associations

LINQ: Associations not functioning correctly for use with innerjoins

Hi there, Can anyone help, I have been using linq2sql with great success using my associations (foreign keys) to provide inner joins etc... for example this, works great, the color is stored in a table called Color which has association so i pick it up via Color.Description - Excellent. Same for StructureType its actually an associati...

LINQ: Using a pivot table in linq

Hi there, Can anyone help? I have the following structure using associations, and as you can see v.StructureType.Description works great as its a 1 to 1 association, but i need to get in my example below v.StructureGroup.StructureGroupTariffs.Tariff.Price but StructureGroupTariffs is a Pivot table to interlink the StructureGroup and Ta...

Mapping integers to booleans in Objective-C

In Objective-C I need to associate a mutable collection integers (monotonic, non-contiguous, could get fairly large) to boolean values. The obvious way is just to have an NSDictionary w/ NSNumbers as keys and values. Is there a better way that doesn't involve so much object creation? I'm really not trying to pre-optimize so much as lea...

has_many through self referential association

I want to (as an example) create a has_many association to all posts by friends of a person, something like has_many :remote_posts to give me something like person > friends > person > posts. ..here is how I would go about it script/generate model post title:string person_id:integer script/generate model friendship person_id:integer f...

Updating a 2-dimensional form

Hey guys. I'm new-ish to rails development and have hit a bit of a wall. The application I'm working on is a scheduling solution that requires updating a join model, but not in a simple 1:1 sort of way. The app is laid out as follows: class Route < ActiveRecord::Base has_many :markers, :foreign_key => 'source_id' has_many :schedu...

Auditing and model lifecycle management for instances and their associations?

I am trying to write an application to track legal case requests. The main model is Case, which has_many Subjects, Keywords, Notes, and Evidences (which, in turn, has_many CustodyLogs). Since the application is legal-related, there are some requirements that are out of the ordinary: CRUD operations must be logged, including what the ...

Linq To Sql Associations

So I've created a dbml in my project, which has three tables: Elements, ElementImages and Images. Every Element record could have multiple ElementImage records and each of those ElementImage records should have one Image record. The primary and foreign keys are all set up correctly and the associations are defined correctly as well. ...

Multiple column foreign keys / associations in ActiveRecord/Rails

I have badges (sorta like StackOverflow). Some of them can be attached to badgeable things (e.g. a badge for >X comments on a post is attached to the post). Almost all come in multiple levels (e.g. >20, >100, >200), and you can only have one level per badgeable x badge type (= badgeset_id). To make it easier to enforce the one-level-p...

Entity Framework - Association Set

I am converting a project from another ORM to Entity Framework. I have a table where all 3 fields are foreign keys. So this table has been automatically mapped as an Association Set. In the previous ORM I could still work with this table as an entity - writing linq statements against it, adding and deleting objects etc. Is it possibl...

What is the difference between association and dependancy relationship?

What's the difference between Association and Dependency? Aren't they both the same thing? as if class A is associated with B then Class A is dependent on B ie. there's a dependency between A and B. ...

mass_assign, virtuell attributes, nested tables, attr_accessible, accepts_nested_attributes_for, action=>update

Hello, I don't understand the workaround with the virtuell attribute. Form Railsforum by Duplex URL: http://railsforum.com/viewtopic.php?pid=110698#p110698 His solution: > def type_helper self.type end def type_helper=(type) self.type = type end < My application is based on RailsCast part 73,74,75 complex_forms I have two models...

Rails Filter records of child model based upon the parent model attribute

Following are the 1-to-M models: class FotoGossip < ActiveRecord::Base has_many :uploads attr_accessible :published_at, ... end class Upload < ActiveRecord::Base belongs_to :foto_gossip end Now I want the Uploads.all with the condition :published_at NOT NULL of the corresponding upload's parent model? ...

dropdown select in cakePHP

Hello, I am using CakePHP 1.2. I have a person model that hasMany 'Document'. When I edit a document, the select box for the owning person appears (echo $form->input('person') where person has been defined in the documents_controller like this: $allPeople = $this->Document->Person->find('list', array('fields' => array('first_name')))...

[Rails] Can a model "belongs_to" either/or more than one model?

Apologies if this is a slightly noob question, but looking to clarify my thoughts on this. I have a model that can EITHER belong to one model, or another. For example: Let's say I have a Team model and I have a Member model, and both of those models can have one BankAccount. class Team has_many :members has_one :bank_account end c...

NHibernate - access the ID of an associated object without lazy loading the whole object

I have two associated business objects - A and B. the association is (A->B)many-to-one, with B.Id a foreign key in A (so A has A.B_id in the DB). I'm using lazy=true and solved most of my problems, however in A's ToString I want to print also A.B.Id, which I should have without further trips to the DB. but accessing A.B activates the pr...

hibernate @DiscriminatorValue does not apply to associations

I have the following inheritance hierarchy. @Entity @Table(FRUIT) @Inheritance(strategy=InheritanceType.SINGLE_TABLE) @DiscriminatorColum(name="FRUIT_TYPE",discriminatorType=STRING) public class Fruit { .. @Id private FruitId id; ... } @DiscriminatorValue("APPLE") public class Apple extends Fruit { ... @ManyToOne private FruitBowl bowl...

How could I be sure that choosing HABTM over has_many :through is more suitable?

I have been hearing a lot of buzz around has_many :through(HMT) vs has_and_belongs_to_many (HABTM). This post covers most of its benefits. Okay, HMT sure has some real good benefits over HABTM. However, what I wanted to know that when should I know that I should be using HMT over HABTM? Often I am in a situation where I believe that plai...

RoR: "belongs_to_many"? Association headache...

I can't seem to wrap my head around this, so I thought I'd post and see if anyone could help me out (please pardon the question if it's insultingly simple: it's complicated to me right now!) I have these models: order service customer I think they speak for themselves: a service is what the customer buys when they place an order. O...

Associate a File To a Application

Hello, I'm building two programs, a text editor and a zipper, but in this two programs I want to associate a file type to they, but how can I do this? Thanks. ...

Conditions in associated models using Model->find() (CakePHP)

Hi, I am having some issues with CakePHP's find() method and conditions in 'deeper' model associations. There are some of these around but I could not find an answer to this so far. My model associations are User hasMany Post hasMany Comment hasMany Vote and Vote belongsTo Comment belongsTo Post belongsTo User respectively. The belongsT...