与活动记录交叉数据库连接

Question

I have two websites that each connect to their own unique databases. I need to validate in website 'A' that an email address exists in the website 'B' database. I'm doing the validation as follows:

Called from website 'A's AccountController < ApplicationController class:

config = YAML::load(File.open("#{RAILS_ROOT}/config/database.yml"))
      ActiveRecord::Base.establish_connection(config["database B"])
      if ActiveRecord::Base.connection.select_values("SELECT "database B".X
          FROM 'database B".X WHERE 'database B'.X.email = @member_email")

This call works when I test it in my development and QA environments but fails in my production environment. What appears to happen in production is that the value of the ActiveRecord and also the select get's co-mingled with currently logged-in user's active records, but only in production.

Okay so I've modified my files to the following, based on the feedback. Still not working... Could someone please review the files below and see what step(s) I'm missing? Thanks!

Thanks! I think that is what I did, but I created the 'model', and, being a newbie, I'm not sure if that would normally be generated by Rails...

Still failing, would you mind taking a look at the following and see if you see what I'm doing wrong?

First, this is the 'legacy' database model for the second database that I want to connect to in the existing application (Note that doing the 'Fileload' was the only way I could get this to not error out.):

class MMSDB < ActiveRecord::Base

self.abstract_class = true #important!

config = YAML::load(File.open("#{RAILS_ROOT}/config/database.yml"))

establish_connection(config["deals_qa"])

end

Second, this is the model that calls the 'MMSDB' Model (see above)

class Redirect < MMSDB

def initialize

end

Checking to see if the email address exists in the legacy database, and, if it does, the #increment the redirect count on the # database table 'members'

Do I somehow need to tell the application what table I want to pull from since the table # in the legacy database (members) would be different then in the current application #database (users)

def email_exists?(email) if find_by_email(email) user = find_by_email(email) user.redirect_count += 1 user.save end end

end

Then this is the code snippet inside the account controller file.

        else
        if user == Redirect::User.email_exists?(@email)
            @Redirect_Flag = true
        else
            flash.now[:error] = 'Invalid email or password; please try again.'
        end
     end

Answer 1

Subclassing ActiveRecord::Base will allow you to make multiple connections to different databases.

module DatabaseB
  class Base < ActiveRecord::Base
    @abstract_class = true
    establish_connection(config["database B"])
  end
end

class YourAwesomeModel < DatabaseB::Base
  set_table_name "X"
  # Use your regular active record magic
end

You will still be able to use your other models with the connection established using ActiveRecord::Base to your primary database.