Java – hibernate criteriabuilder connects multiple tables

I'm trying to add four tables using hibernate criteriabuilder

@Entity
public class BuildDetails {
    @Id
    private long id;
    @Column
    private String buildNumber; 
    @Column
    private String buildDuration;
    @Column
    private String projectName;

}   

@Entity
public class CodeQualityDetails{
    @Id
    private long id;
    @Column
    private String codeHealth;
    @ManyToOne
    private BuildDetails build; //columnName=buildNum
}

@Entity
public class DeploymentDetails{
    @Id
    private Long id;
    @Column
    private String deployedEnv;
    @ManyToOne
    private BuildDetails build; //columnName=buildNum
}

@Entity
public class TestDetails{
    @Id
    private Long id;
    @Column
    private String testStatus;
    @ManyToOne
    private BuildDetails build; //columnName=buildNum
}

In these four tables, I want to execute the following SQL script for MySQL:

SELECT b.buildNumber,b.buildDuration,c.codeHealth,d.deployedEnv,t.testStatus
FROM BuildDetails b
INNER JOIN CodeQualityDetails c ON b.buildNumber=c.buildNum
INNER JOIN DeploymentDetails d ON b.buildNumber=d.buildNum
INNER JOIN TestDetails t ON b.buildNumber=t.buildNum
WHERE b.buildNumber='1.0.0.1' AND
      b.projectName='Tera'

So how do I use hibernate criteriabuilder to achieve this goal? Please help

Thank you in advance

Solution

CriteriaBuilder cb = entityManager.getCriteriaBuilder();

CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery query = cb.createQuery(/* Your combined target type,e.g. MyQueriedBuildDetails.class,containing buildNumber,duration,code health,etc.*/);

Root<BuildDetails> buildDetailsTable = query.from(BuildDetails.class);
Join<BuildDetails,CopyQualityDetails> qualityJoin = buildDetailsTable.join(CopyQualityDetails_.build,JoinType.INNER);
Join<BuildDetails,DeploymentDetails> deploymentJoin = buildDetailsTable.join(DeploymentDetails_.build,TestDetails> testJoin = buildDetailsTable.join(TestDetails_.build,JoinType.INNER);

List<Predicate> predicates = new ArrayList<>();
predicates.add(cb.equal(BuildDetails_.buildNumber,"1.0.0.1"));
predicates.add(cb.equal(BuildDetails_.projectName,"Tera"));

query.multiselect(buildDetails.get(BuildDetails_.buildNumber),buildDetails.get(BuildDetails_.buildDuration),qualityJoin.get(CodeQualityDetails_.codeHealth),deploymentJoin.get(DeploymentDetails_.deployedEnv),testJoin.get(TestDetails_.testStatus));
query.where(predicates.stream().toArray(Predicate[]::new));

TypedQuery<MyQueriedBuildDetails> typedQuery = entityManager.createQuery(query);

List<MyQueriedBuildDetails> resultList = typedQuery.getResultList();

I suppose you build a JPA Metamodel for your class If you don't have a metamodel or you don't want to use it at all, just put build details_ Replace buildnumber with the rest, and replace the actual name of the column with string, for example: "buildnumber"

Please note that I can't test the answer (also write it without editor support), but it should contain at least everything I need to know to build the query

How to build a meta model? Check out hibernate tooling (or other alternatives, please consult how to generate JPA 2.0 metamodel?) If you are using maven, it is as simple as adding hibernate JPA model Gen dependency to the build classpath Because I don't have any such projects now, I'm not sure about the following contents (so please wait a minute) It may be sufficient to add the following as dependencies:

<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-jpamodelgen</artifactId>
  <version>5.3.7.Final</version>
  <scope>provided</scope> <!-- this might ensure that you do not package it,but that it is otherwise available; untested Now,but I think I used it that way in the past -->
</dependency>