如何创建这个multidemsional数组，散列组合？ [英] How do I create this multidemsional Array, Hash Combo?

问题描述

我有这个数据，我需要这样类型的输出的输出。我基本上需要都场地和的日期和与之关联的....如果有人能想到更好的结构，以及如何实现它，我会很感激的所有歌曲...

  {
[矢量竞技场 - 奥克兰，新西兰=＆GT;
    {
    2010-10-10=＆GT; [进入Sandman，不可饶恕，和正义]
    }]，
    [布里斯班娱乐中心 - 布里斯班昆士兰，Austr ......=＆GT;
        {
        2010-10-11=＆GT; [进入Sandman]
    }]
 }
 

到目前为止，我想这...不知道如果我在正确的方向移动我..

  @venues = Hash.new {|哈希键|哈希[关键] = 0}
@requests = Request.find_all_by_artist（Metallica的）
@ requests.each做|请求|
  @venues [request.venue] = request.showdate
结束
 

解决方案

下面是一个有效的解决方案：

 结果= Hash.new {| H1，K1 | H1 [K] = {Hash.new | H2，K2 | H2 [K2] = []}}
Request.find_all_by_artist（Metallica的
 ：选择=＆GT; DISTINCT会场，showdate相​​似，LOWER（歌曲）AS歌
）。每个做| REQ |
  结果[req.venue] [req.showdate＆LT;＆LT; req.song.titlecase
结束
 

I have this data and i need an output like this type of output.. I basically need to have all the venues and their dates and all the songs associated to them ....if anyone can think of a better structure and how to achieve it I would be very thankful...

{ 
["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"]
    }]
 }

so far i tried this...and not sure if i am moving in the right direction..

@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

解决方案

Here is an efficient solution:

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

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