JPA not returning the records which contain empty columns in the EmbeddedId - spring

Question

JpaRepository's findAll() method does not return the rows, if any of the field in the composite key is null.
This is the entity class with the EmbeddedId JobVaccinationPK
/**
* ApplicationParam entity. #author MyEclipse Persistence Tools
*/
#Entity
#Table(name="job_vaccination",schema="cdcis")
#SuppressWarnings("serial")
public class JobVaccination implements java.io.Serializable {
// Fields
#Column(name="default_yn", length=1)
private String defaultYn;
#EmbeddedId
private JobVaccinationPK jobVaccinationPK;
public JobVaccination(){
}
//setters getters
}
This is the Embedded class
#Embeddable
#SuppressWarnings("serial")
public class JobVaccinationPK implements Serializable{
#ManyToOne
#MapsId("job_category_id")
#JoinColumn(name = "job_category_id", nullable=true)
private JobCategoryTypeMast jobCategoryMast;
#ManyToOne
#MapsId("vaccination_id")
#JoinColumn(name = "vaccination_id", nullable=true)
private VaccinationMast vaccinationMast;
#ManyToOne
#MapsId("screening_type_id")
#JoinColumn(name = "screening_type_id", nullable=true)
private ScreeningTypeMast screeningTypeMast;
//getters and setters
}
Service implementation class
#Override
public SearchResult<JobVaccinationDto> getJobVaccination(JobVaccinationDto dto)
throws VaccinationException {
List<JobVaccination> vaccDetails = jobVaccinationRepo.findAll();
if(vaccDetails == null) return null;
List<JobVaccinationDto> jobVaccinationDtos = new ArrayList<JobVaccinationDto>();
jobVaccinationDtos = convertToDto(vaccDetails);
return new SearchResult<>(jobVaccinationDtos.size(), jobVaccinationDtos);
}
Here am able to insert a null value for either jobCategoryId or screeningTypeId, just like below row. But when I'm trying to fetch the rows which have empty values, it returns null. I've tried to debug but I was not able to find the cause.
This is the generated hibernate query:
Hibernate:
select
jobvaccina0_.job_category_id as job_cate4_13_,
jobvaccina0_.screening_type_id as screenin2_13_,
jobvaccina0_.vaccination_id as vaccinat3_13_,
jobvaccina0_.default_yn as default_1_13_
from
cdcis.job_vaccination jobvaccina0_
Hibernate:
select
jobcategor0_.job_category_id as job_cate1_11_0_,
jobcategor0_.job_category_name as job_cate2_11_0_,
jobcategor0_.job_category_name_ar as job_cate3_11_0_,
jobcategor0_.screening_type_id as screenin4_11_0_
from
cdcis.job_category_mast jobcategor0_
where
jobcategor0_.job_category_id=?
Hibernate:
select
screeningt0_.screening_type_id as screenin1_21_0_,
screeningt0_.active_yn as active_y2_21_0_,
screeningt0_.mmpid_required_yn as mmpid_re3_21_0_,
screeningt0_.screening_type as screenin4_21_0_
from
cdcis.screening_type_mast screeningt0_
where
screeningt0_.screening_type_id=?
Hibernate:
select
vaccinatio0_.vaccination_id as vaccinat1_27_0_,
vaccinatio0_.vaccination_name as vaccinat2_27_0_,
vaccinatio0_.vaccination_name_ar as vaccinat3_27_0_
from
cdcis.vaccination_mast vaccinatio0_
where
vaccinatio0_.vaccination_id=?
Going with #Adam Michalik answer. As a work-around I've introduced a new primary key field in the table, as we can't handle a null in the composite key.

Answer 1

Composite IDs cannot contain null values in any of the fields. Since the SQL semantics of NULL is that NULL <> NULL, it cannot be determined that a primary key (1, 2, NULL) is equal to (1, 2, NULL).
NULL means "no value" in SQL and its interpretation is up to you on a case-by-case basis. That's why SQL and JPA do not want to make assumptions that NULL = NULL and that a primary key containing a NULL identifies a single entity only.
You may choose to use a synthetic, generated primary key instead of the composite business primary key to overcome that. Then, you'd always have a non-null, single-column PK and nullable foreign keys.

Answer 2

change the data type of particular row in entity from int to integer