Export data from external source in a custom format like so –
mysql> select employee_no, username into outfile ‘/tmp/projX_users.txt’ FIELDS TERMINATED BY ‘,’ OPTIONALLY ENCLOSED BY ‘”’ LINES TERMINATED BY ‘\n’ FROM users;
Save the external data text file as a CSV in excel.
Create an import function on User model:
CSV.foreach(filename, :headers => false) do |row|
# Process each row from csv and create user object
user.create!(row.to_hash)
end
In a new rake file for custom tasks- /lib/tasks/custom_tasks.rake
namespace :import do
desc “Import from external data sources”
task :users => :environment do
User.import_users Rails.root.to_s + ‘/db/users.csv’
end
end
Run rake task:
rake import:users —trace RAILS_ENV=production
Don’t miss passing the environment as we have declared it as dependency in our rake task definition
References:
http://stackoverflow.com/questions/4410794/ruby-on-rails-import-data-from-a-csv-file
http://stdlib.rubyonrails.org/libdoc/csv/rdoc/classes/CSV.html
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