如何有條件地合併散列並添加值？

Question

我卡住合併一些哈希來得到我需要的結果。

散列包含訂單總價格的細目，項目價格，稅收，&送貨，訂購中的所有訂單。我試圖動態執行此操作，因爲並非所有訂單都收取稅費，甚至不需要稅或運費。

這裏就是我稱之爲「最壞的情況」我正在處理：

#First order - has charges for Canadian GST and HST 
{:orderhdr_id=>17654122, :order_item_seq=>1, :order_item_amt_break_seq=>1, :order_item_break_type=>0, :local_amount=>8.16, :base_amount=>8.16, :orig_base_amount=>149, :tax_delivery=>0, :tax_active=>0} 
{:orderhdr_id=>17654122, :order_item_seq=>1, :order_item_amt_break_seq=>2, :order_item_break_type=>1, :local_amount=>0.41, :base_amount=>0.41, :state=>"ON", :tax_type=>"GST", :tax_rate_category=>"STD", :orig_base_amount=>7.45, :tax_rate=>5, :tax_delivery=>0, :tax_active=>1, :tx_incl=>1} 
{:orderhdr_id=>17654122, :order_item_seq=>1, :order_item_amt_break_seq=>3, :order_item_break_type=>1, :local_amount=>0.65, :base_amount=>0.65, :state=>"ON", :tax_type=>"HST", :tax_rate_category=>"STD", :orig_base_amount=>11.92, :tax_rate=>8, :tax_delivery=>0, :tax_active=>1, :tx_incl=>1} 
#Second order - has only one charge for tax 
{:orderhdr_id=>1815296, :order_item_seq=>1, :order_item_amt_break_seq=>1, :order_item_break_type=>0, :local_amount=>76.52, :base_amount=>76.52, :orig_base_amount=>99.95, :tax_delivery=>0, :tax_active=>0} 
{:orderhdr_id=>1815296, :order_item_seq=>1, :order_item_amt_break_seq=>2, :order_item_break_type=>1, :local_amount=>4.59, :base_amount=>4.59, :orig_base_amount=>6, :tax_delivery=>0, :tax_active=>1} 
#Third order - has charge for shipping 
{:orderhdr_id=>6112412, :order_item_seq=>1, :order_item_amt_break_seq=>1, :order_item_break_type=>0, :local_amount=>21.34, :base_amount=>21.34, :orig_base_amount=>99.95, :tax_delivery=>0, :tax_active=>0} 
{:orderhdr_id=>6112412, :order_item_seq=>1, :order_item_amt_break_seq=>2, :order_item_break_type=>2, :local_amount=>4.7, :base_amount=>4.7, :orig_base_amount=>22, :tax_delivery=>0, :tax_active=>0} 

的:order_item_break_type決定了它是什麼類型的收費，項目，稅收，航運。

如果:order_item_break_type爲0或2，然後從:orig_base_amount減去:base_amount並將其添加到該中斷類型的整體總。對於:order_item_break_type等於1，我需要總結:orig_base_amount和:base_amount,的差異，但是我需要將不同的稅分開。

因此，這裏是我應該與上面的命令結束了一下：

:break_type = 0 | total = 242.88 
:break_type = 1, :state = ON, :tax_type = GST, :tax_rate_category = STD | total = 7.04 
:break_type = 1, :state = ON, :tax_type = HST, :tax_rate_category = STD | total = 11.27 
:break_type = 1 | total = 1.41 
:break_type = 2 | total = 17.30 

我有叫@amounts數組這些哈希值。

我有像merge!,inject,shift和更多的方法，通過我的頭，但不能把它放在一起。

Answer 1

這個怎麼樣？不過，我真的不知道你在那裏做什麼。

@amounts = [ 
#First order - has charges for Canadian GST and HST 
{:orderhdr_id=>17654122, :order_item_seq=>1, :order_item_amt_break_seq=>1, :order_item_break_type=>0, :local_amount=>8.16, :base_amount=>8.16, :orig_base_amount=>149, :tax_delivery=>0, :tax_active=>0}, 
{:orderhdr_id=>17654122, :order_item_seq=>1, :order_item_amt_break_seq=>2, :order_item_break_type=>1, :local_amount=>0.41, :base_amount=>0.41, :state=>"ON", :tax_type=>"GST", :tax_rate_category=>"STD", :orig_base_amount=>7.45, :tax_rate=>5, :tax_delivery=>0, :tax_active=>1, :tx_incl=>1}, 
{:orderhdr_id=>17654122, :order_item_seq=>1, :order_item_amt_break_seq=>3, :order_item_break_type=>1, :local_amount=>0.65, :base_amount=>0.65, :state=>"ON", :tax_type=>"HST", :tax_rate_category=>"STD", :orig_base_amount=>11.92, :tax_rate=>8, :tax_delivery=>0, :tax_active=>1, :tx_incl=>1}, 
#Second order - has only one charge for tax 
{:orderhdr_id=>1815296, :order_item_seq=>1, :order_item_amt_break_seq=>1, :order_item_break_type=>0, :local_amount=>76.52, :base_amount=>76.52, :orig_base_amount=>99.95, :tax_delivery=>0, :tax_active=>0}, 
{:orderhdr_id=>1815296, :order_item_seq=>1, :order_item_amt_break_seq=>2, :order_item_break_type=>1, :local_amount=>4.59, :base_amount=>4.59, :orig_base_amount=>6, :tax_delivery=>0, :tax_active=>1}, 
#Third order - has charge for shipping 
{:orderhdr_id=>6112412, :order_item_seq=>1, :order_item_amt_break_seq=>1, :order_item_break_type=>0, :local_amount=>21.34, :base_amount=>21.34, :orig_base_amount=>99.95, :tax_delivery=>0, :tax_active=>0}, 
{:orderhdr_id=>6112412, :order_item_seq=>1, :order_item_amt_break_seq=>2, :order_item_break_type=>2, :local_amount=>4.7, :base_amount=>4.7, :orig_base_amount=>22, :tax_delivery=>0, :tax_active=>0}, 
] 

@totals = Hash.new(0) 

@amounts.group_by{|row| row[:order_item_break_type]}.each do |break_type, rows| 

    rows.each do |row| 

    key = [break_type, row[:tax_type]] 
    @totals[key] += row[:orig_base_amount] - row[:base_amount] 

    end 
end 

@totals 
# => {[0, nil]=>242.88, 
#  [1, "GST"]=>7.04, 
#  [1, "HST"]=>11.27, 
#  [1, nil]=>1.4100000000000001, 
#  [2, nil]=>17.3}