轨道中的多个DB连接

Question

I am trying to connect multiple database in ROR application.My database.yml is look like this in your database.yml file

development:

 adapter: mysql
 username: root
 password: 
 database: example_development

private:

adapter: mysql
username: root
password: 
database: example_private_development

It is possible to connect using establish_connection :private

My doubt is that how use rake db:create.I am not able get solution from google.

Please help me to clear it.

Answer 1

Try

rake db:create:all

And yes, it's possible to have multiple db connections in a Rails application.

This is what I did once, I have created two classes which inherit from ActiveRecord::Base and set the connections inside those classes.

Then I inherited all my models in one of those classes instead of direct ActiveRecord

Below is an example:

database.yml file

#app uses two database
#1 - test1
#2 - test2
test1:
  adapter: mysql
  encoding: utf8
  database: test1
  username: root 
  password: xxx
  host: localhost

test2:
  adapter: mysql
  encoding: utf8
  database: test2
  username: root
  password: xxx
  host: localhost

Then I have two models for both test1 and test2 databases:

class Test1Base < ActiveRecord::Base
    self.abstract_class = true
    establish_connection("test1")
end

class Test2Base < ActiveRecord::Base
  # No corresponding table in the DB.
  self.abstract_class = true
  establish_connection("test2")
end

Then I inherit my models according to database:

class School < Test1Base
  #code
end

class Student < Test2Base
  #code
end

Answer 2

Thanks for reply.

we can migrate a model for particular DB, for example

db:migrate RAILS_ENV="portal_development"' .

And more change for establishing connection with DB.check the corrected below

class Test1Base < ActiveRecord::Base
  self.abstract_class = true
  establish_connection :development
end

class Test2Base < ActiveRecord::Base
  # No corresponding table in the DB.
  self.abstract_class = true
  establish_connection :portal_development
end

Thanks sameera for your valuable reply.

cheers

Shamith c

Answer 3

Possibly use active_delegate ? http://railslodge.com/plugins/595-active-delegate