eager-loading

why is this rails association loading individually after an eager load?

I'm trying to avoid the N+1 queries problem with eager loading, but it's not working. The associated models are still being loaded individually. Here are the relevant ActiveRecords and their relationships: class Player < ActiveRecord::Base has_one :tableau end Class Tableau < ActiveRecord::Base belongs_to :player has_many :table...

eager loading association on a subclass

I have the following (simplified) class hierarchy: def Parent < ActiveRecord::Base end def Child < Parent belongs_to :other end def Other < ActiveRecord::Base end I want to get all Parent objects and -if they are Child objects- have them eager load the :other association. So I had hoped I could do: Parent.find(:all, :include => [:o...

Rails Eager Loading Question Find(:all, :include => [:model])

Hello, I have a Topic and a Project model. I have a Many-to-many ass between them (HABTM one). In the Topic's Index Page, I want to display the number of projects that each topic have. So I have @topics = Topic.all(:include => [:projects]) In my controller, and so far so good. The problem is that the Project Model is so big that the ...

Eager loading a tree in NHibernate

I have a problem trying to load a tree, this is my case, I have an entity associated with itself (Hierarchic) with n levels; the question is, Can I load eagerly the entire tree using ICriteria or HQL? Thanks in advance for any help. Ariel ...

How to eager load in WCF Ria Services/Linq2SQLDomainModel

I have a databound grid at my view (XAML) and the Itemsource points to a ReportsCollection. The Reports entity has three primitives and some complex types. These three are shown as expected at datagrid. Additionally the Reports entity has a property of type Store. When loading Reports via GetReports domain method, I quickly figure out th...

What is the Include(..) method not getting found, on my IObjectSet object, in this Entity Framework code?

Hi folks, i'm trying to eager load some child entity, and when I try to add the Include() method, i'm getting a compiler error (ie. it can't find it). er ... can anyone help me out on this one, please? ...

Is it possible to configure NHibernate at runtime setting the loading-technique (eager/lazy) for a collection

Ya is this possible :) ? ...

Using Include() with inherited entities problem

In EF eager loading related entities is easy. But I'm having difficulties including inherited entities when loading data using table-per-type model. This is my model: Entities: ArticleBase (base article entity) ArticleSpecial (inherited from ArticleBase) UserBase (base user entity) UserSpecial (inherited from UserBase) Image R...

HIbernate FetchMode Join

I have a Parent class with a List of children. I would like to load the Parent by something other than the id e.g. by name...I am using criteria.setFetchMode("children",FetchMode.JOIN); and criteria.add(Restrictions.eq("name", name)) to eagerly load all the data for the parent with a unique name. Problem is I get back thousands of result...

Ruby on Rails: Once you've eager loaded an association that has conditions, how can you get at it without touching the database again?

Imagine a simple case like this: class Book has_many :chapters end Let's say in my controller I do something like this: book = Book.find(:first, :include => :chapters, :conditions => ['chapters.title = ?', "In the beginning"] Now let's say I want to display the chapter. How can I address the c...

Ruby on Rails: :include on a polymorphic association with submodels

When working with a polymorphic association, is it possible to run an include on submodels that are only present in some types? Example: class Container belongs_to :contents, :polymorphic => true end class Food has_one :container belongs_to :expiration end class Things has_one :container end In the view I'm going to want to d...

Eager loading for globalize2 translations

Hi, i have 2 models - Issue and Answers (issue has many answers) and both have translations with globalize2. Every time i attempting to load Issue with answers via @issue = Issue.find(params[:id]) @answers = @issue.answers causes loading of translations for each Answer (1 sql query per Answer). How can i optimize it? ...

How to eager load sibling data using LINQ to SQL?

The goal is to issue the fewest queries to SQL Server using LINQ to SQL without using anonymous types. The return type for the method will need to be IList<Child1>. The relationships are as follows: Parent Child1 Child2 Grandchild1 Parent > Child1 is a one-to-many relationship Child1 > Grandchild1 is a one-to...

Eager-loading association count with Arel (Rails 3)

Simple task: given that an article has many comments, be able to display in a long list of articles how many comments each article has. I'm trying to work out how to preload this data with Arel. The "Complex Aggregations" section of the README file seems to discuss that type of situation, but it doesn't exactly offer sample code, nor do...

Entity Framework in n-layered application - Lazy loading vs. Eager loading patterns

Hi all. This questions doesn't let me sleep as it's since one year I'm trying to find a solution but... still nothing happened in my mind. Probably you can help me, because I think this is a very common issue. I've a n-layered application: presentation layer, business logic layer, model layer. Suppose for simplicity that my application ...

Problem with eager load polymorphic associations using Linq and NHibernate

Is it possible to eagerly load polymorphic association using Linq and NH? For example: Company is base class, Department is inherited from Company, and Company has association Employees to the User (one-to-many) and also association to the Country (many-to-one). Here is mapping part related to inherited class (without User and Country c...

NHibernate: References still being eagerly selected after specifying AddJoin

I have a query which is something like this: Session.CreateSQLQuery( @"SELECT f.*, b.*, z.* FROM Foo f LEFT OUTER JOIN Bar b ON b.Id = f.BarId LEFT OUTER JOIN Zar z ON z.Id = b.ZarId" ) .AddEntity("f", typeof(Foo)) .AddJoin("b", "f.BarId") .AddJoin("z", "b.ZarId") .List<Foo>(); The problem is that I ...

Eager load this rails association

Hi, I have rails app which has a list of users. I have different relations between users, for example worked with, friend, preferred. When listing the users i have to decide if the current user can add a specific user to his friends. -if current_user.can_request_friendship_with(user) =add_to_friends(user) -else =re...

Rails - eager load the number of associated records, but not the record themselves.

I have a page that's taking ages to render out. Half of the time (3 seconds) is spent on a .find call which has a bunch of eager-loaded associations. All i actually need is the number of associated records in each case, to display in a table: i don't need the actual records themselves. Is there a way to just eager load the count? Her...

LINQ-to-SQL eagerly load entire object graph

I have a need to load an entire LINQ-to-SQL object graph from a certain point downwards, loading all child collections and the objects within them etc. This is going to be used to dump out the object structure and data to XML. Is there a way to do this without generating a large hard coded set of DataLoadOptions to 'shape' my data? ...