I have the following simple application
Users Entity
#Entity
public class Users implements Serializable {
#Id
#GeneratedValue
private long id;
private String name;
#OneToMany(mappedBy = "user", fetch = FetchType.EAGER, cascade = {CascadeType.ALL})
private Set<UserRoleUser> userRoleUser;
// GETTERS AND SETTERS
}
UserRole Entity
#Entity
public class UserRole implements Serializable {
#Id
#GeneratedValue
private long id;
private String roleName;
#OneToMany(mappedBy = "userrole", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
private Set<UserRoleUser> userRoleUser;
// GETTERS AND SETTERS
}
UserRoleUser Many to many resolver class
#Entity
public class UserRoleUser implements Serializable {
#Id
#GeneratedValue
private long id;
#ManyToOne
#JoinColumn(name = "fk_userId")
private Users user;
#ManyToOne
#JoinColumn(name = "fk_userroleId")
private UserRole userrole;
// GETTERS AND SETTERS
}
UserRoleUserRepository
#Repository
#Transactional
public interface UserRoleUserRepository extends JpaRepository<UserRoleUser, Long>, QueryDslPredicateExecutor<UserRoleUser>{
}
Main Application class
#SpringBootApplication
#Configuration
public class Application {
public static void main(String[] args) {
ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
UserRoleUserRepository userRoleUserRepository = context.getBean(UserRoleUserRepository.class);
Iterable<UserRoleUser> findAll = userRoleUserRepository.findAll(QUserRoleUser.userRoleUser.id.gt(0));
for (UserRoleUser userRoleUser : findAll) {
userRoleUserRepository.delete(userRoleUser);
}
}
}
On running the main application, the database records in the UserRoleUser table are not being deleted. What could be the issue? I am using Spring Data and QueryDsl.
I have also tried putting the delete functionality on a Controller but still doesn't work.
#RestController
#RequestMapping("/api")
public class DeleteController {
#Autowired
UserRoleUserRepository userRoleUserRepository;
#GetMapping("/delete")
public String delete() {
Iterable<UserRoleUser> findAll = userRoleUserRepository.findAll(QUserRoleUser.userRoleUser.id.gt(0));
for (UserRoleUser userRoleUser : findAll) {
userRoleUserRepository.delete(userRoleUser);
}
return new Date().toString();
}
}
If you need to use the given methods provided by CrudRepository, use the JpaRepository.deleteInBatch(). This solves the problem.
The problem is the entities are still attached and will not be deleted until they become detached. If you delete by their id instead of the entity itself, it will delete them.
One thing I noticed is you are deleting the users one at a time which could lead to a database performance hit as the query will be recreated each time. The easiest thing to do is to add all the ids to a set then delete the set of ids. Something like this:
Set<Integer> idList = new HashSet<>();
for (UserRoleUser userRoleUser : findAll) {
idList.add(userRoleUser.getId());
}
if (!idList.isEmpty()) {
userRoleUserRepository.delete(idList);
}
then in your repository add the delete method
#Modifying
#Query("DELETE FROM UserRoleUser uru WHERE uru.id in ?1")
#Transactional
void delete(Set<Integer> id);
The reason why the child objects (UserRoleUser) are not being deleted upon userRoleUserRepository.delete(userRoleUser) call is that each UserRoleUser points to a Users which in turn holds a #OneToMany reference Set<UserRoleUser> userRoleUser.
As described in this StackOverflow answer, what your JPA implementation (e.g. Hibernate) effectively does is:
The cache takes note of the requested child exclusion
The cache however does not verify any changes in Set<UserRoleUser>
As the parent #OneToMany field has not been updated, no changes are made
A solution would go through first removing the child element from Set<UserRoleUser> and then proceed to userRoleUserRepository.delete(userRoleUser) or userRepository.save(user)
In order to avoid this complication two answers have been provided:
Remove element by Id, by calling userRoleUserRepository.deleteById(userRoleUser.getId()) : in this case the entity structure (and therefore the parent) is not checked before deletion. In the analog case of deleteAll something more convoluted such as userRoleUserRepository.deleteByIdIn(userRoleUserList.stream().map(UserRoleUser::getId).collect(Collectors.toList())) would have to be employed
Convert your CrudRepository to a JpaRepository and use its deleteInBatch(userRoleUserList) method. As explained in this article and this StackOverflow answer the deleteInBatch method tries to delete all records at once, possibly generating a StackOverflow error in the case the number of records is too large. As repo.deleteAll() removes one record at a time this error it minimizes this risk (unless the call is itself inside a #Transactional method)
According to this StackOverflow answer, extra care should be used when recurring to deleteInBatch as it:
Does not cascade to other entities
Does not update the persistence context, requiring it to be cleared (the method bypasses the cache)
Finally , as far as I know , there is no way this could be done by simply calling userRoleUserRepository.delete(userRoleUser) without first updating the parent object. Any updates on this (whether by allowing such behaviour through annotations, configuration or any other means) would be a welcome addition to the answer.
My question is about cascading deletes with JPA and Eclipselink.
I would like to model a simple relationship between two entities: A and B. B references A through a property ref2a (in DB terms B.ref2a is connected to A.id through a foreign key with "ON DELETE CASCADE").
My goal is when an A object is deleted to cascade the delete to all B objects that reference it.
I searched a lot, but I cannot make it work. Most solutions I have found are for the opposite situation: A contains a collection of references to B. This works like a charm. But if the reference is on the B side, I don't know how to do it.
Here is the Code sample:
#Entity
public class A
{
#Id
#GeneratedValue
private Integer id;
private String name;
// ...
}
#Entity
public class B
{
#Id
#GeneratedValue
private Integer id;
private String name;
#OneToOne
#JoinColumn(
foreignKey=#ForeignKey(
foreignKeyDefinition="FOREIGN KEY ref2a REFERENCES A id ON DELETE CASCADE"
)
)
private A ref2a;
// ...
}
And the test code:
public class CascadeTest extends TestCase
{
private EntityManagerFactory emf;
private EntityManager em;
#Override
protected void setUp() throws Exception {
emf = Persistence.createEntityManagerFactory("myDB");
em = emf.createEntityManager();
}
#Override
protected void tearDown() throws Exception {
em.close();
emf.close();
}
public void testApp()
{
Integer aid = -1, bid = -1;
try {
em.getTransaction().begin();
A a = new A();
a.setName("My name is A");
B b = new B();
b.setRef2a(a);
b.setName("My name is B, please delete me when A is gone.");
em.persist(a);
em.persist(b);
em.getTransaction().commit();
aid = a.getId();
bid = b.getId();
} finally {
if (em.getTransaction().isActive())
em.getTransaction().rollback();
}
try {
em.getTransaction().begin();
B b = em.find(B.class, bid);
assertNotNull(b);
assertEquals("My name is B, please delete me when A is gone.", b.getName());
assertEquals("My name is A", b.getRef2a().getName());
assertEquals(aid, b.getRef2a().getId());
A a = em.find(A.class, aid);
assertEquals("My name is A", a.getName());
em.remove(a);
em.getTransaction().commit();
em.getTransaction().begin();
// a should have been removed.
// This passes OK.
a = em.find(A.class, aid);
assertNull(a);
// Cascading deletes should have deleted also b.
b = em.find(B.class, bid);
// PROBLEM: This fails - b is still here.
assertNull(b);
em.getTransaction().commit();
} finally {
if (em.getTransaction().isActive())
em.getTransaction().rollback();
}
}
}
I have solved my problem. Really really simple - my initial code was almost right. I just had a syntax problem in the foreign key cascade. The attributes needed to be in brackets "()", I had overlooked that in the documentation.
So the change I needed to do is:
#OneToOne
#JoinColumn(
foreignKey=#ForeignKey(
foreignKeyDefinition="FOREIGN KEY (ref2a) REFERENCES A (id) ON DELETE CASCADE"
)
)
private A ref2a;
Please notice the brackets around the two attributes.
This works, deleting an A object also cascades its linked B objects.
Thanks to everybody for your help!
EclipseLink provides a #CascadeOnDelete annotation that aligns with database "ON DELETE CASCADE" contraint. This annotation tells EclipseLink that the entity will be deleted by the database foriegn key constraint when this entity is deleted, and if using DDL, EclipseLink will generate the table with the proper constraint.
see https://wiki.eclipse.org/EclipseLink/Examples/JPA/DeleteCascade for details.
I think though that you can get by with a simple cascade delete on the FriendshipRelation.person mapping:
#Entity
public class FriendshipRelation {
..
#OneToOne(cascade=CascadeType.REMOVE)
private Person person;
This will force JPA to remove any referenced person when the FriendshipRelation instance is removed.
I am trying to do a simple example using java.util.Map in Hibernate by creating a Customer entity with a Map of Order entities.
Here are my Java classes:
Customer.java:
#Entity
public class Customer {
#Id
#GeneratedValue
private Integer id;
#OneToMany(mappedBy = "customer")
#MapKey(name = "orderNumber")
private Map<String, Order> orders = new HashMap<String, Order>();;
}
Order.java
#Entity
#Table(name="TB_ORDER")
public class Order {
#Id
#GeneratedValue
private Integer id;
private String orderNumber;
#ManyToOne
private Customer customer;
}
Now I have created a program to save a customer and Orders:
public class AppTest {
public static void main(String[] args) {
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
saveCustomer(session);
HibernateUtil.getSessionFactory().close();
}
private static void saveCustomer(Session session) {
session.getTransaction().begin();
Customer customer = new Customer();
Order order = new Order();
order.setCustomer(customer);
//order.setOrderNumber("100");
Map<String, Order> map = new HashMap();
map.put("100", order);
customer.setOrders(map);
session.save(customer);
session.save(order);
session.getTransaction().commit();
}
}
As per my mapping, the key of Map represents the orderNumber property of my Order class. So when I created a map with key as "100" and trying save using Hibernate then the field is set as empty in my database for TB_ORDER table. But if I try to use order.setOrderNumber("100") then the value is getting saved to database. Please tell me where I am doing mistake?
You're not doing any mistake. It's your responsibility to maintain the coherence of the object graph in memory. What is mapped to the column in the database is the orderNumber field of the Order entity. So if it's null, Hibernate saves null in the column.
The MapKey annotation tells Hibernate how to extract the key from the entity when it loads a Customer's orders from the database and populates the map. That's all.
I have a spring 4 app where I'm trying to delete an instance of an entity from my database. I have the following entity:
#Entity
public class Token implements Serializable {
#Id
#SequenceGenerator(name = "seqToken", sequenceName = "SEQ_TOKEN", initialValue = 500, allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seqToken")
#Column(name = "TOKEN_ID", nullable = false, precision = 19, scale = 0)
private Long id;
#NotNull
#Column(name = "VALUE", unique = true)
private String value;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "USER_ACCOUNT_ID", nullable = false)
private UserAccount userAccount;
#Temporal(TemporalType.TIMESTAMP)
#Column(name = "EXPIRES", length = 11)
private Date expires;
...
// getters and setters omitted to keep it simple
}
I have a JpaRepository interface defined:
public interface TokenRepository extends JpaRepository<Token, Long> {
Token findByValue(#Param("value") String value);
}
I have a unit test setup that works with an in memory database (H2) and I am pre-filling the database with two tokens:
#Test
public void testDeleteToken() {
assertThat(tokenRepository.findAll().size(), is(2));
Token deleted = tokenRepository.findOne(1L);
tokenRepository.delete(deleted);
tokenRepository.flush();
assertThat(tokenRepository.findAll().size(), is(1));
}
The first assertion passes, the second fails. I tried another test that changes the token value and saves that to the database and it does indeed work, so I'm not sure why delete isn't working. It doesn't throw any exceptions either, just doesn't persist it to the database. It doesn't work against my oracle database either.
Edit
Still having this issue. I was able to get the delete to persist to the database by adding this to my TokenRepository interface:
#Modifying
#Query("delete from Token t where t.id = ?1")
void delete(Long entityId);
However this is not an ideal solution. Any ideas as to what I need to do to get it working without this extra method?
Most probably such behaviour occurs when you have bidirectional relationship and you're not synchronizing both sides WHILE having both parent and child persisted (attached to the current session).
This is tricky and I'm gonna explain this with the following example.
#Entity
public class Parent {
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Long id;
#OneToMany(cascade = CascadeType.PERSIST, mappedBy = "parent")
private Set<Child> children = new HashSet<>(0);
public void setChildren(Set<Child> children) {
this.children = children;
this.children.forEach(child -> child.setParent(this));
}
}
#Entity
public class Child {
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Long id;
#ManyToOne
#JoinColumn(name = "parent_id")
private Parent parent;
public void setParent(Parent parent) {
this.parent = parent;
}
}
Let's write a test (a transactional one btw)
public class ParentTest extends IntegrationTestSpec {
#Autowired
private ParentRepository parentRepository;
#Autowired
private ChildRepository childRepository;
#Autowired
private ParentFixture parentFixture;
#Test
public void test() {
Parent parent = new Parent();
Child child = new Child();
parent.setChildren(Set.of(child));
parentRepository.save(parent);
Child fetchedChild = childRepository.findAll().get(0);
childRepository.delete(fetchedChild);
assertEquals(1, parentRepository.count());
assertEquals(0, childRepository.count()); // FAILS!!! childRepostitory.counts() returns 1
}
}
Pretty simple test right? We're creating parent and child, save it to database, then fetching a child from database, removing it and at last making sure everything works just as expected. And it's not.
The delete here didn't work because we didn't synchronized the other part of relationship which is PERSISTED IN CURRENT SESSION. If Parent wasn't associated with current session our test would pass, i.e.
#Component
public class ParentFixture {
...
#Transactional(propagation = Propagation.REQUIRES_NEW)
public void thereIsParentWithChildren() {
Parent parent = new Parent();
Child child = new Child();
parent.setChildren(Set.of(child));
parentRepository.save(parent);
}
}
and
#Test
public void test() {
parentFixture.thereIsParentWithChildren(); // we're saving Child and Parent in seperate transaction
Child fetchedChild = childRepository.findAll().get(0);
childRepository.delete(fetchedChild);
assertEquals(1, parentRepository.count());
assertEquals(0, childRepository.count()); // WORKS!
}
Of course it only proves my point and explains the behaviour OP faced. The proper way to go is obviously keeping in sync both parts of relationship which means:
class Parent {
...
public void dismissChild(Child child) {
this.children.remove(child);
}
public void dismissChildren() {
this.children.forEach(child -> child.dismissParent()); // SYNCHRONIZING THE OTHER SIDE OF RELATIONSHIP
this.children.clear();
}
}
class Child {
...
public void dismissParent() {
this.parent.dismissChild(this); //SYNCHRONIZING THE OTHER SIDE OF RELATIONSHIP
this.parent = null;
}
}
Obviously #PreRemove could be used here.
I had the same problem
Perhaps your UserAccount entity has an #OneToMany with Cascade on some attribute.
I've just remove the cascade, than it could persist when deleting...
You need to add PreRemove function ,in the class where you have many object as attribute e.g in Education Class which have relation with UserProfile
Education.java
private Set<UserProfile> userProfiles = new HashSet<UserProfile>(0);
#ManyToMany(fetch = FetchType.EAGER, mappedBy = "educations")
public Set<UserProfile> getUserProfiles() {
return this.userProfiles;
}
#PreRemove
private void removeEducationFromUsersProfile() {
for (UsersProfile u : usersProfiles) {
u.getEducationses().remove(this);
}
}
One way is to use cascade = CascadeType.ALL like this in your userAccount service:
#OneToMany(cascade = CascadeType.ALL)
private List<Token> tokens;
Then do something like the following (or similar logic)
#Transactional
public void deleteUserToken(Token token){
userAccount.getTokens().remove(token);
}
Notice the #Transactional annotation. This will allow Spring (Hibernate) to know if you want to either persist, merge, or whatever it is you are doing in the method. AFAIK the example above should work as if you had no CascadeType set, and call JPARepository.delete(token).
This is for anyone coming from Google on why their delete method is not working in Spring Boot/Hibernate, whether it's used from the JpaRepository/CrudRepository's delete or from a custom repository calling session.delete(entity) or entityManager.remove(entity).
I was upgrading from Spring Boot 1.5 to version 2.2.6 (and Hibernate 5.4.13) and had been using a custom configuration for transactionManager, something like this:
#Bean
public HibernateTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
return new HibernateTransactionManager(entityManagerFactory.unwrap(SessionFactory.class));
}
And I managed to solve it by using #EnableTransactionManagement and deleting the custom
transactionManager bean definition above.
If you still have to use a custom transaction manager of sorts, changing the bean definition to the code below may also work:
#Bean
public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
return new JpaTransactionManager(entityManagerFactory);
}
As a final note, remember to enable Spring Boot's auto-configuration so the entityManagerFactory bean can be created automatically, and also remove any sessionFactory bean if you're upgrading to entityManager (otherwise Spring Boot won't do the auto-configuration properly). And lastly, ensure that your methods are #Transactional if you're not dealing with transactions manually.
I was facing the similar issue.
Solution 1:
The reason why the records are not being deleted could be that the entities are still attached. So we've to detach them first and then try to delete them.
Here is my code example:
User Entity:
#Entity
public class User {
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "user")
private List<Contact> contacts = new ArrayList<>();
}
Contact Entity:
#Entity
public class Contact {
#Id
private int cId;
#ManyToOne
private User user;
}
Delete Code:
user.getContacts().removeIf(c -> c.getcId() == contact.getcId());
this.userRepository.save(user);
this.contactRepository.delete(contact);
Here we are first removing the Contact object (which we want to delete) from the User's contacts ArrayList, and then we are using the delete() method.
Solution 2:
Here we are using the orphanRemoval attribute, which is used to delete orphaned entities from the database. An entity that is no longer attached to its parent is known as an orphaned entity.
Code example:
User Entity:
#Entity
public class User {
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "user", orphanRemoval = true)
private List<Contact> contacts = new ArrayList<>();
}
Contact Entity:
#Entity
public class Contact {
#Id
private int cId;
#ManyToOne
private User user;
}
Delete Code:
user.getContacts().removeIf(c -> c.getcId() == contact.getcId());
this.userRepository.save(user);
Here, as the Contact entity is no longer attached to its parent, it is an orphaned entity and will be deleted from the database.
I just went through this too. In my case, I had to make the child table have a nullable foreign key field and then remove the parent from the relationship by setting null, then calling save and delete and flush.
I didn't see a delete in the log or any exception prior to doing this.
If you use an newer version of Spring Data, you could use deleteBy syntax...so you are able to remove one of your annotations :P
the next thing is, that the behaviour is already tract by a Jira ticket:
https://jira.spring.io/browse/DATAJPA-727
#Transactional
int deleteAuthorByName(String name);
you should write #Transactional in Repository extends JpaRepository
Your initial value for id is 500. That means your id starts with 500
#SequenceGenerator(name = "seqToken", sequenceName = "SEQ_TOKEN",
initialValue = 500, allocationSize = 1)
And you select one item with id 1 here
Token deleted = tokenRepository.findOne(1L);
So check your database to clarify that
I've the same problem, test is ok but on db row isn't deleted.
have you added the #Transactional annotation to method? for me this change makes it work
In my case was the CASCADE.PERSIST, i changed for CASCADE.ALL, and made the change through the cascade (changing the father object).
CascadeType.PERSIST and orphanRemoval=true doesn't work together.
Try calling deleteById instead of delete on the repository. I also noticed that you are providing an Optional entity to the delete (since findOne returns an Optional entity). It is actually strange that you are not getting any compilation errors because of this. Anyways, my thinking is that the repository is not finding the entity to delete.
Try this instead:
#Test
public void testDeleteToken() {
assertThat(tokenRepository.findAll().size(), is(2));
Optional<Token> toDelete = tokenRepository.findOne(1L);
toDelete.ifExists(toDeleteThatExists -> tokenRepository.deleteById(toDeleteThatExists.getId()))
tokenRepository.flush();
assertThat(tokenRepository.findAll().size(), is(1));
}
By doing the above, you can avoid having to add the #Modifying query to your repository (since what you are implementing in that #Modifying query is essentially the same as calling deleteById, which already exists on the JpaRepository interface).
Imagine the following models:
Employee:
#ManyToMany(cascade = CascadeType.ALL)
#JoinTable(name = "employee_project", joinColumns = #JoinColumn(name = "Emp_Id"), inverseJoinColumns = #JoinColumn(name = "Proj_id"))
private Set<Project> projects = new HashSet<Project>();
Project:
#ManyToMany(mappedBy = "projects")
private Set<Employee> employees = new HashSet<Employee>();
Now if I create a new employee that refers to an existing project and try to persist that employee, I get an error:
detached entity passed to persist: Project
I create the employee as follows:
public void createNewEmployee(EmployeeDTO empDTO) {
Employee emp = new Employee();
// add stuff from DTO, including projects
repository.saveAndFlush(emp); // FAILS
}
and I update existing ones like this:
public void updateEmployee(EmployeeDTO empDTO) {
Employee emp = repository.findOne(empDTO.getId());
// set stuff from DTO, including projects
repository.saveAndFlush(emp); // WORKS!
}
I guess you're interacting with the repository without expanding the transaction boundaries appropriately. By default, the transaction (and thus session) boundary is at the repository method level. This causes the Project instance to be detached from the EntityManager, so that it cannot be included in a persist operation.
The solution here is to extend the transaction boundary to the client:
#Component
class YourRepositoryClient {
private final ProjectRepository projects;
private final EmployeeRepository employees;
// … constructor for autowiring
#Transactional
public void doSomething() {
Project project = projects.findOne(1L);
Employee employee = employees.save(new Employee(project));
}
}
This approach causes the Project instance stay a managed entity and thus the persist operation to be executed for the fresh Employee instance being handled correctly.
The difference with the two repository interactions is that in the second case you'll have a detached instance (has already been persisted, has an id set), where as in the first example you have a completely unmanaged instances that does not have an id set. The id property is what causes the repository to differentiate between calling persist(…) and merge(…). So the first approach will cause a persist(…) to be triggered, the second will cause a merge(…).