Question

我有这些课程：

@Entity
@Table(name = "branch", uniqueConstraints = {@UniqueConstraint(columnNames = {"bname", "branch_fk"})})
public class BranchEntity implements Serializable {

    @Id
    @GeneratedValue
    private int id;
    @Column(name = "username", length = 64, nullable = false)
    private String userName;
    @Column(name = "bname", length = 64)
    private String branchName;
    @Column(name = "studcount")
    private int studCount;
    @Column(name = "blevel", columnDefinition = "int default 0")
    private int level;
    @Column(name = "confirmed", columnDefinition = "tinyint default 0")
    private int confirmed;
    @OneToMany(mappedBy = "branch", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @OnDelete(action = OnDeleteAction.CASCADE)
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
    private Set<BranchBuildingEntity> branchbuilding = new HashSet<BranchBuildingEntity>();
    @OneToMany(mappedBy = "branch", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @OnDelete(action = OnDeleteAction.CASCADE)
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
    private Set<PictureEntity> picture = new HashSet<PictureEntity>();
    @OneToOne(mappedBy = "branch", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @OnDelete(action = OnDeleteAction.CASCADE)
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
    private LoginEntity login;
    @OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)    
    @JoinColumn(name = "human_fk", nullable = true)
    private HumanEntity human;
//some setter and getter

正如您所看到的，这些表与HumnEntity和PictureEntity以及...表有关系。在我的域层中，我有Branch类，它依赖于Branch表及其所有关系。当域传递一个分支对象，我想要更改数据库中的分支我有一些问题，解释如下。在Human类的Domain Layer中我没有Identifier（主键）然后当我想要SaveOrUpdate（branchEntity）时我必须设置所有属性但是当我想设置branchEntity.setHumanEntity时我必须再次查询并从数据库获取Identifier并设置为humanEntity然后设置branchEntity.setHumanEntity。我想知道那是对的吗？或者我错了一些在哪里？我必须在域层中的Human Human类中保留HumanEntity Identifier吗？实际上我不知道保存或SaveOrUpdate或更新或者与其他对象具有RElation的对象时到底发生了什么？我该如何处理该对象？

Answer 1

让我说出我的确切问题当我想要更改我的表格分支时，我使用此branchDao.update(be);

但是通过这段代码我有错误：

pkId = branch.getId();
        uname = branch.getUsername();
        password = branch.getPassword();
        bname = branch.getName();
        studentCount = branch.getStudentNum();
        level = branch.getLevel();
        otherBuilding = branch.getOtherBuildings();
        ofname = branch.getBoss().getFirstName();
        olname = branch.getBoss().getLastName();
        oemail = branch.getBoss().getEmail();
        HumanEntity he =  humanDao.getBossByProperties(oemail);
        BranchEntity be = new BranchEntity();
        be.setHuman(he);
        be.setId(pkId);
        be.setBranchName(bname);
        be.setConfirmed(confirmed);
        be.setLevel(level);
        be.setStudCount(studentCount);
        be.setUserName(uname);            
        branchDao.update(be);

当我发表评论be.setHuman(he);时，它更新了分支，但在human_fk上放了空！当dun评论发生此错误时：用另一个带有此标识符的对象表示存在。我必须首先删除所有相关的Object to Branch然后重新设置它们吗？

Hibernate保存对象问题

1 个答案: