I am using JPA 2 and my problem is about inheritence and overidde Mapping in JPA 2.
I have one Abstract Class [AbstractCompte] and two leafs classes [Compte , CompteTmp].
I want to redefine the Mapping for one Field nrCompte.
nrCompte must be unique in Compte Class .
nrCompte is non unique in CompteTmp class .
I already test putting the #Column in the getter methods of COmpte and CompteTmp and it doesn't work and the result is that nrCompte is always not unique .
#MappedSuperclass
public abstract class AbstractCompte{
#Id
#GeneratedValue
private Long id;
private String nrCompte;
....
....
}
#Entity
public class CompteTmp extends AbstractCompte {
#Column(length=16, unique = false)
public String getNrCompte() {
return super.getNrCompte();
}
}
#Entity
public class Compte extends AbstractCompte {
#Column(length=16, unique = true)
public String getNrCompte() {
return super.getNrCompte();
}
}
Thanks in advance for your help .
JPA offers AttributeOverride, so you can map it like this:
#Entity
#AttributeOverride(name="nrCompte", column=#Column(unique=false))
public class CompteTmp extends AbstractCompte { ... }
#Entity
#AttributeOverride(name="nrCompte", column=#Column(unique=true))
public class Compte extends AbstractCompte { ... }
Related
How can I tell hibernate to ignore a field during schema auto generation?
In this special case: the field is inherited from a parent abstract class, so I cannot just comment it out!
I tried using #Transient, but the field is still autogenerated in the schema.
#MappedSuperclass
public abstract class BaseEntity {
private String someField;
//getter+setter
}
#Entity
public class MyEntity extends BaseEntity {
#Transient //I want to ignore this field during hibernate.ddl.auto
#Override
public String getSomeField() {}
}
Add the Transient annotation in the super class:
#MappedSuperclass
public abstract class BaseEntity {
#Transient
private String someField;
}
#Entity
public class MyEntity extends BaseEntity {
}
I'm trying, but have not been successful so far, using the following classes with Hibernate.
#MappedSuperclass
#Embeddable
public abstract class Foo {
// atributes...
}
#Embeddable
public class Poo extends Foo {
// atributes...
}
#Entity
#Table
public class None {
// atributes...
#Embedded
private Foo foo;
// constructor
public None(Foo foo) {
this.foo = foo;
}
}
// example of save
None none = new None(Poo poo);
save(none);
Hibernate returns: Cannot instantiate abstract class or interface
Is it possible to perform this operation with JPA?
I ran into the same problem.
It seems like #embedable does not work with #DiscriminatorColumn. The only way I could get this to work is to use #DiscriminatorColumn, but treat the #embedable like a separate entity on the same table.
What this means is that the query will likely join the table to itself.
#Entity
#Table(name="tbComputers")
public class Computer{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
public long id;
public String motherboard;
#OneToOne
#JoinColumn(name="id")
public CPU cpu;
}
#Entity
#DiscriminatorColumn(name="cpu_type")
#Table(name="tbComputers")
public abstract class CPU {
#Id
private Long id;
#Column(name = "cpu")
public String name;
public abstract String someProcessorSpecificMethod();
}
#Entity
#DiscriminatorValue("Intel")
public class Intel extends CPU {
#Override
public String someProcessorSpecificMethod() {
return "Intel";
}
}
#Entity
#DiscriminatorValue("AMD")
public class AMD extends CPU {
#Override
public String someProcessorSpecificMethod() {
return "AMD";
}
}
EDIT: After further testing I found that while this works for reading data, it does not for persisting. It will create a separate INSERT. It seems like it is not supported https://hibernate.atlassian.net/browse/HHH-1910. The alternative is to to split the table.
I'm building RESTful service on java using JERSEY and need to implement relationships between entities storing just identifier on another entity not whole. Is there any way to implements it in the hibernate?
I'm using something like this but it is not working.
#Entity
#javax.persistence.Table(name = "manager_user")
public class ManagerUser extends User {
#ManyToOne(targetEntity = ShopAdminUser.class)
private Integer shopAdminUserId;
//...
}
#Entity
#javax.persistence.Table(name = "shop_admin_user")
public class ShopAdminUser extends User {
#Lob
private String contactData;
public String getContactData() {
return contactData;
}
public void setContactData(String contactData) {
this.contactData = contactData;
}
}
#Entity
#Inheritance(strategy= InheritanceType.TABLE_PER_CLASS)
public abstract class User {
#Id
#GeneratedValue(strategy = GenerationType.TABLE)
private Integer id;
//...
}
It will be very comfortable for me to implement this.
I want to use Hibernate. I have a database schema and I would like to write annotations in my code.
I have az A class. It's look like this:
In A.java:
public class A {
public Integer id;
}
In B.java:
#Entity
#Table(name="table_b")
public class B extends A {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
//How can I get that id attribute from the A class?
#Column
public String string;
}
you put the annotation #MappedSuperClass above class A. The field id has to be annotated in clas A not B.
I have a problem, I have two entity Job and JobPK
Job class looks like this sample code :
#Entity
#IdClass(JobPK.class)
#Table(name="JOB")
#Inheritance
#DiscriminatorColumn(name="JOB_TYPE")
public abstract class Job implements Serializable {
#Id
#Column(name="FOLDER_ID")
private BigDecimal folderId;
#Id
#ColumnDefinition(position = 1)
private String name;
#Column(name="JOB_TYPE",insertable=false,updatable=false)
private String jobType;
...
}
and JobPk :
public class JobPK implements Serializable {
private static final long serialVersionUID = -3266336718203527905L;
#Column(name="JOB_TYPE",insertable=false,updatable=false)
private String jobType;
#Id
private String name;
#Id
#Column(name="FOLDER_ID")
private BigDecimal folderId;
......
}
I have two class which extends Job : CalculatingJob and ImportingJob
Now I wont to use :
getEntityManager().find(CalculatingJob.class, new JobPK (BigDecimal.valueOf(folderId),name))
and I have problem because I must fill i JobPK descriminator value field. If I don't do that I've got Null Pointer Exception. Descriminator value is in key by default I think but I don't want put information about descriminator value explicite during JobPk creating. I thought that Entity which extends from Job will fill this field automaticaly. Any Idea to bypass this problem, maybe I can get Annotation #DescriminatorVale from CalculatingJob and then put into constructor JobPk
Thanks for Help
Try this configuration for Hierarchy structure
Job.java
#Table(name = "JOB")
#Inheritance
#IdClass(JobPK.class)
#DiscriminatorColumn(name = "JOB_TYPE", discriminatorType = DiscriminatorType.STRING)
public abstract class Job implements java.io.Serializable {
}
CalculatingJob.java
#Entity
#DiscriminatorValue("CalculatingJob")
public class CalculatingJob extends Job {
}
ImportingJob.java
#Entity
#DiscriminatorValue("ImportingJob")
public class ImportingJob extends Job {
}
JobPK.java
public class JobPK implements Serializable {
}
The discriminator value is entered by hibernate.