joined-subclass | 易学教程

Avoiding outer joins across tables when using joined inheritance with Spring Data JPA

阅读更多关于 Avoiding outer joins across tables when using joined inheritance with Spring Data JPA

问题 Consider the following classes in a Spring Data JPA (+ Hibernate) application: @Entity @Inheritance(strategy = InheritanceType.JOINED) @Table(name = "person") public class Person { } @Entity @Table(name = "customer") public class Customer extends Person { } @Entity @Table(name = "employee") public class Employee extends Person { } @Entity @Table(name = "manager") public class Manager extends Employee { } public interface IPersonRepository extends JpaRepository<Person, Long> { } public

Java Subclass $

阅读更多关于 Java Subclass $

问题 I am new to Java and might be asking a basic question which might sound silly to some. After I compile my Main Java class most of the subclasses are displayed as $ in the folder. I copy the complied classes and put it on another location to execute. Everytime I make make a change to the main class or one of the sub classes do I need to copy all the associated subclasses? or just copying the changed ones will do? Thanks. Nick 回答1: Is this about subclassing ( class Y extends X {} ), or nested

jpa how to create new entity with same id as parent entity (JOINED Inheritance)

阅读更多关于 jpa how to create new entity with same id as parent entity (JOINED Inheritance)

问题 my question is very similar to Changing the type of an entity preserving its ID, but instead i´m using InheritanceType.JOINED instead of Table_per_class. This means i don´t to change any table, just to create a new subclass, with the same id as the superclass. To summarize, I have a Person class and a Doctor, which extends Person and has the same id of it. I need to retrieve a Person from the database and make it a Doctor, preserving all the data from the Person entity, but creating some

NHibernate Caching Objects Based on Parent Class's ID

阅读更多关于 NHibernate Caching Objects Based on Parent Class's ID

问题 I have the following definitions for the Animal and Dog types. Note that the ID for the object is the AnimalID: <class name="Animal" table="Animals"> <id name="Id" type="System.Int32" column="AnimalID"> <generator class="identity" /> </id> <property name="IsBig" column="IsBig" type="System.Bool" not-null="true" /> </class> <joined-subclass name="Dog" table="Dogs" extends="Animal"> <key column="AnimalID" /> <property name="OwnerID" column="OwnerID" type="System.Int32" non-null="true" />

how to map a one-to-many collection to a joined subclass when key is in the parent class

阅读更多关于 how to map a one-to-many collection to a joined subclass when key is in the parent class

问题 I'd like to map a one to many collection to a subclass but the key of the collection is an attribute of the parent class. Currently i'm mapping AbstractFoo Foo and Bar class like this : <class name="AbstractFoo" abstract="true" table="abstractFoo"> <id name="_id" column="foo_pk"> <generator class="native" /> </id> <many-to-one name="_bar" column="bar_fk"> </many-to-one> <joined-subclass name="Foo" table="foo"> <key column="abstractFoo_fk" /> <property name="_type" column="type" /> </joined

Play Framework 2 Ebean and InheritanceType as JOINED

阅读更多关于 Play Framework 2 Ebean and InheritanceType as JOINED

问题 After some research on Google, I haven't found anyone who has my problem that's why I'm posting it here. In my application I have three entities : User (abstract), Customer, Agency. Customer and Agency extends User. Here is the code of User : @Entity @Inheritance(strategy = InheritanceType.JOINED) public abstract class User extends AbstractModel { @Column(unique = true) @NotNull @Email public String email; @NotNull public String password; } The problem is that the generated schema creates

how to map a one-to-many collection to a joined subclass when key is in the parent class

阅读更多关于 how to map a one-to-many collection to a joined subclass when key is in the parent class

I'd like to map a one to many collection to a subclass but the key of the collection is an attribute of the parent class. Currently i'm mapping AbstractFoo Foo and Bar class like this : <class name="AbstractFoo" abstract="true" table="abstractFoo"> <id name="_id" column="foo_pk"> <generator class="native" /> </id> <many-to-one name="_bar" column="bar_fk"> </many-to-one> <joined-subclass name="Foo" table="foo"> <key column="abstractFoo_fk" /> <property name="_type" column="type" /> </joined-subclass> </class> <class name="Bar" table="bar"> <map name="_foos" inverse="true"> <key column="bar_fk"/