Hibernate Fetch #Formula annotated fields on demand - spring

I have a entity (declared with 2 way)(some not influencing code part are ommited for readability)
Entity version 1.
#Entity
public class Article {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name = "name")
private String name;
#Formula("(SELECT COUNT(w.id) FROM stock s LEFT JOIN warehouse w ON s.id=w.stock_id WHERE s.article_id = id)")
private int variants;
public int getVariants() {
return variants;
}
}
Entity version 2.
#Entity
public class Article {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name = "name")
private String name;
#Transient
private int variants;
#Access(AccessType.PROPERTY)
#Formula("(SELECT COUNT(w.id) FROM stock s LEFT JOIN warehouse w ON s.id=w.stock_id WHERE s.article_id = id)")
public int getVariants() {
return variants;
}
}
respective DTO and ArticleMapper - MapStruct
#JsonIgnoreProperties(ignoreUnknown = true)
public class ArticleDTOCommon {
private Long id;
private String name;
}
#JsonIgnoreProperties(ignoreUnknown = true)
public class ArticleDTO {
private Long id;
private String name;
private int variants;
}
#Mapper(componentModel = "spring", uses = {})
public interface ArticleMapper{
ArticleDTO toDto(Article article);
ArticleDTOCommon toDtoCommon(Article article);
}
I have a #Service layer on which how i know Hibernate creates it's proxy(for defining which field is fetch or not fetch) and transactions are occurs.
#Service
#Transactional
public class ArticleService {
#Transactional(readOnly = true)
public List<ArticleDTO> findAll() {
return articleRepository.findAll()
stream().map(articleMapper::toDto).collect(Collectors.toList());
}
#Transactional(readOnly = true)
public List<ArticleDTO> findAllCommon() {
return articleRepository.findAll()
stream().map(articleMapper::toDtoCommon).collect(Collectors.toList());
}
}
It works fine with fetching Related entity but
Problem is (fetching #Formula annotated field) when I am looking executed query on log it fetchs all time variants #Formula annotated query not depending on respective DTO.
But it must be ignored on toDtoCommon - i.e. It must not fetch variants field -> because when mapping Article to ArticleDtoCommon it not uses getVariant() field of Article. I have tried multiple ways as mentioned above.
I can solve it with writing native query(for findAllCommon() method) and map respectivelly with other way... But I want to know that how we can solve it with ORM way and where is problem.
Manupulating #Access type is not helping too.
Thanks is advance.

Related

Automatic JPA refresh ManyToOne objects with #Version feature

I'm getting an exception:
org.hibernate.TransientPropertyValueException:
object references an unsaved transient instance
- save the transient instance before flushing :
com.example.jpamapstruct.entity.Member.club ->
com.example.jpamapstruct.entity.Club
while saving the member entity:
#Transactional
public MemberDto save(MemberDto memberDto){
Member entity = memberMapper.toEntity(memberDto);
return memberMapper.toDto(repository.save(entity));
}
How to fix this case in a proper way?
Possible solution:
I can get and set a club object before saving a member but is it only one and the best approach in such scenario?
Member entity = memberMapper.toEntity(memberDto);
clubRepository.getReferencedById(memberDto.getClubId()).ifPresent(entity::setClub);
return memberMapper.toDto(repository.save(entity));
Questions:
Should I put this getReferencedById code explicity? I mean what if we have several child objects (unidirectional ManyToOne), for each we need to get data from DB.
Is there any way to handle this by JPA (Spring Data/JPA) "automatically"?
Maybe it is possible to hit DB only one time with f.e join fetch somehow for all childs (with using custom #Query or querydsl or criteria/specification)?
Next, hoow to handle collections (unidirectional manyToMany)? In my case set of events in member object. Also need to loop thru and get all objects one by one before saving member?
Where should I put such logic in a service or maybe better in a mapstuct mapper?
If so, how to use repositories in such mapper?
#Mapper(componentModel = "spring")
public interface MemberMapper extends EntityMapper<MemberDto, Member> {
#AfterMapping
default void afterMemberMapping(#MappingTarget Member m, MemberDto dto) {
var club = clubRepo.findById(m.getClub().getId())
m.setClub(club)
}
Source code:
#Entity
public class Club extends AbstractEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", nullable = false)
private Long id;
}
public class ClubDto extends AbstractDto {
private Long id;
}
#Entity
public class Member {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Long id;
// commented out as don't want to save child object as it should already exist
// #ManyToOne(cascade = CascadeType.ALL)
#ManyToOne
Club club;
#ManyToMany
#JoinTable(name = "member_events",
joinColumns = #JoinColumn(name = "member_id"),
inverseJoinColumns = #JoinColumn(name = "event_id")
)
List<Event> events = new ArrayList<>();
}
public class MemberDto {
private Long id;
private ClubDto club;
}
#MappedSuperclass
public abstract class AbstractEntity {
#Version
private Integer version;
}
public abstract class AbstractDto {
private Integer version;
}
//MemberMapper above

How can I add a tenant condition to Spring Data JPA Default and Dervied Queries

I have a Springboot Application with Repositories having Spring Data JPA Queries like findOne, findAll and also derived ones like findByID or findByName etc.
What I want to achieve is multitenancy. All entities have an "account_id" column which holds the tenant.
How do I add a filter like "account_id" to all the queries metioned above without using derived queries that contains those name slike findIdAndAccountid (which would be findone)
#Repository
public interface CategoryRepository extends JpaRepository<Category, Long> {
Category findByName(String name);
}
Here's the corresponding entity
#Entity
#Table(name = "unit")
#Data
public class Unit {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long id;
private String name;
#Column(name = "account_id")
private Long account_id;
}
I know most people use schemas as tenant separation but that's impossible for me. Is there a way (I didn't find one) to add such a tenant filter condition on those queries without writing NamedQueries or using DerivedQueries. An elegeant solution like annotate the repository or entity or maybe the queries that all queries should add the additional filter "account_id"?
You can add Where clause on your Entity classes (Didnt had time to test )
#Entity
#Table(name = "unit")
#Data
#Where(clause = "account_id= :account_id")
public class Unit {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long id;
private String name;
#Column(name = "account_id")
private Long account_id;
}
Update and Solution
1. Create a Filter & FilterDef on the entity like so
#FilterDef(name="accountFilter", parameters=#ParamDef( name="accountId", type="long" ) )
#Filters( {
#Filter(name="accountFilter", condition=":accountId = account_id")
} )
public class Category {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long id;
private String name;
#Column(name = "account_id")
private Long account_id;
}
enable filtering in the controller by autowiring entitymanager, writing a method to enable the filter and activate the filter in #ModelAttribute for each request
#RestController
#RequestMapping(path = "/categories",produces = MediaType.APPLICATION_JSON_VALUE )
public class CategoryController {
private final CategoryRepository repository;
#Autowired
private EntityManager entityManager;
CategoryController(CategoryRepository repository) {
this.repository = repository;
}
private void activateFilter() {
Session session = entityManager.unwrap(Session.class);
Filter filter = session.enableFilter("accountFilter");
filter.setParameter("accountId", Long.valueOf(TenantContext.getCurrentTenant()));
}
#ModelAttribute
public void initFilter() {
activateFilter();
}
... your rest methods here
}

Saving entity with composite key get ConversionNotSupportedException

I use spring boot 2 and some of my entities have composite key
When I try to save an entity, I get this error
Failed to convert request element:
org.springframework.beans.ConversionNotSupportedException: Failed to
convert property value of type 'java.lang.Integer' to required type
'com.lcm.model.SamplingsPK' for property 'sampling'; nested exception
is java.lang.IllegalStateException: Cannot convert value of type
'java.lang.Integer' to required type 'com.lcm.model.SamplingsPK' for
property 'sampling': no matching editors or conversion strategy found
I get my entity with that method
public Samples findById(Integer id, int year, String sampleLetter) {
Optional<Samples> optSamples = samplesRepository.findById(new SamplesPK(new SamplingsPK(year, id), sampleLetter));
if (optSamples.isPresent()) {
return optSamples.get();
}
return null;
}
Samples samples = samplesService.findById(idSeq, year, samplesLetter);
Compressions compressionTest = null;
if (samples.getTestSamples().getAbsorptionTest() != null) {
compressionTest = samples.getTestSamples().getCompressionTest();
} else {
compressionTest = new Compressions();
}
samplesService.save(samples);
My entity
#Entity
#IdClass(SamplesPK.class)
public class Samples extends BaseEntity{
#Id
private String sampleLetter;
#Embedded
private TestSamples testSamples;
#Id
#ManyToOne(optional=false)
#JoinColumns({
#JoinColumn(name = "sampling_id", referencedColumnName = "id"),
#JoinColumn(name = "sampling_year", referencedColumnName = "year")})
private Samplings sampling;
}
#Entity
#IdClass(SamplingsPK.class)
#Inheritance(strategy = InheritanceType.SINGLE_TABLE)
public class Samplings {
#Id
private Integer year;
#Id
#GeneratedValue
private Integer id;
#OneToMany(mappedBy = "sampling", cascade = CascadeType.ALL, orphanRemoval = true)
private List<Samples> samples = new ArrayList<>();
}
public class SamplingsPK implements Serializable {
private int year;
private Integer id;
public SamplingsPK(int year, Integer id) {
this.id = id;
this.year = year;
}
}
public class SamplesPK implements Serializable {
private SamplingsPK sampling;
private String sampleLetter;
public SamplesPK(SamplingsPK sampling, String sampleLetter) {
this.sampling = sampling;
this.sampleLetter = sampleLetter;
}
}
edit
no problem to save sample, when I pass from sampling
The problem is that since the IDs are set manually and there's no #Version property on these entities then Spring Data has no good way of knowing if the entity is a brand new one or an existing one. In this case it decides it is an existing entity and attempts a merge instead of a persist. This is obviously a wrong conclusion.
You can read more about how Spring Data decides if an entity is new or not here.
The best solution I've found is to always let entity classes with manually set IDs implement Persistable interface. This solves the problem. I make this a rule for myself for any such case. Most of the time I do not have to implement Persistable because my entity either has an auto-generated key or my entity uses a "#Version" annotation. But this is special case.
So, as per the recommendation in the Spring official documentation, for example the Samplings class would become:
#Entity
#IdClass(SamplingsPK.class)
#Inheritance(strategy = InheritanceType.SINGLE_TABLE)
public class Samplings implements Persistable<SamplingsPK> {
#Transient
private boolean isNew = true;
#Id
private Integer year;
#Id
#GeneratedValue
private Integer id;
#OneToMany(mappedBy = "sampling", cascade = CascadeType.ALL, orphanRemoval = true)
private List<Samples> samples = new ArrayList<>();
#Override
public boolean isNew() {
return isNew;
}
#PrePersist
#PostLoad
void markNotNew() {
this.isNew = false;
}
#Override
public SamplingsPK getId() {
return new SamplingsPK(year, id);
}
}
This issue is tracked at https://jira.spring.io/browse/DATAJPA-1391 and has to do with the use of #Id #ManyToOne inside of Samples. As a workaround, you can try creating a constructor for Samplings that takes in its two primary keys, or maybe one that takes a java.lang.Integer? That's what worked for a single level of composite primary keys, but it might not work if you have multiple levels.
You also have year in SamplingsPK typed as an int rather than an Integer. This may cause problems with PK recognition, since special consideration is needed to handle autobox-able primitive classes and I doubt it was considered.
I noticed this too. It does not happen on my IDE on Windows but it happens on the Azure build server
I was on org.springframework.data:spring-data-jpa:jar:2.4.5:compile.
I upgraded the BOM to <spring-data-bom.version>2020.0.15</spring-data-bom.version> so I have org.springframework.data:spring-data-jpa:jar:2.4.15:compile
Once I did that it started working correctly.

Spring/JPA: composite Key find returns empty elements [{}]

I have build my data model using JPA and am using Hibernate's EntityManager to access the data. I am using this configuration for other classes and have had no problems.
The issue is that I created an entity with a composite primary key (the two keys are foreign keys) , adding elements works perfectly I checked it in database but I am not able to retrieve the populated row from database.
For example if I query "FROM Referentiel" to return a list of all referentiels in the table, I get this [{},{}] my list.size() has the proper number of elements (2), but the elements are null.
The entity:
#Entity
#Table(name = "Et_referentiel")
public class Referentiel implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
#Id
#ManyToOne
#JoinColumn(name = "id_projet")
private Projet projet;
#Id
#ManyToOne
#JoinColumn(name = "id_ressource")
private Ressource ressource;
#Column(name = "unite", nullable = false)
private String unite;
}
here is my controller getList method:
#PostMapping(value = "/list", consumes = { MediaType.APPLICATION_JSON_UTF8_VALUE })
public List<Referentiel> listReferentiel(#RequestBody Long idProjet) {
List<Referentiel> referentiel = referentielService.listReferentiel(idProjet);
return referentiel;
}
and here is my dao methods:
#Autowired
private EntityManager em;
#Override
public void ajouterReferentiel(Referentiel ref) {
em.persist(ref);
em.flush();
}
#SuppressWarnings("unchecked")
#Override
public List<Referentiel> listReferentiel(Long idProjet) {
Query query = em.createQuery("Select r from Referentiel r where r.projet.idProjet=:arg1");
query.setParameter("arg1", idProjet);
em.flush();
List<Referentiel> resultList = query.getResultList();
return resultList;
}
Any help is greatly appreciated.
Try creating a class representing your composite key:
public class ReferentielId implements Serializable {
private static final long serialVersionUID = 0L;
private Long projet; // Same type than idProjet, same name than inside Referentiel
private Long ressource; // Same type than idRessource (I guess), same name than inside Referentiel
// Constructors, getters, setters...
}
And assign it to your entity having that composite key.
#Entity
#IdClass(ReferentielId.class) // <- here
#Table(name = "Et_referentiel")
public class Referentiel implements Serializable {
// ...
}
Notice that it is required to have a class representing your composite keys, even if that does not help in your problem.

How Do I Create Many to Many Hibernate Mapping for Additional Property from the Join Table?

I need a many to many hibernate mapping needed 3 joins. I've tried to find out a solution without intermediate entity like LecturerCourse.
I have a many to many relation in my database between my lecturer and course tables. A course can be given by several lecturer while a lecturer can give several courses.
I have courses stored before hand. However, I need to assign courses to lecturer. When I assign courses I also store the capacity of that course.
My database diagram:
I use hibernate and spring. I need a hibernate mapping when a course is assign any lecturer. I need to add values to capacity field.
My lecturer mapping :
#Entity
#Table(name="LECTURER")
public class Lecturer {
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="LECTURER_ID_SEQ")
#SequenceGenerator(name="LECTURER_ID_SEQ", sequenceName="LECTURER_ID_SEQ")
private Long Id;
#Column(name="NAME")
private String name;
#Column(name="SURNAME")
private String surname;
#Column(name="EMAIL")
private String email;
#Column(name="USERNAME")
private String username;
#Column(name="PASSWORD")
private String Password;
#ManyToMany
#JoinTable(
name="LECTURER_COURSE",
joinColumns=#JoinColumn(name="LECTURER_ID"),
inverseJoinColumns=#JoinColumn(name="COURSE_ID")
)
private List<Course> courses;
//getters - setters
}
My course mapping :
#Entity
#Table(name="COURSE")
public class Course {
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="COURSE_ID_SEQ")
#SequenceGenerator(name="COURSE_ID_SEQ", sequenceName="COURSE_ID_SEQ")
private Long id;
#Column(name="NAME")
private String name;
#Column(name="CODE")
private String code;
}
Any idea how to solve my problem ?
You need to use #EmbeddedId and #Embeddable annotations to solve this issue:
Lecturer Class:
#Entity
#Table(name="LECTURER")
public class Lecturer {
#OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.lecturer", cascade=CascadeType.ALL)
Set<LecturerCourse> lecturerCourses == new HashSet<LecturerCourse>();
//all others properties Setters and getters are less relevant.
}
Course class:
#Entity
#Table(name="COURSE")
public class Course {
#OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.course", cascade=CascadeType.ALL)
Set<LecturerCourse> lecturerCourses == new HashSet<LecturerCourse>();
//all others properties Setters and getters are less relevant.
}
LecturerCourse Class:
#Entity
#Table(name = "lecturer_course")
#AssociationOverrides({
#AssociationOverride(name = "pk.lecturer",
joinColumns = #JoinColumn(name = "LECTURER_ID")),
#AssociationOverride(name = "pk.course",
joinColumns = #JoinColumn(name = "COURSE_ID")) })
public class LecturerCourse {
private LecturerCourseID pk = new LecturerCourseID();
#Column(name = "CAPACITY", nullable = false, length = 10)
private String capacity;
#EmbeddedId
public LecturerCourseID getPk() {
return pk;
}
}
Now the Primary Key:
#Embeddable
public class LecturerCourseID implements java.io.Serializable {
private Lecturer lecturer;
private Course course;
#ManyToOne
public Stock getLecturer() {
return lecturer;
}
public void setLecturer(Lecturer lecturer) {
this.lecturer= lecturer;
}
#ManyToOne
public Course getCourse() {
return course;
}
public void setCourse(Course course) {
this.course= course;
}
}
now Your Main should be something like this:
Lecturer lecturer1 = new Lecturer();
Course math = new Course();
LecturerCourse lecturer1math = new LecturerCourse();
lecturer1math.setCapacity("capacity");
lecturer1math.setLecturer(lecturer1);
lecturer1math.setCourse(math);
lecturer1.getLecturerCourses().add(lecturer1math);
//saving object
session.save(lecturer1);
You need to be sure that class marked as #Embeddable should implement Serializable marker interface.
Hope it helps.

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