Develop Reference

How created multi update query with JPA data?

I try to create query setAll , because a entity with top isValid and I want all value to false before I use saveAll for udpade my database. I use this methods synchronize my database with a batch 6000-7000 lines actually.
import org.springframework.data.repository.CrudRepository;
public interface DomRepository extends CrudRepository<Dom, String> {
public Domaine findDomByName(String dom);
public List<Dom> findAll();
public void setIsValidAll(boolean isValid);
}
import javax.persistence.*;
import org.hibernate.annotations.DynamicUpdate;
import org.springframework.data.annotation.CreatedDate;
#Entity
#DynamicUpdate
public class Dom{
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private int id;
private String name;
// more attribute
private boolean isValid;
Caused by: org.springframework.data.mapping.PropertyReferenceException: No property 'setIsValidAll' found for type 'Dom'!

It's not entirely clear what you want to achieve based on the description you have provided but if I get this right, you would like to create a repository when that will effectively update the value of the isValid field for all Dom objects. If that is indeed the case then you could simply create a custom repository method that will accept your flag and will make use of a simple HQL or JPQL to update all records in the database. For example something like this could work for this case:
#Modifying
#Query("UPDATE Dom SET isValid = :valid")
void updateValidAll(boolean valid);
If on the other hand you want to perform the update in memory on the fetched entities and then perform a saveAll you could do something like this:
#Transactional
public void updateAllRecords2(boolean isValid) {
var records = repository.findAll()
.stream()
.peek(dom -> dom.setValid(isValid))
.toList();
repository.saveAll(records);
}
Note that the latter is not very optimal as it uses peek which should not be used on operations that have side-effects (i.e mutations). On top of that will will perform an update query for every single entity that is present, meaning N queries for N entities.

JPA method increases version field of searching entity

I'm using Spring boot 2.7.0
And have the next entities in simple:
#Getter
#Setter
#Entity
public class Account {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Version
private Long version;
private String name;
}
#Getter
#Setter
#Entity
public class Event {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne
Account account;
private String message;
}
and jpa repositories:
#Repository
public interface AccountRepository extends JpaRepository<Account, Long> {
}
#Repository
public interface EventRepository extends JpaRepository<Event, Long> {
Page<Event> findAllByAccount(Account account, Pageable pageable);
}
In short I call
eventRepository.findAllByAccount(accountRepository.findById(1), PageRequest.of(1,10));
Problem is every call of last code increases the version field of Account by 1. So question is why? I don't call any update or save method.
And additionally the result of this behaviour is calling of method needs
#Transactional(readonly=false)
Otherwise if I write readonly=true that throws cannot execute UPDATE in a read-only transaction
ADDED:
full code of usage:
#Transactional
public Page<Event> events(Long accountId, int page) {
return eventRepository.findByAccount(findById(accountId), PageRequest.of(page, PAGE_SIZE));
}
#GetMapping("/events")
public List<EventResponse> listEvents(#RequestParam(value = "max", defaultValue = "0") int page) {
return eventService.events(1L, page).stream().map(EventResponse::of).toList();
}

It looks like hibernate is deriving lockMode type as either of WRITE or OPTIMISTIC_FORCE_INCREMENT or PESSIMISTIC_FORCE_INCREMENT based on isolation level of your database. As per reference hibernate decides this pessimistic locking by its own based on database you use.
As per doc, if lockmode type is either of what I mentioned above, Version will get automatically incremented even if you haven't changed anything i.e. even if you haven't do any update or save.
Please check database isolation level & based on that you might get an idea about this.
Edit: as you explicitly setting lockmode as write so my answer validates that because of WRITE mode, your version got incremented automatically.

The problem should be related in the code which is using the result of the find.
If you're modifying entities under a transaction they're going to be modified at the end of the method, when Spring in this case is going to close the transaction. In this part when transaction ends, the JPA provider (for example hibernate) aligns the relative entity record into the database with the 'java entity object' by an update.

I'm sorry. After trim all my code to the posted and debug I found my mistake:
In the begin I was retrieving Account in another method by .lock(Long) method instead of .findById(Long)
lock method is below:
#Lock(LockModeType.WRITE)
#Query("from Account where id = :id")
public Optional<Account> lock(Long id);

JPA "select new" feature with manytomany relationship: array in constructor signature

I have some entities like this (a post with some tags associated with):
#Entity
public class Post {
#GeneratedId
public Long id;
#ManyToMany(cascade=CascadeType.PERSIST, fetch = FetchType.LAZY)
public Set<Tag> tags = new HashSet<Tag>();
...
}
#Entity
public class Tag {
#GeneratedId
public Long id;
public String name;
}
I have to make some requests that returns hundreds of Posts with filtering on tags.
Up to now, I have used standard queries returning some Post entities, then accessing the myPost.tags to create my POJO.
This is really time consuming because each time I create a POJO, I call myPost.tags which makes a request to get them. I thought it was a good idea to use the select new feature like this:
select distinct new PostDTO(p.id, t) from Post p left outer join p.tags as t where ...
with
public class PostDTO {
public PostDTO(Long id, Tag[] tags) {...}
}
Unfortunately, due to JPQL: Receiving a Collection in a Constructor Expression the tags could not be passed as an array.
So my question: how can I do? Do I have to change my schema? or JPA has a feature that I've missed?

How to beautifully update a JPA entity in Spring Data?

So I have looked at various tutorials about JPA with Spring Data and this has been done different on many occasions and I am no quite sure what the correct approach is.
Assume there is the follwing entity:
package stackoverflowTest.dao;
import javax.persistence.*;
#Entity
#Table(name = "customers")
public class Customer {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private long id;
#Column(name = "name")
private String name;
public Customer(String name) {
this.name = name;
}
public Customer() {
}
public long getId() {
return id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
We also have a DTO which is retrieved in the service layer and then handed to the controller/client side.
package stackoverflowTest.dto;
public class CustomerDto {
private long id;
private String name;
public CustomerDto(long id, String name) {
this.id = id;
this.name = name;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
So now assume the Customer wants to change his name in the webui - then there will be some controller action, where there will be the updated DTO with the old ID and the new name.
Now I have to save this updated DTO to the database.
Unluckily currently there is no way to update an existing customer (except than deleting the entry in the DB and creating a new Cusomter with a new auto-generated id)
However as this is not feasible (especially considering such an entity could have hundreds of relations potentially) - so there come 2 straight forward solutions to my mind:
make a setter for the id in the Customer class - and thus allow setting of the id and then save the Customer object via the corresponding repository.
or
add the id field to the constructor and whenever you want to update a customer you always create a new object with the old id, but the new values for the other fields (in this case only the name)
So my question is wether there is a general rule how to do this?
Any maybe what the drawbacks of the 2 methods I explained are?

Even better then #Tanjim Rahman answer you can using Spring Data JPA use the method T getOne(ID id)
Customer customerToUpdate = customerRepository.getOne(id);
customerToUpdate.setName(customerDto.getName);
customerRepository.save(customerToUpdate);
Is's better because getOne(ID id) gets you only a reference (proxy) object and does not fetch it from the DB. On this reference you can set what you want and on save() it will do just an SQL UPDATE statement like you expect it. In comparsion when you call find() like in #Tanjim Rahmans answer spring data JPA will do an SQL SELECT to physically fetch the entity from the DB, which you dont need, when you are just updating.

In Spring Data you simply define an update query if you have the ID
#Repository
public interface CustomerRepository extends JpaRepository<Customer , Long> {
#Query("update Customer c set c.name = :name WHERE c.id = :customerId")
void setCustomerName(#Param("customerId") Long id, #Param("name") String name);
}
Some solutions claim to use Spring data and do JPA oldschool (even in a manner with lost updates) instead.

Simple JPA update..
Customer customer = em.find(id, Customer.class); //Consider em as JPA EntityManager
customer.setName(customerDto.getName);
em.merge(customer);

This is more an object initialzation question more than a jpa question, both methods work and you can have both of them at the same time , usually if the data member value is ready before the instantiation you use the constructor parameters, if this value could be updated after the instantiation you should have a setter.

If you need to work with DTOs rather than entities directly then you should retrieve the existing Customer instance and map the updated fields from the DTO to that.
Customer entity = //load from DB
//map fields from DTO to entity

So now assume the Customer wants to change his name in the webui -
then there will be some controller action, where there will be the
updated DTO with the old ID and the new name.
Normally, you have the following workflow:
User requests his data from server and obtains them in UI;
User corrects his data and sends it back to server with already present ID;
On server you obtain DTO with updated data by user, find it in DB by ID (otherwise throw exception) and transform DTO -> Entity with all given data, foreign keys, etc...
Then you just merge it, or if using Spring Data invoke save(), which in turn will merge it (see this thread);
P.S. This operation will inevitably issue 2 queries: select and update. Again, 2 queries, even if you wanna update a single field. However, if you utilize Hibernate's proprietary #DynamicUpdate annotation on top of entity class, it will help you not to include into update statement all the fields, but only those that actually changed.
P.S. If you do not wanna pay for first select statement and prefer to use Spring Data's #Modifying query, be prepared to lose L2C cache region related to modifiable entity; even worse situation with native update queries (see this thread) and also of course be prepared to write those queries manually, test them and support them in the future.

I have encountered this issue!
Luckily, I determine 2 ways and understand some things but the rest is not clear.
Hope someone discuss or support if you know.
Use RepositoryExtendJPA.save(entity). Example:
List<Person> person = this.PersonRepository.findById(0)
person.setName("Neo");
This.PersonReository.save(person);
this block code updated new name for record which has id = 0;
Use #Transactional from javax or spring framework. Let put #Transactional upon your class or specified function, both are ok. I read at somewhere that this annotation do a "commit" action at the end your function flow. So, every things you modified at entity would be updated to database.

There is a method in JpaRepository
getOne
It is deprecated at the moment in favor of
getById
So correct approach would be
Customer customerToUpdate = customerRepository.getById(id);
customerToUpdate.setName(customerDto.getName);
customerRepository.save(customerToUpdate);

org.hibernate.exception.SQLGrammarException: could not execute query

I use play framework !! But when I run my project it give me this
org.hibernate.exception.SQLGrammarException: could not execute query
who can help me ?
this is my model:
package models;
import java.util.*;
import javax.persistence.*;
import play.db.jpa.*;
import play.db.jpa.Model;
#Entity
#Table(name="GxkAccount")
public class GxkAccount extends Model {
private String Account;
private String Psw;
public String getAccount() {
return Account;
}
public void setAccount(String account) {
Account = account;
}
public String getPsw() {
return Psw;
}
public void setPsw(String psw) {
Psw = psw;
}
public static List<GxkAccount> GetList()
{
List<GxkAccount> infoList=GxkAccount.findAll();
return infoList;
}
}

You are completely missing the mapping annotations for the properties of your class.
P.S. Please try to follow the Java naming conventions

Using mysql, we also faced this type of issue. We found in play framework application.conf:
jpa.dialect=org.hibernate.dialect.PostgreSQLDialect
we replaced this with
jpa.dialect=org.hibernate.dialect.MySqlDialect.
This solved the problem. If you are facing this issue you can try out this configuration setting.

We also faced the same issue. We were having create in the xml and #GeneratedValue on the id column. The resolution is remove the #GeneratedValue annotation and put the value of the id manually, also the jpa takes long by default so give long value e.g 1l.
To do the auto generation follow some another rule.
The issue around the JPA related auto generated Id is resolved as below:
Modify the Person.java model class to have the following annotations for the Id attribute:
#Id
#TableGenerator(name="TABLE_GEN",table="T_GENERATOR",pkColumnName="GEN_KEY",pkColumnValue="TEST",valueColumnName="GEN_VALUE",initialValue=1,allocationSize=1)
#GeneratedValue(strategy=GenerationType.TABLE, generator="TABLE_GEN")
public Long Id;
This will create a table in the mysql schema called T_GNERATOR which will have the tracking of the next value for Id and JPA over hibernate knows how to retrieve this value. The assumption is that the initial value for the Id is 1 and it is incremented by 1 on each new insertion into it as is obvious from the attributes of the annotation.