ruby-on-rails – 为什么before_save不会被调用ActiveRecord模型

当我使用IRB创建一个新的模型实例并保存时,没有什么打印到控制台,我得到一个“ActiveRecord :: StatementInvalid：Mysql :: Error：Column’user_id’不能为空”的错误,所以我假设before_save不是被叫我不知道为什么.我甚至尝试使用before_save过滤器.这是我的代码：

require 'secure_resource/secure_resource_encryption'

class Database < ActiveRecord::Base
  belongs_to :username_encryption,:class_name => "Encryption",:foreign_key => :username_encryption_id
  belongs_to :password_encryption,:foreign_key => :password_encryption_id

  # Virtual attribute to retrieve the decrypted username.
  def username
    if self.username_encryption.nil?
      return nil
    end

    begin
      return self.username_encryption.encryption
    rescue SecureResourceError
      raise SecureResourceError
    end
  end

  # Provides a way to reset the username.
  def username=(username)
    if self.username_encryption.nil?
      self.username_encryption = Encryption.new
      self.username_encryption.encryption = username
    end
  end

  # Virtual attribute to retrieve the decrypted password.
  def password
    if password_encryption.nil?
      return nil
    end

    begin
      return password_encryption.encryption
    rescue SecureResourceError
      raise SecureResourceError
    end
  end

  # Provides a way to reset the password.
  def password=(password)
    if self.password_encryption.nil?
      self.password_encryption = Encryption.new
      self.password_encryption.encryption = password
    end
  end

  def before_save
    p 'ZZZZZZZZZZZZZZZ'
    p self.user_id.to_s + ' ZZZZZZ'
    p 'ZZZZZZZZZZZZZZZ'
    self.username_encryption.user_id = self.user_id
    self.username_encryption.save
    self.username_encryption_id = self.username_encryption.id

    self.password_encryption.user_id = self.user_id
    self.password_encryption.save
    self.password_encryption_id = self.password_encryption.id
  end
end