Displaying 20 results from an estimated 7000 matches similar to: ":limit => Parent / Child Relationship"
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
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
2010 Aug 05
3
how to ? Rails 3 ActiveRecord eager loading and AREL
Hello everyone,
I would like to eager load scoped records to avoid queries executed in a
loop (huge performance impact).
The "scoped" part is what is giving me a hard time.
I''m using Rails3 RC.
Does anyone have any idea how I can do it?
Here is a test case : we have an "Article" and a "Comment" Activerecord
models,
article has many comments
comment
2006 Mar 07
13
Active Record - Can''t figure out relationship.
I have the following two tables:
create table teams (
id int not null auto_increment,
short_name varchar(12) not null,
long_name varchar(50) not null,
logo varchar(20) not null,
primary key (id)
);
create table rounds (
id int not null auto_increment,
home_team_id int not null,
away_team_id int
2006 Aug 15
2
How to access attribute in a self-referential many-to-many relationship
Hello List,
I created a self-referential many-to-many relationship (as described
in the book Rails recipe #18), where I have a model that has
many-to-many relationships with itself. In this case, it''s person who
can become friends. The join table looks like this:
mysql> select * from friends_people;
+-----------+-----------+-----------+
| person_id | friend_id | confirmed |
2006 Apr 12
2
ActiveRecord Parent-Child relationship bug? config problem?
If i have a parent that has_many :children, and the child belongs_to
:parent. Then when I add a new child to the parent like so:
parent.children << Child.new, then shouldn''t the child also have a
reference to the parent? but it doesn''t-- child.parent is nil-- what''s
going on here? is this as it should be-- shouldn''t it have a reference
to the
2006 May 28
7
Self-referential has_many :through relationship
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
2006 May 23
1
Validating a required relationship.
Hello,
I''m not sure if I''m missing something blindingly obvious here.
All the relationships that Rails comes with assume 0..n, yes? It''s
not a strict 1 to 1 or 1 to n because it''s optional. My question is
this -
What is the best way to implement a required relationship?
For example, if I require that a comment is made by a user (a user
has many
2013 Feb 08
1
Problem with many to many relationship
Hi
I''m trying to create a many to many relationship between two models.
A User can be associated with many Incidents and vice versa.
class User < ActiveRecord::Base
include ActiveModel::ForbiddenAttributesProtection
has_many :incident_participants, foreign_key: "participant_id"
has_many :participated_incidents, through: :incident_participants
end
class Incident
2006 Jan 20
1
stack level too deep from has_many / belongs_to relationship
I have the following 3 models (2 models joined by an intermediate):
1. class Exercise < ActiveRecord::Base
2. has_many :routines, :class_name=>''RoutineExercise''
3. end
1. class Routine < ActiveRecord::Base
2. has_many :exercises,
3. :class_name=>''RoutineExercise'',
4. :order=>''position''
5. end
1. class
2006 Jun 23
2
polymorphic challenge
Hello All,
I have a little challenge and I am not sure if this is even possible
I am working on a dating/event site and few functionalities are similar
that I want to centralize them.
We have users which can have
- favorite users
- interest list
- blocked users
All these relations are like;
User <-> Relation <-> User
I was thinking I could have a class called Relation (with a
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 Feb 26
4
Creating objects with has_many :through relationship
Three tables:
users: id
clients: id
admin_contacts: user_id, client_id
class Client
has_many :admin_contacts
has_many :contacts, :through => :admin_contacts, :foreign_key => :user_id,
:class_name => ''User''
end
I added the :contacts for ease of use of grabbing the user objects
associated with the admin_contact.
This all works great, I can grab the Users that
2009 Jul 29
5
[newbie] double relationships in database
I have the following tables
teams
id :string
name :string
and
matches
id:
home_team :team_id
visitor_team :team_id
how can I reflect that kind of relationship in a RoR model?
thanks and keep up the good work.
2008 Apr 09
3
help with model relationship for Product/Bill of Materials
I am struggling to find the best way to set up relationships to
achieve this so that it fits the rails idioms.
I have a table of products and I want to be able to create a bill of
materials for a product..
So a product can either be a single item, or a package consisting of
several other products.
I have created a table:
----
class BomItem < ActiveRecord::Base
belongs_to :product
2006 Apr 24
9
Confusion with expressing many to many relationship
Hi folks, I am in the process of converting an existing non-rails
application to rails, and am not sure what the best approach would be
for specifying the relationship between the two sets of data.
I''ll describe the existing table structures first.
Table 1: Urls
Each url has a unique id and two lists of Phrases, these are currently
setup as varchars with "," delimitation -
2006 Jun 21
6
Sort table by child row property?
I''m building a simple forum system which features a topics and a posts
table. The topic model has a has_many association with the post model,
i.e.:
class Topic < ActiveRecord::Base {
has_many :posts
}
class Post < ActiveRecord:Base {
belongs_to :topic, :dependent => true
}
Now, I wish to sort the topics by the created_at property of the last
post, but I can''t
2006 Jun 03
2
Parent listing children.
My database is set up as Categories > Things associated by category_id
and has_many and belongs_to.
How would I go about listing all the categories and under each Category
is it''s children? Is there an easy rails way to do this - preferably
without using acts as tree? Any help is appreciated - thanks!
--
Posted via http://www.ruby-forum.com/.
2005 Dec 12
2
How to use arbitrary relationships in Activerecord
How can I ask ActiveRecord to make it''s "has_many" code to work on some
arbitrary relationship between two tables? ie neither field is a primary key
The situation is that I am writing a Postfix management application and
one of the tables to manage is the "alias" table. My primary key in the
"mailbox" table is "id", but the alias table is just
2006 Nov 02
4
Still Having Problems With :through When Going To Same Table... Help... please :-(
I am having a problem with doing a :through that goes back to the same table.
The following are my two classes:
>>>>>
class User < ActiveRecord::Base
has_many :spanks
has_many :spanked, :through => :spanks, :source => :spanked_user
has_many :was_spanked_by, :through => :spanks, :source => :user
end
class Spank < ActiveRecord::Base
belongs_to :spanker,