similar to: has_many through - getting the parent

It seems that using a join model that joins with two has_many''s will fail to generate proper SQL class StudentSemesterRecord < ActiveRecord::Base belongs_to :semester has_many :discipline_records, :through => :semester end class Semester < ActiveRecord::Base has_many :student_semester_records has_many :discipline_records end class DisciplineRecord <

Hi All, I need your suggestions for the following. I am still learning RoR and pardon my ignorance. I have say two tables. Table A : students Table B : addresses Table B has student_id as the foreign key to Table A If I am displaying the list of students and wanted to get individual students addresses based on their id, is the only option is to get the id from students controller method list

Hi I have a has_many :through. It''s a basic mapping of Project id .... User id .... TeamMembers project_id user_id role What I would like to do is have different roles so I can have in the project model has_many :core_members, :through => :team_members, :source => :user but I would like to limit this to only those with the "core" role in the team members table for

I just took my HABTM and turned it into a :through since my join table has another "non-joiny" attribute. I went from this: has_many_and_belongs_to :jobs, :join_table => ''tablename'', :foreign_key => ''x'', :association_foreign_key => ''y'' to this: has_many :jobs, :through =>

I have this code that is using svn externals with rails EDGE working fine for the past couple of months. A couple of days ago, this code died. Even after deleting vendor/rails, this code doesnt work: class Tag < ActiveRecord::Base has_many :taggings has_many :events, :through => :taggings has_many :users, :through => :taggings end class User < ActiveRecord::Base # Virtual

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

So having just learned how to do has_many :through as opposed to HABTM, and then, being concerned that I wouldn''t get it to work, I started thinking about these two approaches. It seems to me that the _only_ problem that the HM:T (has_many :through) approach solves that HABTM doesn''t is the issue of the potential collision of id columns between your join table and one of

I''m trying to use has_many :through, since my join model deserves being more than just an intersection table. But when I try to break the association, the break only seems "temporary": Let''s say my two tables are Users and Colors, and the join model is Favorites. user = Users.find(1) user.colors.length >> 2 c = user.colors.first >> #<Color:....>

I''m working on a simple photo gallery in rails, it seems to be a good project for a newbie. I have photos and categories, many-to-many association. It worked well with HABTM. Then I decided that it would be good to be able to change order of the photos so that thumbnail pages would look less chaotic. So I created a Layout model which is a join model (or whatever it is called) that

Hi, I have a self-referential has_many :through relationship setup to track relationships between users. Basically relationships are modeled as a join table with an extra column ''relation''. create table relationships ( user_id integer unsigned not null, friend_id integer unsigned not null, relation char(1) not null, ) --- relations --- f = friend r = request to

Hi all. I am currently thinking about how to do the following: I have the following models. Team Person Team has various positions (manager, programmer etc.) I would like each one of those positions to reference one or more Person records. A single Person record could be on 6 different teams at the same time in different roles. the same person could even be on the same team multiple times

Hi, Four tables: users, user_counties, uk_counties and us_counties. Each user has many counties, and each county has many users, so I decided to make user_counties a polymorph, so it can have counties from different countries (each country requires a completely different set of tables with a completely different set of properties, that''s why there''s one table for uk_counties and

If I have a model called Newsletter with: has_many :subscribers, :through => :subscriptions and wanted to list all the subscribers, but show what level their subscriptions was (level is in subscriptions table), how would I best do that? Do I have to use my own select to get what I want or are the attributes from subscriptions available to me through the join somehow (I am suspecting not)?

I wonder if you can have more than one has_many :through association between 2 models. For example... I have a model Teacher and a model Class Now, 1 Teacher works in many Classes, right?. So I need a join model like class Work < ActiveRecord::Base belongs_to :teacher belongs_to :class end But I also would like to know if a teacher CAN teach a class before I

Hi all, I have a relationship (no really!) class RiskMatrix < ActiveRecord::Base has_many :severities, :order => :position, :uniq => true end class RiskFactor < ActiveRecord::Base belongs_to :risk_matrix validates_presence_of :descriptor, :example validates_uniqueness_of :descriptor, :example, :scope=> :risk_matrix_id end class Severity < RiskFactor

Having a devil of a time finding records in a self-referencing has_many table relationship. Everything is working find looking at the has_many and the belongs_to relationship. But, when I try to find all "orphans", records that are neither a parent nor a child, I can not find a query that work in ActiveRecord. This query works in MySQL: SELECT * FROM templates LEFT JOIN templates

I have a model that looks like this: class Actor < ActiveRecord::Base has_many :member_groups, :foreign_key => ''member_id'', :class_name => ''GroupMember'' has_many :groups, :through => :member_groups, :source => :group end class Group < Actor has_many :group_members, :foreign_key => ''group_id'',:dependent =>

Hello all. I am trying to create a self-referential has_many :through. I used the following site as a guide http://blog.hasmanythrough.com/articles/2006/04/21/self-referential-through but it still doesn''t appear to be working. I have two models. Person and Relationship. A person has many contacts (Which is another person) through relationships class Person < ActiveRecord::Base

Does anyone have an efficient/elegant way to prevent duplicate inserts when using a has_many :through relationship. So I have something like this: class User < ActiveRecord::Base has_many :favorite_teams has_many :teams, :through => :favorite_teams end class FavoriteTeams < ActiveRecord::Base belongs_to :user belongs_to :team end class Teams < ActiveRecord::Base has_many

I have the following model structure setup. class User < ActiveRecord::Base end class Parent < User has_many :relationships has_many :children, :class_name => "Student", :through => :relationships, :conditions => "related_as = ''parent''" end class Student < User has_many :relationships