在 Rails/ActiveReocrd 中有一种方法可以用另一个实例替换一个实例,以便解决所有关系/外键。
我可以想象这样的事情:
//setup
customer1 = Customer.find(1)
customer2 = Customer.find(2)
//this would be cool
customer1.replace_with(customer2)
假设 customer1 配置不当,有人创建了 customer2,但不知道 customer1,能够快速将所有内容设置为 customer2 就好了
因此,这也需要更新任何外键
用户所属:客户
网站所属:客户
然后任何具有外键 customer_id = 1 的用户/网站将通过此 'replace_with' 方法自动设置为 2
这样的事情存在吗?
[我可以想象一个涉及 Customer.reflect_on_all_associations(:has_many) 等的黑客攻击]
干杯,
J
最佳答案
像这样的事情可以工作,尽管可能有更合适的方法:
更新 :更正了关联示例中的一些错误。
class MyModel < ActiveRecord::Base
...
# if needed, force logout / expire session in controller beforehand.
def replace_with (another_record)
# handles attributes and belongs_to associations
attribute_hash = another_record.attributes
attribute_hash.delete('id')
self.update_attributes!(attribute_hash)
### Begin association example, not complete.
# generic way of finding model constants
find_model_proc = Proc.new{ |x| x.to_s.singularize.camelize.constantize }
model_constant = find_model_proc.call(self.class.name)
# handle :has_one, :has_many associations
have_ones = model_constant.reflect_on_all_associations(:has_one).find_all{|i| !i.options.include?(:through)}
have_manys = model_constant.reflect_on_all_associations(:has_many).find_all{|i| !i.options.include?(:through)}
update_assoc_proc = Proc.new do |assoc, associated_record, id|
primary_key = assoc.primary_key_name.to_sym
attribs = associated_record.attributes
attribs[primary_key] = self.id
associated_record.update_attributes!(attribs)
end
have_ones.each do |assoc|
associated_record = self.send(assoc.name)
unless associated_record.nil?
update_assoc_proc.call(assoc, associated_record, self.id)
end
end
have_manys.each do |assoc|
associated_records = self.send(assoc.name)
associated_records.each do |associated_record|
update_assoc_proc.call(assoc, associated_record, self.id)
end
end
### End association example, not complete.
# and if desired..
# do not call :destroy if you have any associations set with :dependents => :destroy
another_record.destroy
end
...
end
我已经包含了一个关于如何处理某些关联的示例,但总的来说这可能会变得棘手。
关于ruby-on-rails - 重新分配 ActiveRecord 实例和相应的外键,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7507878/