: "2014-03-03 11:30:00">,
#<Game id: 14, datetime: "2014-03-03 12:30:00">,
#<Game id: 17, datetime: "2014-03-03 12:45:00">
],
[
#<Game id: 1, datetime: "2014-04-06 05:30:00">,
#<Game id: 2, datetime: "2014-04-06 11:30:00">,
#<Game id: 4, datetime: "2014-04-06 12:30:00">,
#<Game id: 7, datetime: "2014-04-06 12:45:00">
]
]
Here's what I'm trying so far
#games = Array.new
Game.all.each do |game|
# in my model I have a function date that gets the date part of my datetime
quit = false
index = 0
while !quit do
if index < #games.length
quit = true
#games << [game]
elsif #games[index].first.date == game.date
quit = true
#games[index] << game
end
end
end
But this seems not very ruby-like and probably not the most efficient way. Is there a better approach for this?

Answer 1

This is probably not the most efficient way to do this, but it is short and readable:
#games = {}
Game.all.each do |game|
#games[game.date] = [] if !#games.has_key? game.date
#games[game.date] << game
end
#games = #games.values
Note that it is idiomatic Ruby to use array and hash literals [] and {} instead of their respective Array.new and Hash.new constructors.
Update
Here's an even better way, using the group_by method of Enumerable, which collections can include as a module:
#games = Game.all.group_by { |game| game.date }
Note that this will return a hash using the dates as keys, but you can easily turn this into an array by calling the values method on a hash.