similar to: table that have many-to-may relationship to itself

Displaying 20 results from an estimated 1000 matches similar to: "table that have many-to-may relationship to itself"

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 May 28
3
Association of table to itself
I''m curious what would be the best way to represent people and whether the person has someone marked as their friend. Here are my thoughts so far: People table - id - name Relationships table - person_id - friend_id Now my problem is I don''t know how to set up these associations (if this is even correct). Friend_id would be an id to someone else from the people table.
2006 Aug 02
2
Self-Referential has_many :through
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
2006 Feb 21
7
Self-referencial habtm relationship
Heyo! I am setting up a self-referencial habtm relationship with the users of my app. I am using Chad Fowler''s "Rails Recipes" to get me started, and everything works great with the join table "people_friends". I add friends by doing somebody.friends << somebodyelse. However, with my app, there is an approval process so my join table has columns person_id,
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 02
0
Self-referential MtoM implementation
ok, guys i have followed the self referential recipe from the book it works perfect but now i have some doubts, at the end the model are modified to force the user beign added as a friend that add too who are adding him so how i can make that the full relationship doesn?t be complete until the friend beign added approves it(talking in the implementation of the code of course)? by the way,
2006 Mar 31
6
Adding objects to a :through association
So I''m one of those nasty people building a self-referential habtm-like Association using the funky new :through stuff. This is about users having friends, so here''s my user.rb: class User < ActiveRecord::Base has_many :friendships, :foreign_key => ''user_id'' has_many :friends, :through => :friendships, :source => :friend end And here''s
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,
2008 Aug 29
3
Many to Many Relationship with One Model
Hey everyone, I''m working on allow users to follow other users in my app so they can receive updates to what all their friends are doing (like Facebook/ Twitter). I''m wondering on how the relationship would be for the model. Sounds like a HABTM type of association, but how would I go about doing it for only one model? Thanks, Tony
2006 Jan 24
3
Merging two heavily referenced records into one
Here''s the situation: I have a "people" table whose "id" column serves as a foreign key to several other tables (authorships, editorships, members, users, etc.). Every now and then I will find two distinct records in the "people" table that represent the same human being. They generally differ by small differences in spelling but should really be the
2006 Jul 17
14
REST Relationship Models
I''m trying to figure out an elegant way to do this: I have the following three tables: people, employer, employees And consequently the following three models: class Person < ActiveRecord::Base end class Employer < ActiveRecord::Base has_many :employees end class Employee < ActiveRecord::Base belongs_to :person belongs_to :employer end I want to be able to say:
2006 Jan 06
2
Re: Some advice on DB modeling
I have more or less the same problem. I''m trying to build a system where users can enter their friends. But the solutions seems not to work for me. I used same sql: CREATE TABLE `friends` ( `user_id` int(11) NOT NULL default ''0'', `friend_id` int(11) NOT NULL default ''0'', KEY `user_id` (`user_id`), KEY `friend_id` (`friend_id`),
2009 Feb 27
4
Optimize for loop / find last record for each person
I want to find the last record for each person_id in a data frame (from a SQL database) ordered by date. Is there a better way than this for loop? for (i in 2:length(history[,1])) { if (history[i, "person_id"] == history[i - 1, "person_id"]) history[i, "order"] = history[i - 1, "order"] + 1 # same person else history[i,
2006 Aug 02
2
many-to-one relationship, do I need a second table?
Ok, to keep things short. Im wondering if I need a secondary relationship table to handle my many-to-one relationships. Here is an example of what I''ve written down. For instance say I want to find all of the people in a given location. class Location < AR:Base has_many :people end class Person < AR:Base belongs_to :location end My SQL tables look like: CREATE TABLE
2007 May 16
5
drop a letter
hello, how can I do to drop C from this character "C325" ? _____________________________________________________________________________ [[alternative HTML version deleted]]
2006 Jan 09
3
Design Question
I am sure some of you can give me an insight into this. This is more towards the database design for the scenario below: Say for example, I have a person table and this person can have different address types. One could be Home and the other could be say Office. Should be model this Table people id fname lname Table addresses id person_id addr1 addr2 .... or Table people id fname lname
2006 Mar 15
1
Through method problems with custom foreign_keys
A person has a many company_branches and A company_branch has many people. This join is represented using a "contacts" table. I am using a legacy schema so i am forced into using non-standard rails primary keys. I am using the new through relationship in rails 1.1. p=Person.find(1) b=p.company_branches # gives this error: ActiveRecord::StatementInvalid: OCIError: ORA-00904:
2006 May 26
3
Breakdowns in has_many abstraction
I discovered an interesting aspect of has_many behavior that I''m struggling to work around. I''m not sure if I''m doing something wrong, or if it''s a legitimate bug, or if it''s an inherent part of Rails that I just have to learn to deal with. It boils down to these two problems: - changes in collection objects (i.e. models that belong_to a container
2006 Apr 17
1
database design Q
I am in the middle of setting up mysql database for my RoR application. and here is some questions in my mind hope you can help. 1. this is a photoblog story telling like system, where people can creat their own groups the database tables are: people, groups, articls, pictures People to Groups are many-to-many relationships People to Articles are one-to-many Group to Articles are one-to-many
2006 Mar 25
0
Self-Referential Many-To-Many relationships where the relationship itself has data.
Trying to model a bunch of users that have friends that are other users. clearly a job for has_and_belongs_to_many, but the trick is, they have ratings for their friends. I have gone through the Rails Recipes book, and it seems like I''m trying to combine the self-referential many-to-many recipe (12) and the many to many relationships where the relationship itself has data recipe (16). So