我必须使用多对一的双向关系定义 JPA 实体,特此:
@Entity
public class Department implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@SequenceGenerator(name="DEPARTAMENTO_ID_GENERATOR",sequenceName="DEPARTAMENTO_SEQ")
@GeneratedValue(strategy=GenerationType.SEQUENCE,generator="DEPARTAMENTO_ID_GENERATOR")
@Column(name="DEP_ID")
private long id;
@Column(name="DEP_DESC")
private String desc;
//bi-directional many-to-one association to Academico
@OneToMany(mappedBy="department")
private Set<Proffesor> proffesors;
//getters and setters
}
@Entity
@Table(name="ACADEMICOS")
public class Proffesor implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@SequenceGenerator(name="ACADEMICOS_ID_GENERATOR", sequenceName="ACADEMICOS_SEQ")
@GeneratedValue(strategy=GenerationType.SEQUENCE,generator="ACADEMICOS_ID_GENERATOR")
@Column(name="ACD_ID")
private long id;
@ManyToOne(cascade={CascadeType.PERSIST,CascadeType.MERGE})
@JoinColumn(name="ACD_DEPADSCRITO_DEP")
private Department department;
// getters and setters.
}
在事务性 Spring 服务之后,我有下一个代码来以这种方式操作实体。
@Transactional (propagation=Propagation.REQUIRED)
public void createDepartmentWithExistentProffesor(String desc,Long idAvaiableProf) {
// new department
Department dep = new Department();
dep.setDesc(desc);
HashSet<Proffesor> proffesors = new HashSet<Proffesor>();
dep.setProffesors(proffesors);
// I obtain the correct attached Proffesor entity
Proffesor proffesor=DAOQueryBasic.getProffesorById(idAvaiableProf);
// I asign the relationship beetwen proffesor and department in both directions
dep.addProffesors(proffesor);
// Persists department
DAODataBasic.insertDepartment(dep);
// The id value is not correct then Exception ORA-0221
System.out.println("SERVICIO: Departamento creado con id: " + dep.getId());
}
正如我在评论中所说,持久化的新部门的ID不是事务中的真实数据库ID,那么它就会产生异常
Exception in thread "main" org.springframework.orm.jpa.JpaSystemException: org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
........
Caused by: java.sql.BatchUpdateException: ORA-02291: integrity restiction (HIBERNATE_PRB.FK_ACD2DEP) violated - primary key don't found
我在测试中尝试过,持久化与 Proffesor 没有关系的新部门实体,我发现新部门持久化实体的 id 在事务中没有有效值,但在事务之外,id 已经有正确的值。但我需要交易中的正确值。
有谁能够帮我?先感谢您。