Im trying to create to domain objects with a OneToOne relationship. A is the parent and B is the child.
I tried many different ways to cascade deletions from A to B but when i look a the database creation, it doesnt set up ON DELETE CASCADE.
Can someone see what im doing wrong
A:
#Entity
#Table(name = "financeaccountcurrencymapping")
public class FinanceAccountCurrencyMapping implements Serializable {
#Id
#GeneratedValue
private long id;
#OneToOne(cascade = CascadeType.ALL, optional = false, orphanRemoval = true, mappedBy = "financeAccountCurrencyMapping")
private FinanceAccount financeAccount;
I know that either CascadeType.ALL or orphanRemoval should do the trick, but they dont.
B:
#Entity
#Table(name = "financeaccount")
public class FinanceAccount implements Serializable {
#OneToOne(optional = true)
private FinanceAccountCurrencyMapping financeAccountCurrencyMapping;
Can someone see why it doesnt cascade deletions?
I solved it, but not with JPA
i set #OnDelete(action = OnDeleteAction.CASCADE) on the child
Related
As in the title, when performing the update operation, the previous child loses the reference to the parent.
Parent side
#OneToMany(cascade =CascadeType.ALL)
#JoinColumn(name = "individual_id")
private List<ContactMedium> contactMedium;
Children side
#Entity
#Table(name = "contactMedium")
#Data
#AllArgsConstructor
#NoArgsConstructor
public class ContactMedium
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id ;
#ManyToOne
private Individual individual;
Patch operation
public Individual patch(Individual individual, Long id) {
Individual objectToSave = individual;
objectToSave.setId(id);
return individualRepository.save(objectToSave);
}
When updating, the previous property loses references to the child. How can I prevent this?
Your mappings seems wrong. Ideally they should be as below:
#Entity
#Table(name = "contactMedium")
#Data
#AllArgsConstructor
#NoArgsConstructor
public class ContactMedium
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id ;
#ManyToOne
#JoinColumn
private Individual individual;
and
#OneToMany(mappedBy = "individual", cascade = CascadeType.ALL)
private List<ContactMedium> contactMedium;
You need to save the ContactMedium and Individual will automatically be saved. Here ContactMedium has the foreign key reference to Individual (and that is what is depicted in your database table screenshot).
Often one use mappedBy as parameter to #OneToMany instead of #JoinColumn to make the relationship two-ways.
Can you please try to change
#OneToMany(cascade =CascadeType.ALL)
#JoinColumn(name = "individual_id")
private List<ContactMedium> contactMedium;
to
#OneToMany(mappedBy = "individual", cascade =CascadeType.ALL)
private List<ContactMedium> contactMedium;
and see if that worked better?
I think you must add the #OneToMany(mappedBy="individual" , cascade =CascadeType.PERSIST) and the #JoinColumn in the #ManyToOne as below:
#OneToMany(mappedBy = "individual", cascade =CascadeType.PERSIST)
private List<ContactMedium> contactMedium;
#ManyToOne
#JoinColumn(name = "individual_id")
private Individual individual;
You should retrieve the entity from the database using the ID first and then update the specific fields and persist the updated entity back.
I have two entities Business which is composed of a list of Departments
#Entity
#Table(name = "Business")
public class Business implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "Id")
private Long id;
#OneToMany(mappedBy = "business",
cascade = {CascadeType.PERSIST, CascadeType.REMOVE})
private List<Department> departments;
#OneToMany(mappedBy = "business", orphanRemoval = true,
cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE})
private List<Process> processs;
#ManyToMany
private List<Competence> competences;
}
#Entity
#Table(name = "Department")
public class Department implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#OneToMany(mappedBy = "father",
cascade = {CascadeType.PERSIST, CascadeType.REMOVE})
private List<Department> departments;
}
When I try to remove a business instance I get a Mysql Exception
Cannot delete or update a parent row: a foreign key constraint fails (evac_java.Department, CONSTRAINT FK_Department_Business FOREIGN KEY (Business) REFERENCES Business (Id)):HY000 - null
Which means I can't delete the business instance because it has departments associated with it, but a department cannot exists by itself so I want to delete all business's departments when it gets removed. I thought I would achieve this by adding cascade = CascadeType.REMOVE to the #OneToMany annotation in the business entity, but it does not work.
I did a search on the net and I found a lot of questions similar to this one on stackoverflow but they all suggest the same: add cascade = CascadeType.REMOVE or CascadeType.ALL
So I'm wondering if I'm missing somethig.
I'm using Glassfish 4.1 and EclipseLink
I tried with
#OneToMany(mappedBy = "business", orphanRemoval = true)
private List<Department> departments;
on the business entity but it does not work either
Here's the method I'm using to remove entities which is declared in an abstract class
public void remove(T entity) {
getEntityManager().remove(getEntityManager().merge(entity));
}
JPA can only remove and cascade the remove over entities it knows about, and if you have not been maintaining both sides of this bidirectional relationship, issues like this will arise. If the collection of departments is empty, try an em.refresh() before the remove, forcing JPA to populate all relationships so that they can be correctly removed, though it is better to maintain both sides of the relationship as changes are made to avoid the database hit.
First of all, sorry for my English.
So, I'm working with MS SQL Server with hibernate and i faced with a problem.
I have next mapping of one of the tables in my DB:
#Entity(name = " ... ")
public class Entity extends BaseEntity implements Comparable {
#Id
#Column(name = "...")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#Column(name = "parent_entity_id", insertable = false, updatable = false)
private Integer parentId;
#ManyToOne(fetch = FetchType.LAZY, cascade = {CascadeType.PERSIST})
#JoinColumn(name = "parent_entity_id")
private Entity parent;
#OneToMany(mappedBy = "parent", fetch = FetchType.LAZY, cascade = {CascadeType.REMOVE}, orphanRemoval = true)
private Set<Entity> children;
//other fields, setters, getters
}
That means, that my Entity objects can have children, which are also an Entity objects.
So, my problems is that I can't correctly delete parent with all his children. When I try to remove parent, i get an SQL error:
The DELETE statement conflicted with the SAME TABLE REFERENCE
So, any ideas, how to solve this problem?
You have a foreign key defined between parent_entity_id and id. Set it to allow cascading deletes: deleting a parent will delete all it's children, and all their children et cetera.
Be sure you actually want this to happen!
I have 2 classes that are connected by a bidirectional ManyToOne / OneToMany relationship:
Member in ClassA:
#OneToMany(cascade = CascadeType.ALL, orphanRemoval = true, mappedBy = "classA")
private List<ClassB> classBList = new ArrayList<ClassB>();
Member in ClassB:
#ManyToOne
#JoinColumn(name = "CLASSA_ID", referencedColumnName = "id")
private ClassA classA;
When I call classA.getClassBList().add(newClassB); a new DB entry for classB is created, but the DB column CLASSA_ID remains null.
of course all entities are defined in persistence.xml.
i appreciate any help, maybe it's just a little detail.
Thanks to bigGuy
My class looks like that now:
#OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
#JoinColumn(name = "CLASSA_ID", referencedColumnName = "id")
private List<ClassB> classBList = new ArrayList<ClassB>();
#ManyToOne
private ClassA classA
The annotation #JoinColumn indicates that this entity is the owner of the relationship.
In your case, owner is ClassB.
So, you should use this line to create relationship:
newClassB.setClassA(classA);
If you want to create relationships with line
classA.getClassBList().add(newClassB);
make ClassA owner of relationship (move #JoinColumn to classA).
I am working with JPA and use Hibernate as a provider to my SQL Server database.
I need a many-to-many self referencing relation that has an additional column or even more additional columns.
That is my current code. I am getting exceptions by Hibernate:
#Entity
public class Person {
#OneToMany(cascade = CascadeType.ALL, mappedBy = "person", fetch = FetchType.EAGER)
private Set<Relation> relations;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "relPerson", fetch = FetchType.EAGER)
private Set<Relation> inverseRelations;
}
#Entity
public class Relation implements Serializable {
#Id
#ManyToOne(cascade = CascadeType.ALL, optional = false, fetch = FetchType.EAGER)
#PrimaryKeyJoinColumn(name = "PersonID", referencedColumnName = "id")
private Person person;
#Id
#ManyToOne(cascade = CascadeType.ALL, optional = false, fetch = FetchType.EAGER)
#PrimaryKeyJoinColumn(name = "RelPersonId", referencedColumnName = "id")
private Person relPerson;
}
During runtime i get an exception from hibernate:
org.hibernate.TransientObjectException: object references an unsaved transient instance
Is there any way to implement this a little bit more intelligent and nicely?? Without getting that exception.
Thanks,
ihrigb
If an object not associated with a Hibernate Session, the object will be Transient.
An instance of Relation list may be Transient(Normally, There is no identifier value for that instance) when you save Person.
Here is better way to understand object state.