Displaying 20 results from an estimated 6000 matches similar to: "newbie q on activerecord - has_one and has_many on same table?"
2010 Feb 01
3
validating both sides of a has_one relationship breaks pickle/machinist tests
A lot has been posted about validation issues with associations,
however, I don''t see this issue addressed specifically.
ex:
class Foo
has_one :schedule, :dependent => :destroy
validates_presence_of :schedule
class Schedule
belongs_to :foo
validates_presence_of :foo_id
this creates a circular dependency that breaks test frameworks like
pickle and machinist.
At first I was
2006 Jan 18
2
categories/recipes & books/descriptions - has_many vs has_one => id question
People,
In the cookbook eg, categories has_many recipes but in a book eg, book
has_one description - doesn''t that mean that the id of the description
should be the same as the id of the book (instead of having it''s own
"description_id" in the book table?
Thanks,
Phil.
--
Philip Rhoades
Pricom Pty Limited (ACN 003 252 275 ABN 91 003 252 275)
GPO Box 3411
Sydney
2006 Feb 17
3
Using :include with has_one vs. has_many
While I''m happy to continue talking about the vagaries of Rails deployments, I
also need to actually build apps. :)
I may have discovered a bit of a problem with :include as it applies to has_one
associations. First, let me say that I''m a big fan of :include for reducing the
number of SQL calls. There are times when I wish it could go more than 1 step
away from the parent
2010 Aug 10
4
(Dreaded) STI, belongs_to
Having problems with STI. Names below have been changed to protect the
innocent. Imagine a system that allows someone to apply for one of two
different types of school scholarships. Each scholarship goes through a
different review process, represented by a state machine (this is not a
state machine question). So there are two state machine classes that
differ slightly and subclass a generic
2007 Aug 21
4
[AWDwR] Confused about has_one and has_many
Heya everyone!
I am quite new to Rails and I am reading AWDwR. I am at Task E "Check
Out!". I understand it quite well, but I have a problem with the last
playground exercise: Add a Table which contains the payment types.
All goes well, but I am not sure whether I should use has_many or
has_one(as in the Playground wiki at
http://wiki.pragprog.com/cgi-bin/wiki.cgi/PT-E-3).
I use the
2010 Dec 14
5
Build associated model confusion
I''m new to Rails3, and I''m just trying to get one last thing to work
before I call it a night. The situation is the following (please if
the code is horrible, just let me know, still learning):
I want to log a dive. I might have a new location on that dive at
which point I have to create a new Location, and then create the dive.
A dive has_one location. A location has_many
2006 Feb 20
1
belongs_to, has_one, has_many question (again?)
Hi All,
Probably this has been asked numerous times, I apologize already!
Can somebody point me to a good tutorial on how Rails works with
relations?
I know about database design and normalization, I also know about
programming in general (and OOP for that matter).
Only thing I can say is that I''m following the "Four days on Rails"
tutorial by John McCreesh.
He writes
2009 Oct 08
6
Eager Loading a Relationship That Has No PK/FK
I''m attempting to wrestle an old DB into Rails.
This relationship is giving me trouble:
class Show < AR::Base
has_many :segments
end
class Segment < AR::Base
belongs_to :show
has_one :media #this has no PK/FK relation
end
A Segment is "linked" to Media by Media.name, which is the result of
concatenating Segment.name and Segment.part. As I said there are is no
2010 Nov 11
5
ActiveRecord query
I have these sql code in postgresql
"SELECT * from convenios where id NOT IN
(SELECT convenio_id from solicituds where usuario_id=?"
but don''t find a way of used it in rails
except
find_by_sql.
There is a another way??
class Usuario < ActiveRecord::Base
belongs_to :persona
has_many :solicituds, :dependent => :destroy
has_many :convenios, :through =>
2006 Jun 21
1
ActiveRecord has_one default value
My apologies if this is a dumb question, but I''ve searched around and
haven''t been able to come up with a solution.
Is there a way when specifying a has_one association to specify a
default value for an object if data is missing in the child table. For
instance:
class Student
has_one :university
end
if no university is associated to the student in the database, I would
2008 Sep 16
3
has_one :through eager-loading problem
I have a problem with the :include option in find for my
has_one :through association.
I have Users, Profiles and Customers, all connected to each other with
a has_one :through => :membership association like this:
class Profile < ActiveRecord::Base #could also be user or customer
has_one :membership # i saw an acrticle of Ryan about
has_one :through, there this would be has_many, is
2010 Aug 19
4
Subclassing a model
Is it possible to define a subclass for a model, that defines additional
data columns, which are stored in a separate table?
Is there any description, how to do this?
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2006 May 12
1
can I fake has_one :through?
I''m having a difficult time wrapping my head around a set of models
and their associations and seeing how they map into Rails. I''ll try
to lay out my problem using the has_many and belongs_to structures. I
have a RuleSpace, a Rule, and a Subject.
A RuleSpace has_many Rules
A RulesSpace has_many Subjects through Rules
A Rule belongs_to (many) RuleSpaces
A Rule has_many
2007 May 14
0
building and saving has_many and has_one relations
Hi,
I am very confused about an aspect of has_one and has_many relations,
with regard to using the build method, and saving the belongs_to side.
It''s a somewhat long post. so please bear with me :)
First let''s consider the has_one scenario. Let''s say I have a student
who must own exactly one car:
class Student
has_one(:car)
end
class Car
belongs_to(:student)
2006 Apr 07
2
has_one not using the pk?
Hello,
im trying to wrap a fairly ugly legacy schema using AR. How to handle
normalized informations which aren''t connected via the pk?
create table what (
myid int,
myclass int, ;; references blahclass.blahid
mygender int
)
create table blahclass (
blahid int,
mdesc1 text,
fdesc1 text)
)
I would like to wrap this as
class What < AR::Base
has_one :blahclass
class
2007 Dec 06
0
has_many :through with a has_one source
Here is my simple example...
require ''rubygems''
require ''active_record''
ActiveRecord::Base.establish_connection :adapter =>
"sqlite3", :database => "has_many_through.db"
ActiveRecord::Schema.define do
create_table "containers", :force => true do |t|
t.column :name, :string
end
create_table "shapes",
2005 Dec 29
0
Problem destroying some record with relations has_many has_one
Hi guys!
I''m developoning a small web-app, everything goes quickly and well!!
I need some help, im trying to destroy at the same time some records of
varius of my models. My model are relathionate with has_many, has_one.
What could be the best way to do it? Could i use act_as_a_tree or there
are other cool way?
Thanks
P.D: Sorry by my bad english
2009 Jul 15
0
has_many and has_one ... and nested form
Hiya
I am looking at Rails 2.3.2 and how to cleanly do the following:
- I have model User
- User has many Plans
- User has one Active Plan
- New User form has fields on it to create the Active Parent
I want to create a new User with an Active Plan in one form.
At the moment I have:
class User < ActiveRecord::Base
has_one :active_plan, :class_name => ''Plan'',
2007 Apr 21
0
has_many / has_one polymorphic with conditions
I''m looking for a way to make this work (I think the code is more
explanatory at this point):
## THIS WORKS
has_many :images, :as => :imageable, :dependent => :destroy, :order =>
''position ASC''
# @product.images => #
## THIS DOESNT
has_one :featured_image, :as => :imageable, :conditions => "position =
1"
# @product.featured_image =>
2010 Feb 10
2
undefined method 'state'
I can''t imagine what I''m trying to do is complicated at all in Rails.
Yet, I am now getting this error: undefined method `state'' for
:StudentFailState:Symbol.
student.rb
has_one :student_fail
attr_accessor :student_fail_attribute
#controller
def student_fail
@student = @student.find params[:id]
def update_student_fail
@student.build_student_fail