Question

如何在模型被销毁之前调用模型中编写方法？

例如，当Model A为destroyed

时，我想写一个循环来更新另一个

String insertText = "INSERT INTO alpha_screen (alpha, screen) VALUES (?,?)";
PreparedStatement preparedStatement = InsertWordCount.PrepareText(insertText);
BoundStatement boundStatement = preparedStatement.bind(keyvalue, newword);  //INSERT positions
getSession().execute(boundStatement);

cqlsh> SELECT * FROM rant.alpha_screen; ==> The INSERTS are done as expected.

alpha  | screen
-------+--------------
a      |   ['aboard']
c      | ['checking']
p      |     ['pull']
r      |  ['rotting']
t      |     ['time']

中的一堆内容

Answer 1

回调是什么，在您的情况下，您可以使用before_destroy回调，例如：

class ModelA
before_destroy :do_bunch_of_things

def do_bunch_of_things
...
end
end

Answer 2

当一个对象被销毁时，Active Record有三个可用的回调：before_destroy，around_destroy和after_destroy。一个例子：

class Article < ActiveRecord::Base
  after_destroy :log_destroy_action

  def log_destroy_action
    puts 'Article destroyed'
  end
end

此处提供更多信息：http://guides.rubyonrails.org/active_record_callbacks.html

rails模型做了一些破坏

2 个答案: