Preface: This is a widely asked question even on SO, and also widely the answers are related to Subclass or actually SuperClass approach (e.g. [1]) Actual answer: On these posts [2], [3] they suggest to use a xml mapping with EntityName parameter. So, mapping with xml you don’t need superclass, just give the EntityName parameter … Read more
Your Status entity must not have properties userId and contentId of type Integer, mapped with @Column. It must have properties user and content of type User and Content, mapped with @OneToOne: public class User { @OneToOne(mappedBy = “user”) private Status status; // … } public class Status { @OneToOne @JoinColumn(name = “frn_user_id”) private User user; … Read more
Annotations are a better choice for a new application, since it makes the application free from XML files. It is also less code and maintenance is easy. It also helps for refactoring the application (with IDE like Eclipse/NetBeans, etc.), which is the problem with XML since you need to change it manually. Answers: No issues, … Read more
The mappedBy attribute is referencing customer while the property is mCustomer, hence the error message. So either change your mapping into: /** The collection of stores. */ @OneToMany(mappedBy = “mCustomer”, cascade = CascadeType.ALL, fetch = FetchType.LAZY) private Collection<Store> stores; Or change the entity property into customer (which is what I would do). The mappedBy reference … Read more
If there’s a combination of columns that makes a row unique, model a primary key class around the combination of columns. If there isn’t, you’re basically out of luck — but you should reexamine the design of the view since it probably doesn’t make sense. There are a couple different approaches: @Entity public class RegionalArticle … Read more
@ManyToMany to self is rather confusing because the way you’d normally model this differs from the “Hibernate” way. Your problem is you’re missing another collection. Think of it this way – if you’re mapping “author”https://stackoverflow.com/”book” as many-to-many, you need “authors” collection on Book and “books” collection on Author. In this case, your “User” entity represents … Read more
You are missing a field annotated with @Id. Each @Entity needs an @Id – this is the primary key in the database. If you don’t want your entity to be persisted in a separate table, but rather be a part of other entities, you can use @Embeddable instead of @Entity. If you want simply a … Read more
Out of the box – no. You can write your own code to detect / register your annotated classes, however. If you’re using Spring, you can extend AnnotationSessionFactoryBean and do something like: @Override protected SessionFactory buildSessionFactory() throws Exception { ArrayList<Class> classes = new ArrayList<Class>(); // the following will detect all classes that are annotated as … Read more
Here is a nice explanation from Object DB. Designates a ManyToOne or OneToOne relationship attribute that provides the mapping for an EmbeddedId primary key, an attribute within an EmbeddedId primary key, or a simple primary key of the parent entity. The value element specifies the attribute within a composite key to which the relationship attribute … Read more
@NotNull is a JSR 303 Bean Validation annotation. It has nothing to do with database constraints itself. As Hibernate is the reference implementation of JSR 303, however, it intelligently picks up on these constraints and translates them into database constraints for you, so you get two for the price of one. @Column(nullable = false) is … Read more