How to build correctly relations:
Card has an Owner, Owner has a Card.
Card:
- Id
- OwnerId
- Number
Owner:
- Id
- CardId
- Name
And when I'm updating Card's owner (OwnerId) I need automatically update Owner's CardId (remove previously and set CardId to new Owner)
The best way to map a #OneToOne relationship is to use #MapsId.
#Entity(name = "Owner")
public class Owner {
#Id
#GeneratedValue
private Long id;
private String name;
...
//Getters and setters omitted for brevity
}
#Entity(name = "Card")
public class Card {
#Id
private Long id;
private String name;
#OneToOne(fetch = FetchType.LAZY)
#MapsId
private Owner owner;
...
//Getters and setters omitted for brevity
}
I am not sure if I understand your question but identities don't change over the time.
Related
I need help for this case.
I have the following entities (I removed getters/setters/hash/toString for easy reading):
#Entity
public class Company implements Serializable{
#Id
private String id;
}
#Entity
public class Document implements Serializable{
#Id
private String id;
}
#Entity
#IdClass(Inbox.PK.class)
public class Inbox implements Serializable {
#Id
#ManyToOne(fetch = FetchType.LAZY)
private Company company;
#Id
#ManyToOne(fetch = FetchType.LAZY)
private Document document;
#OneToOne(fetch = FetchType.LAZY, mappedBy = "inbox")
private Invoice invoice;
public class PK implements Serializable{
private Company company;
private Document document;
}
}
First question is, should I use Company and Document types in PK class or String and String?
And here ... the headache :
#Entity
#IdClass(Invoice.PK.class)
public class Invoice implements Serializable {
#Id
#OneToOne(fetch = FetchType.LAZY, mappedBy = "invoice")
// #MapsId // ???
#JoinColumn(name = "companyId")//, referencedColumnName = "company")// ???
#JoinColumn(name = "documentId")//, referencedColumnName = "document")// ???
// #PrimaryKeyJoinColumn // ????
private Inbox inbox;
#Data
public static class PK implements Serializable {
// private Inbox inbox; // ???
// private String company,document; // ???
// private String companyId,documentId; // ???
// private String inboxCompanyId,inboxDocumentId; // ???
}
}
The PK of the Invoice Entity is also the FK to Inbox (I would like constraints to be generated), and the PK of Inbox is composed of two Entities (Company and Document).
I prefer to use IdClass rather EmbeddedId.
How could I configure Invoice to have, at the end, (company_id,document_id) as PK AND FK to Inbox?
I saw your question posted in upwork. I think you should use string + string type fields with #Id and #Column annotations in PK class.
My use case is: I have a Product with multi language name. To have at most one name per language a translation should be identified by locale + productId.
My problem is to get it working with a generated productId. This are the entities:
e.g. in oracle i get: "ORA-01400: cannot insert null into ."PRODUCT_NAME"."FOREIGN_ID""
Product:
#Entity
#Data
public class Product {
#Id
#GeneratedValue
private Long id;
#Column(unique = true)
private String articleNumber;
/**
* Localized name of the product.
*/
#OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
#MapKey(name = "nameId.locale")
private Map<Locale, ProductName> names = new HashMap<>();
}
ProductName:
#Entity
#Data
public class ProductName {
#EmbeddedId
private TranslationId nameId;
private String name;
}
TranslationId:
#Embeddable
#Data
public class TranslationId implements Serializable {
private static final long serialVersionUID = 3709634245257481449L;
#Convert(converter = LocaleConverter.class)
private Locale locale;
private Long foreignId; //<-- this is null, should reference product
}
Is there a way to get this working without having to save the product first without the name? Without a generated id it is working of course - i just set same id for both.
I would like to re-use the translation id for other translated fields of other entities.
I have 3 entities named Student, Course, and StudentCourse as follows
#Entity
#Table(name = "student")
public class Student {
#Id
#GeneratedValue
private Integer id;
private String fullName;
}
#Entity
#Table(name = "course")
public class Course {
#Id
#GeneratedValue
private Integer id;
private String courseName;
}
#Entity
#Table(name = "student_course")
public class StudeCourse {
#Id
#GeneratedValue
private Integer studentId;
private Integer courseId;
private String extraColumn;
}
Restrictions: There are a couple of restrictions
One student can have only one course or no course at all
An extra entity (StudentCourse) is required to hold the relation with primary key as studentId only
StudentCourse is required and hence cannot be skipped
Get Student with Course entity if there is one registered
Help required in some magical code to retrieve Course of Student if there is one assigned.
#Entity
#Table(name = "student")
public class Student {
#Id
#GeneratedValue
private Integer id;
private String fullName;
// this is not correct code but just what I want
#JoinEntity(entity=StudentCourse, column="courseId")
private Course course;
}
StudentCourse is required and hence cannot be skipped
Ok, lets work with that.
One student can have only one course or no course at all
Implies that there is a #OneToOne relationship between Student and StudentCourse.
With the given information, the following entity model will work:
#Entity
#Table(name = "student")
public class Student {
#Column(name = "id")
#Id
#GeneratedValue
private Integer id;
#Column(name = "full_name")
private String full_name;
#OneToOne
#PrimaryKeyJoinColumn
private StudentCourse studentCourse;
}
#Entity
#Table(name = "student_course")
public class StudentCourse {
#Column(name = "id")
#Id
#GeneratedValue
private Integer id;
#JoinColumn(name = "id", nullable = false, updatable = false)
#MapsId
#OneToOne
private Student student;
#JoinColumn(name = "course_id")
#ManyToOne
private Course course;
...
}
A quick review:
#OneToOne on the Student.studentCourse field signifies that for every Student, there can be only one StudentCourse, and no more.
#PrimaryKeyJoinColumn on the Student.studentCourse field signifies that the value of the primary key column for Student should be used as the foreign key for the related entity, that is, StudentCourse.
#OneToOne on the StudentCourse.student field signifies that for every StudentCourse, there can be only one Student.
#MapsId on the StudentCourse.student field signifies that the primary key column for StudentCourse should be used as the join column for the association.
To check if a student has a course assigned, simply check if student.getStudentCourse() != null and then get the assigned course as student.getStudentCourse().getCourse().
I have the following two entities (Contact and Participation, linked by a ManyToMany relation) :
#Entity
public class Contact {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#Column(nullable=false)
private String firstName;
#Column(nullable=false)
private String lastName;
#ManyToOne
private Company company;
#ManyToMany(fetch=FetchType.EAGER)
private List<Participation> participations;
}
#Entity
public class Participation {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#ManyToOne
private Company company;
private Status status;
}
I can't figure out how to get Contacts who have a specific Participation in their list. Should I look via Contacts with a specific JPA repository method (findBy...) ? Or would i have to look via the table which was created with both Contact and Participation IDs (ManyToMany) ?
Thanks!
I am trying to migrate a Seam 2 app to CDI and use PicketLink for security. After all the reading and researching, it seems like all the examples are having one to one mapping between PicketLink model and the backend entity. e.g. Account to AccountEntity, Partition to PartitionEntity. Since I already have entities in place representing identity model, I am stuck on trying to map them to PicketLink. Here is what I have:
#MappedSuperClass
public class ModelEntityBase implement Serializable {
#Id #Generated
Long id;
Date creationDate;
}
#Entity
public Account extends ModelEntityBase {
String username;
String passwordHash;
#OneToOne(mappedBy = "account")
Person person;
}
#Entity
public Person extends ModelEntityBase {
String name;
String email;
#OneToOne
#JoinColumn(name = "account_id")
Account account;
}
Two entities (plus a super class) representing a single identity model in PicketLink, e.g. stereo type User.
Based on this why IdentityType id is String not Long, I tried to add a new Entity in:
#Entity
#IdentityManaged(BaseIdentityType.class);
public class IdentityTypeEntity implement Serializble {
#Id #Identifier
private String id;
#OneToOne(optional = false, mappedBy = "identityType")
#OwnerReference
private Account account;
#IdentityClass
private String typeName;
#ManyToOne #OwnerReference
private PartitionEntity partition;
}
I've tried a few different ways with the annotation and model classes. But when using IdentityManager.add(myUserModel), I just can't get it to populate all the entities. Is this even possible?
Got help from Pedro (PicketLink Dev). Post the answer here to help others.
This is the model class I ended up using.
#IdentityStereotype(USER)
public class User extends AbstractAttributedType implements Account {
#AttributeProperty
private Account accountEntity;
#AttributeProperty
#StereotypeProperty(IDENTITY_USER_NAME)
#Unique
private String username;
#AttributeProperty
private boolean enabled;
#AttributeProperty
private Date createdDate;
#AttributeProperty
private Date expiryDate;
#AttributeProperty
private Partition partition;
// getter and setter omitted
}
And created a new entity to map to this model:
public class IdentityTypeEntity implements Serializable {
#Id
#Identifier
private String id;
#OneToOne(optional = false, mappedBy = "identityType",
cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#AttributeValue
// #NotNull
private HAccount accountEntity;
#IdentityClass
private String typeName;
#ManyToOne
#OwnerReference
private PartitionEntity partition;
#AttributeValue
private String username;
#AttributeValue
// #Transient
private boolean enabled;
#AttributeValue
private Date createdDate;
#AttributeValue
private Date expiryDate;
}
PL can map property with #AttributeProperty to entity property with #AttributeValue. But it can only map to one entity. Therefore there is no way to map, say User and its properties over to Account and Person. But you can have the entity (in my case accountEntity) in the model. I also have to duplicate a few fields in the new IdentityTypeEntity and my existing Account entity (username, eanbled, createdDate) because PL requires these. Use a #PrePersist and similar to sync them.