java - 我正在 hibernate 状态下保存一个实体。它正在更新同一语句中已保存的数据。如何解决这个问题？

Question

我有两个实体父实体和子实体:
Group_Email_History.java(父级)

@Entity
@Table(name = "Group_Email_History")
public class Group_Email_History implements Serializable, Cloneable{

@Id
@GeneratedValue()
@Column(name = "ID")
private Integer id;

@ManyToOne
@JoinColumn(name = "GroupId", nullable = false)
private Groups groups;

@OneToMany(cascade=CascadeType.ALL,fetch = FetchType.EAGER)
@JoinColumn(name="GROUP_EMAIL_HISTORY_ID",nullable=true)
@JsonIgnore
private Set<AttachmentInfo> attachmentInfo = new HashSet<AttachmentInfo>(0);



@ManyToOne
@JoinColumn(name = "UserId", nullable = false)
private Users users;

@NotEmpty

@Column(name = "EmailId")
private String emailId;

@Column(name = "Subject")
private String subject;

@Column(name = "EmailText")
private String emailText;
@NotEmpty

@Column(name = "EmailSentDate")
private String emailSentDate;

@Column(name = "isEmailSent")
private boolean isEmailSent;


@Transient
private String attachedFileName;

@Transient
private List<MultipartFile> alist;
//setters and getters  

AttachmentInfo.java(子):

@Entity
@Table(name="AttachmentInfo")
public class AttachmentInfo implements Serializable{
/**
 * 
 */
private static final long serialVersionUID = 1L;

@Id
@GeneratedValue
private Integer attachment_Id;

@Column(name="attachedFileName")
private String attachedFileName;

@Column(name="attachedFileSize")
private Long attachedFileSize;

@Column(name="attachedFile")
@Lob
private byte[] attachedFile;


@Column(name="attachedFileType")
private String attachedFileType;


@Transient
private String attachedFilePath;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "UserId", nullable = false)
private Users users;



@ManyToOne(fetch=FetchType.EAGER,cascade = CascadeType.ALL)
@JoinColumn(name = "GROUP_EMAIL_HISTORY_ID",nullable=true,insertable=false,updatable=false)
private Group_Email_History group_Email_History;


@ManyToOne(fetch=FetchType.EAGER,cascade = CascadeType.ALL)
@JoinColumn(name = "SCHEDULE_ID",nullable=true)
private Schedule_Email schedule_Email;

现在我正在保存父实体..它还将通过调用来保存子实体:

sessionFactory.getCurrentSession().save(parent);

调用上面的 save() 后，控制台是:

我正在附件表中保存多个附件..
但问题是附件表具有 groupemailhisory 表主键，例如:

attachment_id    group_email_history_id    ........
1                            1             ........etc  

首先将 group_email_history_id 更新为 1。
之后 save() 调用 group_email_history_id 值并将其更新为对象中可用的最新值。即

attachment_id    group_email_history_id    ........  
1                         2                ........
2                         2                ........

注意:如果在一次 save() 内将多个 group_email_history_id 保存在 group_Email_History 表中，就会发生这种情况。
如何解决这个问题？请帮助我......

我的 Controller 代码是:

@RequestMapping(value= "/groupEmail",method = RequestMethod.POST)
public String doGroupEmail(@ModelAttribute("email") @Valid  Group_Email_History email,BindingResult result) {
  try{
    //date object creation
    Date date = new Date();
    //formating the date
    SimpleDateFormat df2 = new SimpleDateFormat("dd/MMM/yyyy HH:mm");
    String formattedDate = df2.format(date);
    email.setEmailSentDate(formattedDate);

    HashSet<AttachmentInfo> hs = new HashSet<AttachmentInfo>();

    List<MultipartFile> alist = files;

    long size =0;






    // creates Mime message Object
    MimeMessage message = mailSender.createMimeMessage();
    MimeMessageHelper messageHelper = new MimeMessageHelper(message, true,"UTF-8");

    messageHelper.setSubject(email.getSubject());
    messageHelper.setText(email.getEmailText());

    String[] emailids = email.getEmailId().split(",");

    //iterating for mail Ids
    for(MultipartFile mpf : alist){
        final MultipartFile mp = mpf;
        size+=mp.getSize();

         InputStreamSource iss = new InputStreamSource() {
             @Override
             public InputStream getInputStream() throws IOException {
                 // provide fresh InputStream
                 return mp.getInputStream();
             }
         };
         messageHelper.addAttachment(mp.getOriginalFilename(), iss);
    }
    for(String mailid : emailids)
    {

        if(mailid != ""){
            final Integer userid = iGroupEmailService.getUserId(mailid);

            for(MultipartFile mpf : alist){
                final MultipartFile mp = mpf;
                size+=mp.getSize();


                hs.add(new AttachmentInfo(){

                {
                    setAttachedFile(mp.getBytes());
                    setAttachedFileName(mp.getOriginalFilename());
                    setAttachedFileSize(mp.getSize());
                    setAttachedFileType(mp.getContentType());
                    setUsers(new Users(){{
                        setUserId(userid);
                    }});

                }});
            }
            email.setAttachmentInfo(hs);
        Group_Email_History  email2 = (Group_Email_History)email.clone();
        email2.setEmailId(mailid);
        email2.setUsers(new Users(){{
            setUserId(userid);
        }});

        iGroupEmailService.saveEmailSendingInformation(email2);

        messageHelper.setTo(mailid);
     // sends the e-mail
        mailSender.send(message);
        }

    }

Answer 1

首先，我发现理解你的帖子确实有问题。不过，据我所知，您在不需要的更新语句方面遇到了一些麻烦。您应该尝试更改这部分:

@OneToMany(cascade=CascadeType.ALL,fetch = FetchType.EAGER)
@JoinColumn(name="GROUP_EMAIL_HISTORY_ID",nullable=true)
@JsonIgnore
private Set<AttachmentInfo> attachmentInfo = new HashSet<AttachmentInfo>(0);

进入此:

@OneToMany(mappedBy = group_Email_History, cascade=CascadeType.ALL,
           fetch = FetchType.EAGER)
@JsonIgnore
private Set<AttachmentInfo> attachmentInfo = new HashSet<AttachmentInfo>(0);

因此，在子实体上，您的代码应如下所示:

@ManyToOne(fetch=FetchType.EAGER,cascade = CascadeType.ALL)
@JoinColumn(name = "GROUP_EMAIL_HISTORY_ID",nullable=true)
private Group_Email_History group_Email_History;

@ManyToOne 通常是关系的所有者，并用 @JoinColumn 进行注释。因此，@OneToMany 获取 mappedBy 属性。了解更多 here .

负责持久化的代码应如下所示:

attachmentInfo.add(attachement1);
attachmentInfo.add(attachement2);
group_Email_History.setAttachementInfo(attachmentInfo);
attachement1.setGroup_Email_History(group_Email_History);
attachement2.setGroup_Email_History(group_Email_History);
...
sessionFactory.getCurrentSession().save(group_Email_History);

编辑:尝试更改这部分:

hs.add(new AttachmentInfo(){
{
    //you need to set Group_Email_History object 
    //to every AttachmentInfo Object as well
    setGroup_Email_History(email);

    setAttachedFile(mp.getBytes());
    setAttachedFileName(mp.getOriginalFilename());
    setAttachedFileSize(mp.getSize());
    setAttachedFileType(mp.getContentType());
    setUsers(new Users(){{
    setUserId(userid);
}});
}});