Ruby on rails Rails：尝试保存现有行，但Rails生成sql insert而不是update 错误

当我有一张新唱片时，我没有问题

当我有一个正在尝试更新的现有记录时，会抛出一个异常（见下文）

以下两种Rails代码变体在我希望更新的email_addresses表中有一行时都会引发相同的异常：

ret = @email_address.update(email_address_id: @email_address.email_address_id)

我也试过了

ret = @email_address.save

并得到相同的异常

例外 当我有一个想要更新的现有记录时，我得到的错误是

#<ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "email_addresses_pkey"
DETAIL:  Key (email_address_id)=(2651) already exists.
: INSERT INTO "email_addresses" ("email_address_id", "email_address", "zipcode", "confirm_token") VALUES ($1, $2, $3, $4) RETURNING "email_address_id">

模型 如果email\u address\u id已经存在于email\u addresses表中，由于

"email_addresses_pkey" PRIMARY KEY, btree (email_address_id)

主键上的隐式约束

我可能可以通过直接在Rails中编写SQL代码来实现这一点，但我希望继续使用Rails代码并理解我做错了什么

我在网上搜索了好几个小时都没有成功。我曾尝试过跟踪rails代码，但由于元编程代码太复杂，我迷路了

问题 Rails如何知道何时进行SQL更新而不是SQL插入

---

鉴于我现有的电子邮件地址表，如何更新现有记录？

由于您使用的是非标准id，您需要告诉rails要将该列用作主键，这样它可以评估是否应该插入或更新保存

为此，您需要在模型中添加

self.primary\u key='email\u address\u id'

记住Rails更喜欢约定而不是配置，所以任何时候打破约定都需要告诉Rails

---

注意：将

电子邮件地址的pkey命名为
电子邮件地址id
，似乎是多余的；通常，FKEY通常使用
resource\u id
的格式，而对于PKEY，您可以定义列名。
谢谢您的回答，但这似乎不是我的问题。这个问题似乎与持久化有关？功能。我会补充更多，因为我知道的更多。我想知道为什么这被否决了，这样我可以在将来改进我的问题。
class EmailAddress < ApplicationRecord
  validates_presence_of :email_address
  validates_format_of :email_address, with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, on: :create
  validates_format_of :email_address, with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, on: :save
  validates_format_of :email_address, with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, on: :update

  def initialize(email_address_params)
    super(email_address_params)
    confirmation_token()
  end


  # zipcodes can be nil/null in the database but we should never allow a human user to create such a record.
  validates_presence_of :zipcode
  validates_format_of :zipcode, with: /\A\d{5}(-\d{4})?\z/, message: "zipcode should be in the form 12345", on: :create

  def email_activate
    self.email_confirmed = true
    self.confirm_token = nil
    save!(:validate => false)
  end

  private
  def confirmation_token
    if self.confirm_token.blank?
      self.confirm_token = SecureRandom.urlsafe_base64.to_s
    end
  end
end

INSERT INTO "email_addresses" ("email_address_id", "email_address", "zipcode", "confirm_token") VALUES ($1, $2, $3, $4) RETURNING "email_address_id"  [["email_address_id", 2651], ["email_address", "ralphs@dos32.com"], ["zipcode", "80503"], ["confirm_token", "r-UX4zOdOmHC7lO7Ta2pBg"]]

"email_addresses_pkey" PRIMARY KEY, btree (email_address_id)