We have the following two entities with many-to-many association: @Entity public class Role { ... @ManyToMany @JoinTable( name = "user_has_role", joinColumns = { @JoinColumn( name = "role_fk" ) }, inverseJoinColumns = { @JoinColumn( name = "user_fk" ) } ) private Set<User> userCollection; ... } and @Entity publi...
I have a many to many relationship as follows: Products ProductID Description ProductFeatures ProductFeatureID ProductID FeatureID Features FeatureID Description Any Product can have many Features. I then come along with an iQueryable called "SearchFeatures" which contains two particular Feature objects that I want to search on. I ...
This is a follow up question to this question I asked yesterday. I've tracked down exactly the issue I think is causing me grief and I think I can explain the situation with more clarity. I just can't seem to figure out how to write objects with a many to many relationship to a SQL database using the Entities Framework in a C# ASP.NET M...
There are two entities: @Entity class A { @ManyToMany List<B> bs; } @Entity class B {} I now want to duplicate (clone) an instance of class A. Is there any way with Hibernate to make a shallow copy of the persistent collection bs without having to completely initialize all Bs? In SQL it would be quite easy because you would just ...
Hi, i have the two classes Person and Attribut, in short: @Entity @Indexed @Table(name="persons") public class Person { private int id; private List<Attribute> attributes; @Id @DocumentId @GeneratedValue @Column(name="person_id") public int getId() { return id; } @ManyToMany @JoinTable( name="attribute_all...
Hello, I have three tables: note, user and tag. Following is the diagram of the relationship between those tables: User can have many Notes and Tags, Note can have many Users and Tags, Tag can have many Users and many Notes. I have no problem setting many-to-many relationship between two tables, but can't manage to relate three table...
I want to port a social network to Mongoid. The join table between friends is very large. Is there any way for Mongoid to handle this join table out of the box? I've seen a couple of in-model roll-your-own solutions to it, but nothing the looks efficient. Is there a way to handle this? Or is this a case where I shouldn't be using Mo...
Greetings, I'm having a hard time with the ADO.NET Entity framework. I want to do a relation between 2 existing items, in a Many to Many table. Example: create table A(key int, value varchar(10)); create table B(key int, value varchar(10)); create table A_B(keyA int, keyB int);-- those are FK.. Now I want to do the relation between...
I have a table of events and i want to make groups of them. that is the easy easy // this cascade group still removes the join table but not the products table @ManyToMany(targetEntity=Product.class,fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.REFRESH,CascadeType.MERGE}) @JoinTable(name = "lcw_group_prod...
In a project I am working on, we are using tabs. These tabs have content. Multiple content objects can be on a tab. So we could have a 'car' tab, and that car tab may display a sedan content object, a suv content object and a truck content object. The user could also specify that it contains more or less of these objects and order them h...
From the Django documentation... When you're only dealing with simple many-to-many relationships such as mixing and matching pizzas and toppings, a standard ManyToManyField is all you need. However, sometimes you may need to associate data with the relationship between two models. For example, consider the case of an application...
I have a Person model that has a many-to-many relationship with an Email model and I want to create a factory that lets me generate a first and last name for the person (this is already done) and create an email address that is based off of that person's name. Here is what I have for create a person's name: Factory.sequence :first_name ...
I have an entity that has many-to-many association to itself. If I needed some additional properties (like asked here) the answer would be to use a new intermediate entity. But without them is it bad practice to use direct many-to-many association to the entity itself? ...
Lets say I have a many-to-many relationship: Group table User table group_user table which is a many to many table Given the group name I would like to find all the users that belong to this group. How can I do this with subsonic 3.0? IQueryable<group_user> groupUser= group_user.All(); Is it possible from groupUser to get all use...
I have this working to a degree, but I am looking for some input on how to query for the siblings in a one to many relationship to see if there is a more elegant way of accomplishing this. Consider the following classes class Post < ActiveRecord::Base has_many :post_categories has_many :categories, :through => :post_categories en...
Hi, I was working on a many-to-many model with extra fields and i saw the documentation for extra fields in many to many relations on their exemple, to create a membership they use m2 = Membership.objects.create(person=paul, group=beatles,date_joined=date(1960, 8, 1), invite_reason= "Wanted to form a band.") but that means that they...
Hi! How i can map structure like this into class A{ Map<SomeEnum, B> foo; } where key in foo is representation of role in a_ has _b ? Thanks! ...
I have a Hibernate entity named Menu which has a collection of Groups, each group in turn has a collection of MenuItems. So as an example, a menu can be for a restaurant, groups can be Lunch and Dinner and the menuItems within these can be Pasta, Burger, Salad. The problem I'm having is that once i have created the menu and saved it ...
Using the model-first approach, I made 2 entities: Project and User. A project has multiple Users (involved in the project), and a User has (access to) multiple Projects, so following along with the Tekpub video, I made the many-to-many navigation property using the primary keys of the two entities. I made some test data, and the data ...
I have an application in which I am trying to implement ManyToMany relation between 2 entities using Hibernate as my JPA provider. The example I am trying is an uni-directional one, wherein a Camera can have multiple Lenses and Lense can fit into multiple Cameras. Following is my entity class...(Just pasting the relevant part of it) C...