Fellow Railers, I don''t know how to handle this kind of situation the Rails way, please help. DB ---- create table products (id int not null auto_increment, name varchar(255), primary key (id)); create table batches (id int not null auto_increment, product_id int not null, quantity int not null, price decimal(10,2) not null, primary key (id), foreign key (product_id) references products(id)); create table serial_numbers (id int not null auto_increment, batch_id int not null, sn varchar(255), status char(1), primary key (id), foreign key (batch_id) references batches(id)); app/models ----------------- class Batch < ActiveRecord::Base belongs_to :product has_many :serial_numbers end class SerialNumber < ActiveRecord::Base belongs_to :batch end The problem ----------------- As you can see, I need to note the serial numbers for the products in stock. For a certain product, number of quantity in stock could reach hundreds. Thus, I will definitely not make a UI where user must enter the serial numbers one by one. Fortunately, the serial numbers are consecutive but in case that it''s not, user must delimit the serial numbers with comma. Example will be nice: Product A with quantity = 15 with serial numbers: 5692227750-5692227756 (7) 5638998830-5638998835 (6) 5638729480-5638729481 (2) User must type in an text_area: 5692227750-5692227756,5638998830-5638998835,5638729480-5638729481 In my opinion, I must: 1. Have a way to place a text_area that IS NOT data bound, then capture what serial numbers to the user type in. 2. Validates the serial numbers (see if the supplied serial numbers match the quantity) and create a SerialNumber object for each one of them 3. Feed the SerialNumber objects collection to Batch.serial_numbers 4. Save the Batch object. Rails will be smart enough to add those serial numbers to serial_numbers table. Am I right? If I am, then how to add a general (not data bound) text area to the "new" action of Batch controller? How to access the value that is typed-in by user, how do I validate the presence of serial numbers in the text area? I suppose I can add a column to table batches (for decoy) but I don''t want to. I have tried to add an attribute to Batch (ActiveRecord::Base) object just to fool text_area. However my attempt failed. Please advice. Thanks a lot. John