one-to-many

I'm using EF5 code first in a simple test application at the moment to test various functions. I have defined an 'identifying relationship' between two entities which represent a one-to-many link. Here I define a PhotoCollection that has many child Photo entities; public class PhotoCollection { public int Id { get; set; } public virtual ISet<Photo> Photos { get; private set; } public PhotoCollection() { Photos = new HashSet<Photo>(); } } public class Photo { [Key, ForeignKey("Parent"), Column(Order = 1)] public int PhotoCollectionId { get; set; } [Key, Column(Order = 2)] public int PhotoId {

I've got some problem with hibernate @OneToMany mapping. It goes like here @Entity @Table(name = "albums") @SequenceGenerator(name = "ALBUMS_SEQ", sequenceName = "albums_seq", allocationSize = 1) public class AlbumDs { @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "ALBUMS_SEQ") private Integer id; private Integer ownerId; private String name; private String description; private Date created; @OneToMany(cascade = CascadeType.ALL) @JoinColumn(name = "albumId", insertable = true, updatable = true) private Set<UserAlbumDs> users = new HashSet<UserAlbumDs>(); public Integer

I have two entities: @Entity public class File ....... @Id @GeneratedValue(strategy=GenerationType.AUTO) private int id; @OneToMany(fetch=FetchType.LAZY, mappedBy="file", cascade=CascadeType.ALL) private List<Tag> tags; ....... OTHER PROPERTIES ....... @Entity public class Tag ....... @Id @GeneratedValue(strategy=GenerationType.AUTO) private int id; @ManyToOne @JoinColumn(name="file_id") private File file; @Column private String tag; ....... OTHER PROPERTIES ....... I am trying to insert into File (and subsequently Tag) by doing the following: File file = new File(); Tag tag = new Tag(); tag

There is the possibility to disable the @OneToMany relationship join table with the @JoinColumn annotation. The default is a join table. What are the advantages and disadvantages for a production system for example? When should I use a join table and when not? Thank you. By default @OneToMany will create a join table only if you'll use unidirectional relationship . In other words, if you have Employee and Project entities and the Employee entity is defined as follows (assume there is no orm.xml entries for these entities) : @Entity public class Employee { // ... @OneToMany Set<Project>

I have a form to create a new entity. That entity has a collection of other entities that are also entered in that form. I want to use the validation options of the entity in the collection to validate those entities but it does not work. The validation rules of the "main" entity (Person) are checked, but the validation rules of the entities in the addressList collection (Address) are not checked. When I input invalid information in the fields, the submitted form is successfully validated. In this example, the annotation for street is not used on validation. class Person { ... /** * @ORM

Problem I would like to start by saying that I realize the database structure is atrocious, but I cannot change it at this point in time. That being said, I have the need to create a one-to-many, bi-directional relationship in Hibernate (4.2.1) which involves no primary keys (only a unique key on the "parent" side of the relationship) and no join tables. The foreign key representing this relationship is a backpointer from the "child" to the "parent" (see below). I have searched and tried various different annotation configurations with no luck. Is what I'm asking for possible? Database GLOBAL