我尝试以一对多关系保留父实体:
@Entity
public class TrainEx {
private Set<TrainCompositionEx> trainCompositionsByTrainId;
@OneToMany(cascade = {CascadeType.ALL}, fetch = FetchType.LAZY, mappedBy = "trainByTrainId")
public Set<TrainCompositionEx> getTrainCompositionsByTrainId() {
return trainCompositionsByTrainId;
}
public void setTrainCompositionsByTrainId(Set<TrainCompositionEx> trainCompositionsByTrainId) {
this.trainCompositionsByTrainId = trainCompositionsByTrainId;
}
...
}
和子实体:
@Entity
public class TrainCompositionEx{
@Id
@ManyToOne(cascade = {CascadeType.REFRESH}, fetch = FetchType.LAZY)
@JoinColumn(name = "trainId", referencedColumnName = "trainId", nullable = false, insertable = true, updatable = true)
private TrainEx trainByTrainId;
....
}
所以我从json POST端点收到了TrainEx trainEx:
@RequestMapping(method= RequestMethod.POST, consumes = "application/json", produces = "application/json")
public @ResponseBody
ResponseEntity<Void> addTrain(@RequestBody TrainEx trainEx) throws Exception {
trainService.add(trainEx);
return new ResponseEntity<Void>(HttpStatus.CREATED);
}
json:
{
"trainId" : 5,
"status" : 1,
"maxWeight" : 200,
"maxLength" : 35,
"speed" : 60,
"totalWeight" : 100,
"totalLength" : 20,
"trainCompositionsByTrainId": [{
"wagonByWagonId": {"wagonId" : 2}
}]
}
在我这样保存之后:
...
@Transactional
public TrainEx add(TrainEx trainEx) {
for(TrainCompositionEx trainCompositionEx : trainEx.getTrainCompositionsByTrainId()){
trainCompositionEx.setTrainByTrainId(trainEx);
trainCompositionEx.setWagonByWagonId(
em.getReference(WagonEx.class, trainCompositionEx.getWagonByWagonId().getWagonId()));
}
return trainExRepository.save(trainEx);
}
...
但是我收到了SQL错误:“trainid”列中的null值违反了非null约束,但是如您所见,我将trainEx实体设置为TrainCompositionEx,并且在调试模式下停止运行,并且trainId在那里存在:
所以我该怎么做?
UPDATE1:
我调查了日志,认为那个孩子的问题在父实体之前仍然存在,因为我插入了train_composition表,但没有插入train表,请参见:
Hibernate: insert into tms.public.train_composition (version, transportOrderId, wagonId, trainId) values (?, ?, ?, ?)
最佳答案
我使用em.persist
持久化类。我的上级实体有
@JsonProperty(TIMES)
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
private Set<Times> timesList = new HashSet<Times>();
当孩子有
@JsonIgnore
@ManyToOne(cascade = CascadeType.ALL)
private Rider rider;
该代码是
em.persist(rider);
for (Times t : rider.getTimes()) {
t.setRider(rider);
}
对于新手,对于现有手,我将新数据合并到旧对象中。
该项目在这里:https://github.com/xtien/motogymkhana-server
该代码来自
RiderDaoImpl
,Rider
和Times
。这是项目的目的:http://www.gymcomp.com/eu
关于java - SPRING DATA JPA保存@OneToMany关系,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/36163310/