如何创建这个多维数组，哈希组合？答案

【问题标题】：How do I create this multidemsional Array, Hash Combo?如何创建这个多维数组，哈希组合？
【发布时间】：2011-04-22 22:01:26
【问题描述】：

我有this data，我需要像这种类型的输出。我基本上需要所有的场地和日期以及与之相关的所有歌曲....如果有人能想到更好的结构以及如何实现它，我将非常感谢...

{ 
["Vector Arena - Auckland Central, New Zealand" => 
    { 
    "2010-10-10" => ["Enter Sandman", "Unforgiven", "And justice for all"]
    }], 
    ["Brisbane Entertainment Centre - Brisbane Qld, Austr..." => 
        { 
        "2010-10-11" => ["Enter Sandman"]
    }]
 }

到目前为止，我尝试过这个......但不确定我是否朝着正确的方向前进......

@venues = Hash.new {|hash, key| hash[key] = 0}
@requests = Request.find_all_by_artist("Metallica")
@requests.each do |request|
  @venues[request.venue] =  request.showdate
end

【问题讨论】：

标签： ruby-on-rails ruby arrays hash multidimensional-array

【解决方案1】：

这是一个有效的解决方案：

result = Hash.new {|h1, k1| h1[k1] = Hash.new{|h2, k2| h2[k2] = []}}
Request.find_all_by_artist("Metallica", 
 :select => "DISTINCT venue, showdate, LOWER(song) AS song"
).each do |req|
  result[req.venue][req.showdate] << req.song.titlecase
end

【讨论】：

【解决方案2】：

我认为你的结构不太正确。应该是这样的

[ 
{"Vector Arena - Auckland Central, New Zealand" => 
    { 
    "2010-10-10" => ["Enter Sandman", "Unforgiven", "And justice for all"]
    }}, 
    }"Brisbane Entertainment Centre - Brisbane Qld, Austr..." => 
        { 
        "2010-10-11" => ["Enter Sandman"]
    }}
 ]

试试这个代码

@venues = []
      all_venues = Request.find(:all, :select => "distinct venue, showdate")
      all_venues.each do |unique_venue|
        venue_hash = {}
        showdate_hash = {}
        song_lists = []

        requests = Request.find_all_by_venue(unique_venue.venue)  
        requests.each do |each_request|
          song_lists << each_request.song
        end
        showdate_hash[unique_venue.showdate] = song_lists

        venue_hash[unique_venue.venue] = showdate_hash
        @venues << venue_hash
      end

希望你至少能明白这一点。

【讨论】：