当我从表单发布POST时，我无法弄清楚为什么我的数据库记录没有得到更新，或者创建了新记录。
我能够手动填充数据库并创建关系：
contact = Contact.first
command = Command.find(3)
contact.host_notification_commands << command
我也可以在表单中加载此数据信息。我无法弄清楚的是如何更新或添加新记录。到目前为止我尝试过的所有东西都失败了。
我有3个模型 - Command，Contact和加入CommandsContact。 commands_contacts联接表正在支持一个额外的属性:notification_type，该属性可以设置为主机或服务，以及我的Contact模型设置了2个额外的关系，我可以访问:host_notification_commands和:service_notification_commands。这使我能够执行Contact.fist.host_notification_commands或Contact.find(3).service_notification_commands.
似乎没有UPDATE或INSERT查询从控制器启动，当我正确POST时，我无法弄清楚如何调试它。
模型
class Command < ActiveRecord::Base
has_many :commands_contacts
has_many :contacts, :through => :commands_contacts
end
class Contact < ActiveRecord::Base
has_many :commands_contacts
has_many :commands, :through => :commands_contacts
has_many :host_notification_commands, -> { where commands_contacts: { :notification_type => 'host' } },
:through => :commands_contacts,
:class_name => 'Command',
:source => :command
has_many :service_notification_commands, -> { where commands_contacts: { notification_type: 'service' } },
:through => :commands_contacts,
:class_name => 'Command',
:source => :command
accepts_nested_attributes_for :commands, :host_notification_commands, :service_notification_commands
end
class CommandsContact < ActiveRecord::Base
belongs_to :command
belongs_to :contact
accepts_nested_attributes_for :command
end
此后一切都崩溃了。
控制器
由于我使用的是accepts_nested_attributes_for，我必须将_attributes附加到我的嵌套对象的名称 - :host_notification_commands和:service_notification_commands。我将改变我的表单以这种方式提交，但简单的重新分配工作是为了一个例子。
def update
contact = Contact.find_by_id(params[:id])
contact.update(safe_params)
end
private
def safe_params
params[:contact][:host_notification_commands_attributes] = params[:contact][:host_notification_commands]
params[:contact][:service_notification_commands_attributes] = params[:contact][:service_notification_commands]
params.require(:contact)
.permit(:contact_name, :host_notification_commands_attributes => [:id, :command_name, :command_line, :command_description],
:service_notification_commands_attributes => [:id, :command_name, :command_line, :command_description])
end
更新现有记录结果：
#<ActiveRecord::RecordNotFound: Couldn't find Command with ID=2 for Contact with ID=1>
当然它不存在！我正在努力建立这种关系！
添加一个新的，我得到：
#<ActiveRecord::RecordNotFound: Couldn't find Command with ID=1 for Contact with ID=>
绝对正确。用户甚至还没有创建，并且没有与命令建立关系，为什么Rails试图找到它？
我也没有看到在rails控制台中记录任何更新或插入查询，所以我想它甚至没有达到那一点......
D, [2015-01-20T18:01:30.336669 #95542] DEBUG -- : (0.1ms) BEGIN
D, [2015-01-20T18:01:30.338971 #95542] DEBUG -- : Command Load (0.3ms) SELECT `commands`.* FROM `commands` INNER JOIN `commands_contacts` ON `commands`.`id` = `commands_contacts`.`command_id` WHERE `commands_contacts`.`contact_id` = 1 AND `commands_contacts`.`notification_type` = 'host' AND `commands`.`id` IN (1, 3)
D, [2015-01-20T18:01:30.340555 #95542] DEBUG -- : Command Load (0.2ms) SELECT `commands`.* FROM `commands` INNER JOIN `commands_contacts` ON `commands`.`id` = `commands_contacts`.`command_id` WHERE `commands_contacts`.`contact_id` = 1 AND `commands_contacts`.`notification_type` = 'service' AND `commands`.`id` IN (4, 2)
D, [2015-01-20T18:01:30.341501 #95542] DEBUG -- : (0.1ms) ROLLBACK
#<ActiveRecord::RecordNotFound: Couldn't find Command with ID=2 for Contact with ID=1>
Completed 200 OK in 11ms (Views: 0.4ms | ActiveRecord: 0.9ms)
我在这里错过了什么？
编辑：我想我可以放弃使用strong_parameters的想法，解析所有POST参数，然后手动填充数据库，但那不是很Rails-y。
编辑＃2：包括发布到控制器的参数。
来自表格
的params[:contact]数据
{
"contact_name" => "joe-user",
"host_notification_commands" => [
[0] {
"id" => 1,
"command_name" => "host-notify-by-email",
"command_line" => "/usr/local/bin/host-notify",
"command_description" => "Host Alert",
"created_at" => "2015-01-19T17:24:12.000Z",
"updated_at" => "2015-01-21T03:29:03.000Z"
},
[1] {
"id" => 2,
"command_name" => "host-notify-by-pager",
"command_line" => "/usr/local/bin/host-notify-pager",
"command_description" => "Host Alert by Pager",
"created_at" => "2015-01-19T17:24:33.000Z",
"updated_at" => "2015-01-19T17:24:33.000Z"
}
],
"service_notification_commands" => [
[0] {
"id" => 4,
"command_name" => "service-notify-by-email",
"command_line" => "/usr/local/bin/service-notify",
"command_description" => "Service Alert",
"created_at" => "2015-01-19T17:24:44.000Z",
"updated_at" => "2015-01-19T17:24:44.000Z"
}
]
}
经过strong_parameters之后就变成了这个：
基本上是同一件事，只有created_at和updated_at被剥离和
_attributes附加到属性名称，因此它适用于accept_nested_attributes_for
{
"contact_name" => "joe-user",
"host_notification_commands_attributes" => [
[0] {
"id" => 1,
"command_name" => "host-notify-by-email",
"command_line" => "/usr/local/bin/host-notify",
"command_description" => "Host Alert"
},
[1] {
"id" => 2,
"command_name" => "host-notify-by-pager",
"command_line" => "/usr/local/bin/host-notify-pager",
"command_description" => "Host Alert by Pager"
}
],
"service_notification_commands_attributes" => [
[0] {
"id" => 4,
"command_name" => "service-notify-by-email",
"command_line" => "/usr/local/bin/service-notify",
"command_description" => "Service Alert"
}
]
}
编辑＃3：我启用了MySQL查询日志记录，但我根本没有看到UPDATE / INSERT个查询。我如何调试为什么contact.update(safe_params)没有做任何事情？
编辑＃4：作为一个没有AngularJS或POST的简单测试，我做了一个简单的rake任务，定义了一个JSON对象并尝试更新数据库。我得到了同样的问题，所以我很确信这个问题出现在我的模型中......但是在哪里???
请看一下这个要点https://gist.github.com/pruchai/6afe74b170da2a3d307f
答案 0 :(得分：2)
构建表单并使用nested_fields_for时，您的表单结构已正确构建。因此，理想情况下，您首先尝试“老式的方式”，检查推送到服务器的内容并模仿它。
所以一般情况下我不是手工完成这个，但是我维护一个gem来处理嵌套表单（cocoon），所以如果我没有弄错，要使accepts_nested_attributes起作用，参数必须如下所示：
{
"contact_name" => "joe-user",
"host_notification_commands_attributes" => {
"0" => {
"id" => 1,
"command_name" => "host-notify-by-email",
"command_line" => "/usr/local/bin/host-notify",
"command_description" => "Host Alert"
},
"1" => {
"id" => 2,
"command_name" => "host-notify-by-pager",
"command_line" => "/usr/local/bin/host-notify-pager",
"command_description" => "Host Alert by Pager"
}
},
"service_notification_commands_attributes" => {
"0" => {
"id" => 4,
"command_name" => "service-notify-by-email",
"command_line" => "/usr/local/bin/service-notify",
"command_description" => "Service Alert"
},
"12342233444444" => {
"command_name" => "service-notify-by-email",
"command_line" => "/usr/local/bin/service-notify",
"command_description" => "Service Alert"
}
}
}
因此.._attributes应该包含一个哈希，而不是一个数组。关键是（现有）数组中的位置，我asuume。在cocoon中，我用这个虚拟索引填充一些从当前时间派生的大数字。我假设这个顺序应该对应于关系的默认顺序。但是如果你把“id”字段放下来，那么rails也可以使用它。不确定。要销毁现有元素，您必须设置_destroy属性（并在强参数中允许它）。
对于新项目的Imho id应为空，否则rails将假定该项存在（因为通常不会在客户端生成ID）。