Displaying 20 results from an estimated 8000 matches similar to: "ActiveRecord::Associations ER diagram/macros"
2005 May 14
2
ActiveRecord::Associations::ClassMethods Documentation Issue
I''m curious, but isn''t this example in the documentation for
ActiveRecord::Associations::ClassMethods somewhat counter-intuitive? The SQL
DDL is correct for the way it''s used in the models. But isn''t it more
logical that an author would have many posts, rather than many authors
having one post?
From
2006 Apr 04
4
Find records based on associated table''s colums
Hello,
Let''s say I have a model for a "house". Each house has_a "city", which
in turn has_a "state" which in turn has_a "country". The objective is to
retrieve all houses in a given state, say "Massachusetts".
Being new to Ruby on Rails what I like is that things that should be
simple usually are simple, and since we have easy access to
2006 Jan 06
0
bug rails activerecord association join
hi,
I found a bug in ActiveRecord association SQL INNER JOIN codes. in
has_many, has_one, habtm and belongs_to queries the foreign key is
determined from the table name of reflection and self. but that''s
worng because if you use a global prefix or suffix for your tables the
foreign keys will be in format of PREFIX_CLASSNAME_SUFFIX_id which is
wrong, because it breaks the advantage of
2006 Jan 26
1
Explanation on Activerecord Associations
A while back, I had some doubts on the use of associations. I still
haven''t got a satisfactory guidance so that I can spring ahead with the
project. I am trying to understand from a ruby point of view on doing
things. Basically I have a controller that gives me a list of students.
And each student may have say home address and mailing address. Hence I
can model as shown below. How do I
2005 Mar 01
1
rename associations
Greetings all,
In looking at the API for ActiveRecord::Associations::ClassMethods there
doesn''t appear to be a way to rename an association. In doing some
refactoring I am replacing one table with two but want to preserve the
old associations names, e.g. I want to be able to still say
build_type.artifacts instead of having to use the new table name:
build_type.build_type_artifacts.
2006 Jul 31
0
Patch for #3438: Eager loading doesn''t respect :order of associations
Hello all,
I still have a patch for #3438 (eager loading doesn''t respect
association orders); it passes all unit tests, and has additional unit
tests with full coverage. The patch is attached.
== The Bug ==
Author.find(1).posts != Author.find(1, :include => [:posts]).posts
if Author has_many :posts, :order => anything.
This means that either one must avoid eager loading or
2006 Jun 03
1
Can I tell if the associated record is new in a belongs_to save?
In a belongs_to association, is there a way to tell if the associated object
was newly created?
Hopefully this will explain my question:
A Firm class declares
has_many<http://api.rubyonrails.com/classes/ActiveRecord/Associations/ClassMethods.html#M000530>:clients
and a
client class declares
2006 Jul 05
1
newbie question: Mapping Collections
Hi,
Day 3 with rails here. Forgive me. If this has been covered many times
before, pls just point me at the article.
I worked through the Rolling with Rails tutorial
(http://www.onlamp.com/pub/a/onlamp/2005/01/20/rails.html) built up my
cookbook. Things work great.
I now want to add Ingredients to my app. So, a Recipe will have 1 or
more Ingredients and any single ingredient can be
2007 Sep 26
0
activerecord multiple databases
So, I was looking for a setup that would allow me to easily query
multiple databases and not have to re-write my customer finder type
queries. Here is what I came up with and it seems to be working for
me in my very basic tests so I thought I''d share. Just posting it in
case this helps anyone else trying to do the same thing.
I''m using this with activerecord, but not rails, so
2005 May 13
17
modeling...
I''ve tried tackling this many ways on my own and can''t find a good solution:
Breaking it down to something simplier...
Venue
has one address
Person
has one address
Address
belongs to state
Assuming I don''t want to do tables for venue_addresses and person_addresses.
What is the best way to model this using rails... big thing here is i
want to be able
to reuse a
2008 Jul 17
0
How to Reverse Engineer ER Diagram from Mysql
Morning everyone,
I was going to ask someone here about how to reverse engineer a schema
diagram from Mysql and visio because its hard to locate such information
(http://techpanacea.blogspot.com/2008/07/creating-entity-relationship-diagram.html
and the one place where its listed by google requires payment or
registration)
So i put it up here :
2007 Jun 16
1
extending activerecord base with after_initialize
hi,
i am having problems getting after_initialize for activerecord
subclasses. basically, i am trying to use the guid plugin by andy
singleton. i am having problems extending the class to the plugins i
installed, so i figured i will just apply this to all the models in my
project. i trled to add the following to my lib/ folder. my goal is
to extended the activerecord class so that it uses
2006 Mar 02
1
ActiveRecord in modules & associations
I''d like to organise my active records into modules but can''t get the
associations to work. The doc says that associations within the same
module should work. I''ve tried using the class_name option too but still
doesn''t work.
Can anyone help?
For example
module Mod1
class Animal < ActiveRecord::Base
has_many :dogs, :class_name =>
2006 May 05
0
Missing documentation for find_in_collection? Trying to drill down in a 4 level has_many association fails
I''ve been reading up in ActiveRecord::Associations and playing around
with my app via the console and found some interesting methods via
the code completion of IRB, but I have no idea how to use them and
can only find one hint in the API
http://api.rubyonrails.com/classes/ActiveRecord/Associations/
ClassMethods.html
It mentions here in the has many associations that if you use the
2006 May 11
6
ActiveRecord associations
Can someone clarify this for me? Suppose I have two tables like:
class Company < ActiveRecord::Base
belongs_to :category
end
class Category < ActiveRecord::Base
has_many :companies
end
I understand that the belongs_to causes related companies to be read
from the db when I ask for a category. I suspect SQL something like
select * from categories, companies
where category.id
2006 Jun 14
3
Prevent duplicate HABTM associations
Hi,
I am trying to restrict duplicate has_and_belongs_to_many associations.
I tried to find support for a association validation for duplicates but
couldn''t find anything.
I understand I could use :uniq=>true on the model association but this
would only prevent it from displaying duplicates, I want to stop
duplicate associations being inserted in the first place.
I have a vague
2006 Jan 13
1
association callbacks
Hello all. I am looking for some feedback on an implementation. I''m writing
a plugin that will log all model changes. I do not want to have to add a
line a code for this functionality every time I create a model. Instead I
create a table with the name <model>_changes.
The basic stuff was easy:
base.after_create {|model|
model.log_create if model.has_backup_table?
2013 Nov 30
1
Need good tutorial on ActiveRecord associations
Hi,
I am very new to rails.. I am having hard times to understand the
ActiveRecord associations.. I tried
http://guides.rubyonrails.org/association_basics.html .. But it is not
for beginners. :)
Is there any good tutorials, to understand the concept?
Thanks
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2010 Mar 10
0
Rails ActiveRecord associations autosave option
I have the following associations.
class Document < ActiveRecord::Base
has_many :document_sections, :dependent => :destroy, :autosave => true
has_many :document_items, :through => :document_sections
end
class DocumentSection < ActiveRecord::Base
belongs_to :document
has_many :document_items, :dependent => :destroy, :autosave => true
end
class DocumentItem <
2006 Feb 02
0
proposed bugfix/patch: ActiveRecord cross-module associations
Hi,
I''m still test driving the improved support for module namespaces in
rails and I''ve hit a problem with associations between AR classes in
modules and AR classes in the root namespace.
The long and short of it is I want to be able to say:
Foo::Bar.belongs_to :wibble, :class_name => "::Wibble"
If you don''t try to prefix ''Wibble''