我已经打破了近两天的头，我找不到解决方案。
我有一张表格，列出发票编号、总额、已付金额和余额；它运作良好。现在我必须将所有行项目添加到表中。
invoices 表有以下列：of_lax、air_rate_customer、pss，所以这部分很简单，我只需要检查那里是否有值。
棘手的部分是fcl_variable_cost_1_amount属性，我得到了其中的 8 个（fcl_variable_cost_1_amount、fcl_variable_cost_2_amount 等）。
有一个对应的fcl_variable_cost_1_amountfcl_variable_cost_1_charge_id 链接到一个 Charge 表。
因此，在一张发票中，fcl_variable_cost_1_id 可能为 34，金额为 100 美元（id 34 对应于“ISF”）。
在另一张发票中，fcl_variable_cost_1_id 可能是 12，金额为 50 美元（id 12 对应于“考试费”）。
那么如何使变量名称行项目出现在它们应该出现的列中？
这是我的代码。还有一个截图。
<% headings = Hash.new %>
<% @shipments.each do |shipment| %>
<% unless shipment.invoice.nil? %>
<% unless shipment.invoice.of_customer_amount_for_customer_inv.nil? %>
<% headings['of_customer_amount_for_customer_inv'] = "Ocean Freight (FCL)" %>
<% end %>
<% unless shipment.invoice.of_lax.nil? %>
<% headings['of_lax'] = "Ocean Freight (LCL)" %>
<% end %>
<% unless shipment.invoice.air_rate_customer.nil? %>
<% headings['air_rate_customer'] = "Air Freight" %>
<% end %>
<% unless shipment.invoice.pss.nil? %>
<% headings['pss'] = "PSS" %>
<% end %>
<% unless shipment.invoice.hc_lax.nil? %>
<% headings['hc_lax'] = "HC LAX" %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_1_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_1_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_1_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_2_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_2_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_2_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_3_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_3_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_3_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_4_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_4_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_4_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_5_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_5_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_5_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_6_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_6_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_6_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_7_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_7_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_7_charge_id).name %>
<% end %>
<% unless shipment.invoice.fcl_variable_cost_8_amount.nil? %>
<% headings[(Charge.find(shipment.invoice.fcl_variable_cost_8_charge_id)).name] = Charge.find(shipment.invoice.fcl_variable_cost_8_charge_id).name %>
<% end %>
<% end %>
<% end %>
<table>
<tr>
<th colspan="9">Customer AR Statement for <%= @customer.company_name %></th>
</tr>
<tr>
<th style="text-align:center;">MTY</th>
<th>Shipper</th>
<th>HBL</th>
<th>Container</th>
<th>Status</th>
<th>Age</th>
<th>Delivered Customer</th>
<th>Invoice Date</th>
<% headings.each_pair do |k,v|%>
<th><%= v %></th>
<% end %>
<th>Invoice Total</th>
<th>Amount Paid</th>
<th>Balance</th>
</tr>
<% @shipments.each do |shipment| %>
<tr>
<td style="text-align:center;"><%= shipment.file_number %></td>
<td><%= shipment.shipper.company_name %></td>
<td><%= shipment.hbl %></td>
<td><%= shipment.container %></td>
<td><%= shipment.status %></td>
<td><%= shipment.age %></td>
<td><%= shipment.invoice.delivered_customer ? "Yes" : "No" %></td>
<td><%= shipment.invoice.read_issued_at unless shipment.invoice.nil? %></td>
<% if shipment.invoice.nil? %>
<td colspan="<%= headings.count %>"></td>
<% else %>
<% headings.each_pair do |k,v| %>
<% if k == "of_lax" and !shipment.invoice.of_lax.nil? %>
<td><%= number_to_currency shipment.invoice.lcl_of_customer_total %>
<% elsif k == "of_customer_amount_for_customer_inv" and !shipment.invoice.of_customer_amount_for_customer_inv.nil? %>
<td><%= number_to_currency shipment.invoice.of_customer_amount_for_customer_inv %></td>
<% elsif k == "air_rate_customer" and !shipment.invoice.air_rate_customer.nil? %>
<td><%= number_to_currency (shipment.volweight * shipment.invoice.air_rate_customer.to_s.to_d) %></td>
<% elsif k == "pss" and !shipment.invoice.pss.nil? %>
<td><%= number_to_currency (shipment.invoice.pss.to_s.to_d * shipment.volweight) %></td>
<% elsif k == "hc_lax" and !shipment.invoice.hc_lax.nil? %>
<td><%= number_to_currency (shipment.invoice.hc_lax.to_s.to_d * shipment.volweight) %></td>
<% else %>
<td></td>
<% end %>
<% end %>
<% end %>
<td style="text-align:right;"><%= number_to_currency shipment.invoice.customer_total unless shipment.invoice.nil? %></td>
<td style="text-align:right;"><%= number_to_currency shipment.invoice.customer_amount_paid unless shipment.invoice.nil? %></td>
<td style="text-align:right;"><%= number_to_currency shipment.invoice.customer_open_balance unless shipment.invoice.nil? %></td>
</tr>
<% end %>
<tr>
<td colspan="<%= 7 + (headings.count) %>"></td>
<th>Totals</th>
<td style="text-align:right;"><%= number_to_currency @totals[:overall] %></td>
<td style="text-align:right;"><%= number_to_currency @totals[:paid] %></td>
<td style="text-align:right;"><%= number_to_currency @totals[:balance] %></td>
</tr>
</table>