Connecting to 2 databases during unit testing results in error

Question

I've started a form that submits to a PostgresSQL database and I've done numerous tests on my models to verify my validation. However, I created a custom validator which checks a legacy Oracle database to verify that a license number provided in a form by an end-user exists in the legacy database. Via the command line debugger, I can verify that the library I created connects to the database and returns results and that the custom validator causes the model to be invalid if the criteria isn't met. However, when I run my unit tests against my model, an error occurs when the tests run. If I remove the custom validation, the tests run pass.

PG::Error: ERROR:  relation "LICENSE" does not exist
      LINE 4:              WHERE a.attrelid = '"LICENSE"'::regclass
                                              ^
      :             SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
                    FROM pg_attribute a LEFT JOIN pg_attrdef d
                      ON a.attrelid = d.adrelid AND a.attnum = d.adnum
                   WHERE a.attrelid = '"LICENSE"'::regclass
                     AND a.attnum > 0 AND NOT a.attisdropped
                   ORDER BY a.attnum

From what I see, it appears as though the tests are trying to run the custom validation against the PostgresSQL database specified in the database.yml file instead of the Oracle database that is specified in the library I wrote. I'm not quite sure if this is the cause or if it is why it is occurring and how I can resolve the issue.

Here is what my library file looks like:

module Legacy
  DB_CONFIG = YAML::load(File.open("#{Rails.root}/config/legacy_database.yml"))[Rails.env]

  class Legacy::License < ActiveRecord::Base
    establish_connection DB_CONFIG

    self.table_name = "LICENSE"
    self.primary_key = "LICENSE_ID"
  end
end

This is my model:

require "#{Rails.root}/lib/legacy.rb"

class Vehicle < ActiveRecord::Base
  belongs_to :user

  validates_presence_of :permit_license, :name
  validate :validate_license

  def validate_license
    license = Legacy::License.where('license_number = ?', license_number)

    if license.empty?
      errors.add(:license_number, 'License not valid')
    end
  end
end

Any insight into why this is occurring would be helpful and appreciated.

Answer 1

I think it's the way you've configured the two databases. I have a similar situation, a Legacy database mixed with a Rails ActiveRecord based database. (SQLServer & mysql in my case)

Here is how I configure it. (development only shown):

config/database.yml:

aimdevelopment:
  adapter: sqlserver
  .... 

development: 
  adapter: mysql2
  .....

My Legacy system is called AIM

Then I create a base model for ALL my Legacy Models to follow:

models/aim.rb:

class Aim < ActiveRecord::Base
  establish_connection ("aim#{Rails.env}")
end

Then if I need to connect to table in the legacy database

class Product < AIM
  self.table_name 'Product'
  self.primary_key 'ProductID'
end

I Think the fact that you've circumvented rails when you tried to manage the 'establish_connection' within your module may be what is screwing you up.