eager-loading

I'll give the most basic example that I can think of for the purpose of clarity. Lets say that I have two entities of the following form: public class Student { public int Id {get;set} public string FullName {get;set;} public virtual ICollection<Course> Courses {get;set;} } public class Courses { public int Id {get;set;} public string FullName {get;set;} public virtual ICollection<Student> Students {get;set;} } Those two entities map to three tables, the third one being a table for the joins. When I query the Students like this var allStudents = context.Students; and then traverse the results

I'm using Symfony2 with Doctrine2 (latest versions) and have this relation defined: /** * @ORM\OneToMany(targetEntity="Field", mappedBy="event", fetch="EAGER") * @ORM\OrderBy({"name" = "ASC"}) */ protected $fields; The other side of the relation is defined as: /** * @ORM\ManyToOne(targetEntity="Event", inversedBy="fields", fetch="EAGER") * @ORM\JoinColumn(nullable=false, onDelete="CASCADE") */ protected $event; When doing a "fetchOnyById", Doctrine runs 2 queries. 1 to fetch the object itself and 1 for the related fields. I would expect this to be a join, but it isn't. When done in the

As we all know that it is recommended to use annotations from javax.enterprise.context instead of javax.faces.bean as they are getting deprecated. And we all found ManagedBeans with eager="true" annotated with @ApplicationScoped from javax.faces.bean and having a @PostConstruct method are very useful to do web application initialization e.g: read properties from file system, initialize database connections, etc... Example : import javax.faces.bean.ApplicationScoped; import javax.faces.bean.ManagedBean; import javax.annotation.PostConstruct; @ApplicationScoped @ManagedBean(eager=true) public

I've got this really basic table structure: dbo.tblCategory dbo.tblQuestion (many to one relationship to tblCategory) dbo.tblAnswer (many to one relationship to tblQuestion) So basically, what I'm trying to do is when I load a category, I want to also load all Questions, and all Answers. Now, I've been able to do this using the following code: public tblCategory Retrieve(int id) { using (var entities = Context) { var dto = (from t in entities.tblCategory.Include("tblQuestion") .Include("tblQuestion.tblAnswers") where t.Id == id select t).FirstOrDefault(); return entities.DetachObjectGraph(dto)

Loading related object in MVC can be pretty confusing. There are lots of terms you need to be aware of and learn if you really want to know what you're doing when writing your entity model classes and controllers. A couple of questions that I've had for a very long time are: How does the virtual keyword work and when should I use it? And how does the Include extension method work and when should I use it? Here's what I'm talking about; virtual keyword: using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace LazyLoading.Models { public class Brand { public

I have two tables, say "users" and "users_actions", where "users_actions" has an hasMany relation with users: users id | name | surname | email... actions id | id_action | id_user | log | created_at Model Users.php class Users { public function action() { return $this->hasMany('Action', 'user_id')->orderBy('created_at', 'desc'); } } Now, I want to retrieve a list of all users with their LAST action . I saw that doing Users::with('action')->get(); can easily give me the last action by simply fetching only the first result of the relation: foreach ($users as $user) { echo $user->action[0]-