similar to: destroy on has_many relationships.

disclaimer: am in the midst of my first ruby/rails project I have a situation where I want several child records to be created when a new parent record is created. The following represents my first stab at coding it, am I on the right track? Here is the model: parents ---------- id name children ---------- id parent_id name class Parent < ActiveRecord::Base has_many: children end

If I have... class Parent has_many :children end class Child belongs_to :parent end ...then... * Assigning a _new_ child during parent''s creation saves the child record with the parent''s id. child = Child.new Parent.create(:children => [child]) # Results in child being associated with parent * Assigning an existing child after a parent''s creation

I have a couple of resources, one nested in the other, such that my resource spec in routes.rb is: map.resources :parents, :has_many => :children This will generate a route for a new child that assumes that the parent has already been saved, something like: /parents/:parent_id/children/new But what if I want a route that handles the case where the parent resource is also new, and thus

Ok, So, I''ve got two data tables associated through a foreign key. class Child < ActiveRecord::Base belongs_to :parent, :class => Parent, :foreign_key => "parent_id" # also has attr1, attr2 end class Parent < ActiveRecord::Base has_many :children, :class => Child, :foreign_key => "parent_id" end So, I''m trying to build the new/edit

I am working on an Rails application that uses a pretty complex category structure through out the site. I have defined a table to house all the info and a FK to reference parents within the table CREATE TABLE categories ( id int(11) NOT NULL auto_increment, name varchar(50) NOT NULL, parent_id int(11) default NULL, constraint fk_category_id foreign key (category_id) references

Let''s say I have simple schema with two tables. The models are defined like the folllowing: class Parent < ActiveRecord::Base has_many :children end class Child < ActiveRecord::Base belongs_to :parent end Simple has_many relationship. Is there any way to order the results of a Parent.find_all by the number of children the parent has? I can sort with sorted_parents =

Hi, I''m using the latest gem version of rails under MacOS Tiger. I was trying to use acts_as_tree as described in the rails book. So I have something like: class Category < ActiveRecord::Base acts_as_tree :order => "title" end create table categories ( id int not null auto_increment, title

With ref to my previous post: http://www.ruby-forum.com/topic/180356 I am now able to access items from topics controller. However, now I need to add sub-item e.g.: An item itself could have many sub-items. So my items model is like: class Item < ActiveRecord::Base validates_uniqueness_of :title, :scope => [:topic_id] validates_presence_of :topic_id, :title, :owner, :position

If i have a parent that has_many :children, and the child belongs_to :parent. Then when I add a new child to the parent like so: parent.children << Child.new, then shouldn''t the child also have a reference to the parent? but it doesn''t-- child.parent is nil-- what''s going on here? is this as it should be-- shouldn''t it have a reference to the

I have a model "Childmodel" that belongs_to two other models "Parent1" and "Parent2". "Parent1" "has_many :childmodels, :order => :positionp1" and "Parent2" "has_many :childmodels, :order => :positionp2". i.e. The child is independently positioned within each of its parents. This works fine and gets me the useful

As far as I can tell, the counter_cache option on a belongs_to model doesn''t actually save anything in the database. For example, I have the following models: class Parent < ActiveRecord::Base has_many :children, :conditions => "deleted_at IS NULL" end class Child < ActiveRecord::Base belongs_to :parent, :counter_cache => true end With the following

i''m still pretty new to rails, and while i''ve been able to hack my way into having it do what i want so far, i''m not happy with the way my code looks. on top of that, i''m sure that what i''m doing prlly isn''t the most efficient either. one of my biggest problems is probably to do with using relationships and forms together. i''ve

Hi I''m pretty much a newbie to Rails and I have at least two projects under development that are going to need the same type of constructs and I''m struggling to get my head around how to achieve what I want using Rails models and relationships. In one project I have a hierarchy of (geographical) sites. For example: Earth Europe Ireland Cork Kerry Galway

I am creating a database for movies (films) and television shows (shows) that will have has_and_belongs_to_many relationships with the pictures table. CREATE TABLE screenshots ( id serial NOT NULL, filename character varying NOT NULL, content_type character varying NOT NULL, primary key (id) ); CREATE TABLE films ( id serial NOT NULL, name character varying NOT NULL,

I''ve been stumbling on the tut at oriontransfer (http://wiki.oriontransfer.co.nz/main/show/SortableTree) I''ve got it working in a one dimensional list and I''ve got the drag and drop working on children, but as can''t get it to save the tree. Here''s my view: <h2>Menu Prototype 2</h2> <%= flash[:notice] %> <ul

I am trying to create a record with association. Within the create method, I would also like to pre-populate dependent (has_many) records from a template in the database. The child records are <u>mysteriously rolled back </u> if I insert them in a loop. If I try to insert a single child record, it works.I have read the books and tried to google my way out of this but am at a dead

So I''ve worked through Agile Web Development with Rails and I''m now trying my first little app to get into the swing of things. Its a task tracking app where people can create tasks and assign them to others, and also log time against the tasks. I''m having trouble working out the model relationships. This is what I''ve got so far, but its not right as

Basically, I''m trying to have a table called "categories" have a many to many relationship with itself. But I also want each catagory to be able to be "copied" into another category so it is essentially a child category to more than one parent. To me the obvious way of doing this is by creating another table called category_maps (and a model called CategoryMap).

hi, I''ve got the following tables in mysql notation: CREATE TABLE `nodes` ( `id` int(11) NOT NULL auto_increment, `parent_id` int(11) default ''0'', `group_id` int(11) default ''0'', PRIMARY KEY (`id`), ); CREATE TABLE `groups` ( `parent_id` int(11) NOT NULL default ''0'', `id` int(11) NOT NULL auto_increment,

Hi i am trying to figure out what is the best way to do this very basic thing: lets say i have two tables: one with parents and one with children. there is a one to many relation between them. I scaffolded the parents tabel and i can open each parent. Now i want to add a link to the ''show'' view which will create a new child record. In the model i defined the has_many and