1
我做了一个应用程序使用轨道,我有问题做每一行的总和,但我得到的错误。如何求和数组中的值?
这里我的表:
|policies|
|id| |num_policy|
1 1000
2 1001
3 1002
4 1003
|policy_vehicles|
|id| |policy_id| |vehicle_id|
1 1 1
2 1 2
3 2 1
4 2 3
5 3 1
6 4 4
7 4 2
|vehicles|
|id| |name| |amount|
1 VEHICLE1 8000
2 VEHICLE2 8001
3 VEHICLE3 8002
4 VEHICLE4 8003
这是我的控制器: “应用程序/控制器/ policy_controller.rb”
型号:
class PolicyVehicle < ActiveRecord::Base
belongs_to :vehicle
belongs_to :policy
end
class Vehicle < ActiveRecord::Base
belongs_to :policy
has_many :policy_vehicles
end
class Vehicle < ActiveRecord::Base
has_many :policy_vehicles
end
这是我的索引的观点:“应用/views/policy/index.html.erb“
<table border="1">
<tr>
<td>POLICY ID</td>
<td>NUM POLICY</td>
</tr>
<% @policies.each do |policy| %>
<tr>
<td><%= policy.id %></td>
<td><%= policy.num_policy %></td>
</tr>
<% policy.policy_vehicles.each do |policy_vehicle| %>
<tr>
<td></td>
<td><%= policy_vehicle.vehicle.name %></td>
<td><%= policy_vehicle.vehicle.amount %></td>
</tr>
<% end %>
<tr>
<td></td>
<td>TOTAL</td>
<td><%= policy.policy_vehicles.vehicles.sum(:amount) %></td>
</tr>
<% end %>
</table>
如果我尝试:
<%= policy.policy_vehicles.vehicles.sum(:amount) %>
##### GET THIS ERROR #####
undefined method `vehicles' for #<Class:0x7ff4293ac3f0>
如果我尝试:
<%= policy.policy_vehicles.vehicle.sum(:amount) %>
##### GET THIS ERROR #####
undefined method `vehicle' for #<Class:0x7ff42ae95a90>
如果我尝试:
<%= policy.policy_vehicles.vehicles.collect(&:amount).sum %>
##### GET THIS ERROR #####
undefined method `vehicles' for #<Class:0x7ff429337410>
如果我尝试:
<% policy.policy_vehicles.each do |policy_vehicle|%>
<%= policy_vehicle.vehicle.sum(:amount)
<% end %>
##### GET THIS ERROR #####
undefined method `sum' for #<ActiveRecord::Associations::BelongsToAssociation:0x7ff4295dbd60>
最后我想:
<% policy.policy_vehicles.each do |policy_vehicle|%>
<%= policy_vehicle.vehicle.amount.sum
<% end %>
##### GET THIS ERROR #####
undefined method `sum' for 8000:Fixnum
我想做这个例子:
请有人可以帮助我吗?
出了什么问题?
所有类型的帮助将被接受。
奇+1的出色答卷,这也我写了良好的细节和问题很好解释的通知:d – 2014-09-23 16:00:51