similar to: AR - Delete m:n Associations when deleting Record

So I want to SELECT from multiple tables, so as to be able to do "SELECT FROM foo, bar WHERE foo.id=bar.id AND bar.baz=23". How do I do it with AR#find? Also, I need this for associations. has_many et. al. have :finder_sql, which is nice, but feels like a Pyrrhic: it''s basically doing the association in pure SQL, defeating the purpose of AR. -- -Alder

Dear List, I''m using Edge Rails. I have a Model with Items for purchase. Each Item is of a certain brand. Class Brand < ActiveRecord::Base end Class Item < ActiveRecord::Base belongs_to :brand end The problem domain is that I''d like to create a separate Inventory list of Items. This includes the date of entry into inventory and date of exit from inventory (ie

class Patient < AR::Base has_many :aaas has_many :bbbs ,:through=>:aaas end class Aaa < AR::Base has_many :bbbs end ------- i want like this @patient=Patient.find(id) @new_patient=@patient.duplicate now the @new_patient should have their own copy of patient,aaas,bbbs (new records in corresponding tables) there is one options is that we can create seperate object for each

If anybody on edge familiar with this could help, that would be "great" :) I have different types of things I want to be "reviewable". So, instead of having a slew of HABTM... this new Polymorphic Associations schtick seemed like the best solution. I have everything setup as I thought it should be (so I think)... but it doesn''t appear to be working correctly. Here

Hi all. Got a stupid-simple question about associations. I have two models - school and course. There are a fixed number of schools (set up in the migration). Each course is assigned a school and a school will be associated with multiple courses... How do I set up the associations? Do (can) I have School :has_one :course and Course :has_many :schools? Does the schools table then get a course_id

The below query fails: Timesheet.joins(:time_entries).select("timesheets.*, sum(time_entries.worktime) as total").group("timesheets.start_date") The models have the following relations: Timesheet < AR has_many :activities, dependent: :destroy, inverse_of: :timesheet has_many :time_entries, through: :activities accepts_nested_attributes_for :activities,

I have two class, client and contacts A client has many contacts class Client < ActiveRecord::Base has_many :contacts end class Contact < ActiveRecord::Base belongs_to :client end -------------------------------------------- I have the next data Table clients id name 1 John Table contacts id email 1 john@yahoo.com.ar 2 john@gmail.com 3

I seem to be getting some behaviour thats unexpected (for me anyway) when using find_by_contents on an ActiveRecord has_many association. The results that are returned are only the records that belong to the model returned, but the total_hits that are being returned appear to be for the whole table. e.g. class Book < AR::Base has_many :pages end class Page < AR::Base belongs_to :book

Wow, got myself lost as *soon* as I left the hand-holding exercises in the books. I''m trying to set it up so when I click the (scaffold-generated) ''destroy'' link on one (of a list) of parent MySQL records, the children records in a different table get deleted also. Very simple setup: my tables are ''customers'' and ''accounts'' class

When I do a to_xml(with a block) on an association of a model I got a Builder::XmlMarkup#to_ary should return Array Example that does not work. @intervenant = Intervenant.find(params[:id]) output = @intervenant.to_xml( :skip_types => false, :dasherize => false) do |xml| @intervenant.individu.to_xml( :builder => xml, :skip_instruct => true, :skip_types => false,

Hi there, I''ve been working on this for awhile and have finally decided to ask for a little guidance.I have a slight problem trying to save a selection. I have two models: A "Posting" has_many "Categories", and a "Category" belongs_to one "Posting". With that said, in the posting model I have "has_many :categories" and within the

My question is whether the rails helper methods for handling associations can be nested (see examples below). I suspect not as currently I''m getting "unknown method" if I try and use two associations in one call. The essence of the code is class User << ActiveRecord::Base has_many :items class Items << ActiveRecord::Base has_many :reservations belongs_to

Hi everyone, I''m currently finishing the planning phase of a small project I want to create. I read a bunch of tutorials about ActiveRecord and the different way to link your "tables" with belongs_to, has_many, has_and_belong_..., etc... However I''m stillnot sure if what I''m trying to do will work *well* with ActiveRecord. So enough talk,

Hi. I have a couple of best practices questions regarding polymorphic associations, naming join tables and user permissions. Currently I have implemented the user authentication model from the rails recipes book. Basically it goes something like this: MODEL CLASSES: class User < ActiveRecord::Base has_and_belongs_to_many :roles end class Role < ActiveRecord::Base

Hi, I haven''t done any associations before, so please forgive my incorrect use of terminology... If I set up a has_many :through association, can I manipulate the associated instances directly (like an Array), or do I need to manipulate the join model? For example, suppose I have two classes and the associated join model: class foo has_many :foo_bars has_many :bars, :through

Considering an object with several has_many :through => associations, what is the ''best'' way to handle validations? As an example: class Student < ActiveRecord::Base # some attrbutes like # :name # :grade # relationships has_many :students_assignment, :dependent => :destroy has_many :assignments, :through => :students_assignment has_many

I suspect that this is going to wind up trivial and I''m going to slap myself in the head... Suppose I have User and Comment AR classes. User has_many :comments, Comment belongs_to :user I want to do a User.find, which returns User objects in order of which user has the most comments. I suspect that this involves renaming the COUNT(*) results of a sub-select so that I can order by

hi folks. on rails 4, can somebody confirm that pushing model instances onto a has_many :through relation does not create the necessary join model anymore? class Reader < AR::Base belongs_to :post belongs_to :person end class Post < AR::Base has_many :readers has_many :people, through: :readers end @post.people << Person.new so,

Hi everyone. I''ve made a default change to has_many :through associations that I felt was important to make before they''re released. This is after some tickets and confusion I''ve seen regarding has_many :through. class Connection < ActiveRecord::Base belongs_to :user belongs_to :channel end class Channel < ActiveRecord::Base has_many :connections

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