Displaying 20 results from an estimated 10000 matches similar to: "Models that reference themselves"
2006 Apr 09
1
select helper question
Hi there, I try to develop a medical application using ruby on rails.
There are many categories which can contain subcategories.
I defined the model like this:
class Category < ActiveRecord::Base
has_and_belongs_to_many :notes
belongs_to :parent_category, :class_name=>"Category",
:foreign_key=>"category_id"
has_many :sub_categories,
2009 Feb 19
3
Associated child records not created on creation of a parent.
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
2006 Jan 09
1
Saving an upload
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,
2005 Jul 25
2
acts_as_tree and traversing parent/child relationships
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
2006 Oct 22
3
Keeping DRY - I like a simple life!
Hi,
I''m new to Ruby and Rails and I would be very grateful for some advice.
I''ve got the following code.
class Foo < ActiveRecord::Base
include Versionable # Some methods to handle my versioned objects
has_many :versions, :class_name => "FooVersion", :foreign_key =>
"parent_id"
belongs_to :curr, :class_name => "FooVersion",
2009 Mar 08
2
RESTful nested resources and polymorphism?
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
2005 Dec 14
5
belongs_to and multiple foreign keys
Hi all,
I''m confused about how I''m supposed to specify a belongs_to relationship when
the table includes multiple columns that reference the same parent table.
In my case I have a "schedules" table with "opened_by" and "closed_by" columns,
that both reference the "users" table. In theory, they can be two different
user ids.
table
2005 Dec 19
4
need some help designing my messaging system
I am trying to create a messaging system for my users but I''m having a
hard time designing my db. This is what i have in mind, but I am not
sure if its the best approach.
user has_one inbox
user has_one outbox
inbox has_many messages
outbox has_many messages
inbox table
user_id
outbox table
user_id
messages table
box_id (refers to either inbox or outbox - how?)
from_id
to_id
2007 Sep 06
4
HABTM association with own class?
If I have a class, Asset, which has and belongs to many associated Asset
objects, how do I do this?
has_and_belongs_to_many :associated_assets, :class => "Asset",
:foreign_key => ?????, :association_foreign_key => ?????
Right now, my table has a :first_asset_id and a :second_asset_id, but I
don''t see how the objects themselves are supposed to distinguish one
from the
2006 Feb 27
4
2 belongs_to to the same parent table
Hello!
I have 2 table: users and buddies
User: id, name, ...
Buddy: id, user_id, user_buddy_id, ...
So if you have 2 users 1,jack and 2,fred and fred is a buddy of jack,
there is a Buddy object: id=1, user_id=1, user_buddy_id=2
I can declare only one belongs_to in Buddy and one has_many in User. And
there is conflict if I had the second one (the first one is discarded)
class User
has_many
2006 Jan 13
4
Single Table Inheritance (this is my 3rd post :( )
Hi Everyone,
I hope I get some feedback on my question. Here it goes.
I have a situation here, I have a company table and then using Single
Table inheritance it is of 3 types:
class Company < ActiveRecord::Base
end
class Vendor < Company
end
class Customer < Company
end
class Agent < Company
end
Now I have a active record Association
class QuoteSheet < ActiveRecord::Base
2007 Aug 23
6
Calling a method on class creation
I have a model User that has property called status. Status is just a
string that can only be evaluated and not persisted. I.e. it doesn''t
have a field in the user table.
Anyways, I would like a method get_status to be called anytime I
create a new instance of User. For example:
user=User.new
Since I created a new instance of User, I should now have access to
the status property, e.g.:
2006 May 30
2
acts_as_tree, acts_as_list and is invincible (help!)
So I have the following model
class Topic < ActiveRecord::Base
belongs_to :topic
has_many :topics, :order => :position
acts_as_tree :order => :position
acts_as_list :scope => :topic_id
end
that I use for a site''s navigation. Everything (list, create, edit, even
the drag&drop sort) works fine, except the destroy function, which the
vanilla version
def destroy
2008 Jul 15
9
Beginner Question.
I''m just getting into RoR, coming from a long PHP background. So far I
LOVE IT!
I''m hitting a roadblock with updating my mysql database. For
simplicities sake, I have 2 tables and here are the relevant columns.
Table Users
id
name
email
Table Issues
id
createdby
assignedto
reportedby
In my models I have everything mapped properly I believe.
When I try to update the
2006 Apr 04
4
Aggregating two objects of the same type
I would like to have a customer that has references to two addresses,
a billing address and a shipping address. In a non-rails environment
I would have two keys in the customers table, billing_address_id and
shipping_address_id to reference the addresses. It appears that
ActiveRecord expects the parent id to reside in the child table,
regardless of whether the relationship is one-to-one or
2005 Mar 08
15
Rails 0.10.1and WEBrick
Doesn''t appear to work with WEBrick. Works find with Apache/FastCGI.
Something wrong in the way Rails is trying to process paths from the
WEBrick server. If I try to send in http://localhost:3000/recipes/new,
WEBrick is interpreting /new as my controller, instead of my action.
2006 Apr 25
3
belongs_to and has_many
I know this has been rehashed many times, but I don''t get it.
I can''t find it documented to were I understand all the parts. I can
make this work using Rails database design conventions, but in this case
I am not able to do that.
I find examples, but the ones I find do not follow the conventions.
They also do not give enough information to understand what is going on.
In
2008 Jun 13
6
Newbie question on has_many
I have two classes: a Widget and a User. The User has an id that is
referenced in two places on the Widget: owner_id and operator_id.
How should I structure that reference for has_many?
Thanks folks - I appreciate any help on this.
--David
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2006 Jan 06
2
Re: Some advice on DB modeling
I have more or less the same problem. I''m trying to build a system where
users can enter their friends. But the solutions seems not to work for me.
I used same sql:
CREATE TABLE `friends` (
`user_id` int(11) NOT NULL default ''0'',
`friend_id` int(11) NOT NULL default ''0'',
KEY `user_id` (`user_id`),
KEY `friend_id` (`friend_id`),
2007 Jul 26
1
Bi-directional self-referential HABTM
Hi,
I''m having a little trouble figuring out how to make a self-
referential HABTM bi-directional.
I have a Employee class. Each employee can have a couple of bosses,
who are also employees. The employee class has the following HABTM:
has_and_belongs_to_many :bosses, :class_name =>
"Employee", :join_table => "bosses_courses", :association_foreign_key
=>