How to consolidate these many rake tasks into one task - ruby-on-rails

Question

The application I'm working on runs import tasks each night to get information from an external database and processes and writes it to the local PostgreSQL database. This is so it can be viewed in our application.
We do the following:
Create a connection to the external database
Perform some currency conversion
Do some calculations on the data based on the average
Check if the item already exists and update if it's changed
Also check to see how it is classified and change the category to fit our categorisations
Create the item if it does not exist
All of this data is on different tables in the external database, so I've created a task for each table (about 30), but I am repeating myself excessively so looking for some guidance on how to DRY this bad boy up.
Is it possible to create some kind of loop on a collection of the external database table names? I've tried this a couple of times but haven't had any success. Please find the code below of examples of two different import scripts.
desc 'Imports ABC Data'
task :abcdeal_import => :environment do
# Connect to legacy db
class OldDb < ActiveRecord::Base
establish_connection :cleardb
self.table_name = 'abcdeal'
end
class Import < OldDb
self.table_name = 'abcdeal'
end
# Currency Conversion
require 'money'
require 'money/bank/google_currency'
# set the seconds after than the current rates are automatically expired
Money::Bank::GoogleCurrency.ttl_in_seconds = 86400
# set default bank to instance of GoogleCurrency
bank = Money::Bank::GoogleCurrency.new
#gbp = bank.get_rate(:USD, :GBP).to_f
#eur = bank.get_rate(:USD, :EUR).to_f
#aud = bank.get_rate(:USD, :AUD).to_f
#cad = bank.get_rate(:USD, :CAD).to_f
#nzd = bank.get_rate(:USD, :NZD).to_f
Import.all.find_each do |u|
# Define Variables
#price = u.UnitPrice
#interest = u.UnitSold
##interest_changes = u.unitsold_changes
#company = u.Company
#legacy_id = u.id
#end_date = u.EndDate
#category = u.Category
#revenue = u.Revenue
# Calculate average
#company_average = company_average(#company)
if #company_average == 0
#company_average = 1
end
# Does item exist?
if Dailydeal.exists?(:legacy_id => #legacy_id, :company => #company)
# It exists.
#historical_interest = Product.where(:legacy_id => #legacy_id).pluck(:interest)
# Another statement to check that the Interest != UnitSold
if #interest != #historical_interest
Product.where(:legacy_id => #legacy_id, :company => #company).update_all(:interest => #interest, :end_date => #end_date, :interest_changes => #interest_changes, :status => average_change_interest, :revenue => #revenue, :revenue_eur => eur_revenue_currency_conversion, :revenue_aud => aud_revenue_currency_conversion, :revenue_gbp => gbp_revenue_currency_conversion, :revenue_cad => cad_revenue_currency_conversion, :revenue_nzd => nzd_revenue_currency_conversion)
end
else
# Doesn't exist
# Set Category
case #category
when 'Apparel'
#category = 'Apparel & Footwear'
when 'Gadgets'
#category = 'Electronics & Accessories'
when 'Gifts'
#category = 'Miscellaneous'
when 'Health & Cosmetics'
#category = 'Health & Beauty'
when 'Home'
#category = 'Home & Furniture'
when 'Other'
#category = 'Miscellaneous'
when 'Toys'
#category = 'Toys & Kids'
else
#category
end
Product.create(
:name => u.ProductName,
:link => u.ProductLink,
:image_url => u.ImageUrl,
:price => u.UnitPrice,
:interest => u.UnitSold,
:start_date => u.StartDate,
:end_date => u.EndDate,
:revenue => u.Revenue,
:company => u.Company,
:category => #category,
:country => u.Country,
:price_eur => eur_currency_conversion,
:price_aud => aud_currency_conversion,
:price_gbp => gbp_currency_conversion,
:price_cad => cad_currency_conversion,
:price_nzd => nzd_currency_conversion,
:revenue_eur => eur_revenue_currency_conversion,
:revenue_aud => aud_revenue_currency_conversion,
:revenue_gbp => gbp_revenue_currency_conversion,
:revenue_cad => cad_revenue_currency_conversion,
:revenue_nzd => nzd_revenue_currency_conversion,
:status => average_change_interest,
:legacy_id => u.id)
end
end
puts "Successfully imported data from abc"
end
desc 'Imports def Data'
task :def_import => :environment do
# Connect to legacy db
class OldDb < ActiveRecord::Base
establish_connection :cleardb
self.table_name = 'def'
end
class Import < OldDb
self.table_name = 'def'
end
# Currency Conversion
require 'money'
require 'money/bank/google_currency'
# set the seconds after than the current rates are automatically expired
Money::Bank::GoogleCurrency.ttl_in_seconds = 86400
# set default bank to instance of GoogleCurrency
bank = Money::Bank::GoogleCurrency.new
#gbp = bank.get_rate(:USD, :GBP).to_f
#eur = bank.get_rate(:USD, :EUR).to_f
#aud = bank.get_rate(:USD, :AUD).to_f
#cad = bank.get_rate(:USD, :CAD).to_f
#nzd = bank.get_rate(:USD, :NZD).to_f
Import.all.find_each do |u|
# Define Variables
#price = u.UnitPrice
#interest = u.UnitSold
##interest_changes = u.unitsold_changes
#company = u.Company
#legacy_id = u.id
#end_date = u.EndDate
#category = u.Category
#revenue = u.Revenue
# Calculate average
#company_average = company_average(#company)
if #company_average == 0
#company_average = 1
end
# Does item exist?
if Product.exists?(:legacy_id => #legacy_id, :company => #company)
# It exists.
#historical_interest = Product.where(:legacy_id => #legacy_id).pluck(:interest)
# Another statement to check that the Interest != UnitSold
if #interest != #historical_interest
Product.where(:legacy_id => #legacy_id, :company => #company).update_all(:interest => #interest, :end_date => #end_date, :interest_changes => #interest_changes, :status => average_change_interest, :revenue => #revenue, :revenue_eur => eur_revenue_currency_conversion, :revenue_aud => aud_revenue_currency_conversion, :revenue_gbp => gbp_revenue_currency_conversion, :revenue_cad => cad_revenue_currency_conversion, :revenue_nzd => nzd_revenue_currency_conversion)
end
else
# Doesn't exist
# Set Categories
case #category
when 'Adult Products'
#category
when 'Arts & Crafts', 'Furniture', 'Garden', 'Large Appliances', 'Lighting', 'Outdoor & Patio', 'Stationary', 'Storage & Organization'
#category = 'Home & Furniture'
when 'Audio & Audio Accessories', 'Electronics Accessories', 'Gadgets', 'GPS & Car Accessories', 'Tools & Hardware', 'Tablets'
#category = 'Electronics & Accessories'
when 'Automotive Services'
#category = 'Automotive'
when 'Bath', 'Bedding'
#category = 'Bed & Bath'
when 'Books & Media', 'Canada', 'Gifts', 'Miscellaneous', 'Recreational'
#category = 'Miscellaneous'
when 'Cafe, Bakery & Treats', 'Kitchen'
#category = 'Kitchen'
when 'Casual Restaurants', 'Cleaning Services', 'Dance Classes', 'Fast Food', 'Fine Dining', 'Home Services', 'Local Exhibits & Shows', 'Other Services', 'Other Workshops & Classes', 'Outdoor Adventures', 'Other Activities', 'Tours & Sightseeing', 'Fitness Classes', 'Massage', 'Med Spa', 'Salon & Hair Care Services', 'Spa Services', 'Yoga, Pilates & Aerobics'
#category = 'Experiences'
when 'Cats', 'Dogs', 'Pets', 'Pets Accessories'
#category = 'Pets Accessories'
when 'Clothing', 'Clothing, Fashion & Accessories', 'Fashion & Accessories', 'Footwear', "Men's", 'Unisex', "Women's"
#category = 'Apparel & Footwear'
when 'Earrings', 'Fashion Accessories'
#category = 'Jewellery & Accessories'
when 'Fitness', 'Hair Care', 'Hair Removal', 'Health Care', 'Manicure & Pedicure', 'Other Beauty & Spa', 'Other Health & Fitness', 'Personal Care', 'Teeth Whitening', 'Wellness & Nutrition', 'Facial'
#category = 'Health & Beauty'
when 'Golf', 'Sports', 'Football', 'Baseball', 'Hockey', 'Ice Hockey'
#category = 'Sporting Accessories'
else
#category
end
Product.create(
:name => u.ProductName,
:link => u.ProductLink,
:image_url => u.ImageUrl,
:price => u.UnitPrice,
:interest => u.UnitSold,
:start_date => u.StartDate,
:end_date => u.EndDate,
:revenue => u.Revenue,
:company => u.Company,
:category => #category,
:country => u.Country,
:price_eur => eur_currency_conversion,
:price_aud => aud_currency_conversion,
:price_gbp => gbp_currency_conversion,
:price_cad => cad_currency_conversion,
:price_nzd => nzd_currency_conversion,
:revenue_eur => eur_revenue_currency_conversion,
:revenue_aud => aud_revenue_currency_conversion,
:revenue_gbp => gbp_revenue_currency_conversion,
:revenue_cad => cad_revenue_currency_conversion,
:revenue_nzd => nzd_revenue_currency_conversion,
:status => average_change_interest,
:legacy_id => u.id)
end
end
puts "Successfully imported data from def"
end

Answer 1

This indeed look repetitive, why can't you come up with a Structure like this and not put everything in below format
.
├── Rakefile
└── models
├── import.rb
└── old_db.rb
I did similar kind of thing, for one of my project where i am extracting data from a DB, you can also refer to it here https://github.com/ankit8898/sql-server-mapper