java为什么Hibernate会在更新期间将json中的空id传递给子实体时插入新记录
我有最新消息。波乔斯:我把它简化了
public class CaseOutlineHeader{
@Id
@GeneratedValue(generator = "COH_SequenceStyleGenerator")
@Column(name = "outline_id")
private Long id;
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "outline_id", nullable = true, referencedColumnName = "outline_id",
foreignKey = @ForeignKey(name = "FK_COH_REF_COD_01"))
private List<CaseOutlineDetails> caseOutlineDetails;
}
public class CaseOutlineDetails{
@Id
@GeneratedValue(generator = "COD_SequenceStyleGenerator")
@Column(name = "ID")
private Long id;
@ManyToOne(targetEntity = MaintCaseEvent.class)
@JoinColumn(name = "EVENT_ID", nullable = false,
foreignKey = @ForeignKey(name = "FK_COD_REF_CASE_EVENT"),
referencedColumnName = "CASE_EVENT_ID")
private MaintCaseEvent eventId;
@Column(name = "outline_id")
private Long outlineId;
}
然后是我的服务:如果传递的COD的json包含不为null的id,它将随COD一起更新COH,这非常简单。否则,如果我传递了一个空的COD id,我将在COD中另存为一个新条目
@Override
@Transactional
public CaseOutlineHeader update(CaseOutlineHeader caseoutline) {
LOG.info("SERVICE: Updating CaseOutlineHeader...{}", caseoutline);
if (!CollectionUtils.isEmpty(caseoutline.getCaseOutlineDetails())) {
caseoutline.getCaseOutlineDetails().forEach(cod -> {
if (cod.getId() != null) {
cod.setUpdatedBy(cod.getUpdatedBy());
cod.setUpdatedDate(new Date());
caseOutlineHeaderRepository.update(caseoutline);
} else {
cod.setOutlineId(caseoutline.getId());
cod.setCreatedBy("dwade");
caseOutlineDetailsRepository.save(cod);
}
});
}
return caseoutline;
}
以虚张声势传递json数据:
{
"id": 1,
"caseOutlineDetails": [
{
"eventId": { "id": 1 },
"updatedBy": "kobe",
"id" : 1,
"outlineId" : 1
},
{
"eventId": { "id": 2},
"outlineId" : 1
}
],
"caseType": "string",
"code": "updateC",
"description": "updateD",
"updatedBy": "kobe",
"updatedDate": "2018-07-23T00:55:16.767Z"
}
正如您所见,我在COD中传递了第二个数据,该数据没有id属性,它将被保存。而第一个将被更新,其中包含一个id
这是我的回购协议:
@Override
public CaseOutlineHeader update(CaseOutlineHeader caseOutlineHeader) {
em.merge(caseOutlineHeader);
em.flush();
return caseOutlineHeader;
}
@Override
public CaseOutlineDetails save(CaseOutlineDetails caseOutlineDetails) {
LOG.info("REPOSITORY : SAVE = " + caseOutlineDetails);
em.persist(caseOutlineDetails);
return caseOutlineDetails;
}
但在我的记录器中,我不知道为什么它首先插入一个新记录,其中id和外键仅作为值。但insert语句的最后一行是成功的
Hibernate: insert into case_outline_details (access_level...
Hibernate: update case_outline_header set access_level=?...
Hibernate: update case_outline_details set access_level=?...
Hibernate: select seq_cod.nextval from dual
Hibernate: insert into case_outline_details (access_level...
它应该是更新,更新,然后插入
# 1 楼答案
实体实例,并使用 来自此分离实例的新值
的现有实体实例 检索持久性上下文,或从
加载新实例 数据库);将字段从传递的对象复制到此
例子返回新更新的实例。
# 2 楼答案
您用
cascade = CascadeType.ALL
声明了caseOutlineDetails
。因此,当您更新CaseOutlineHeader
时,hibernate将自动更新列表,并在需要时插入行。然后你做你的东西,然后再插入它