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java - 保存对象后外键为空

问题描述

我有以下关系Citizen：

@Entity
@Table(name = "citizens")
public class Citizen {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@Size(max = 10, min = 10, message = "CPR must be exactly 10 characters")
private String cpr;

@OneToMany(mappedBy = "citizen", cascade = CascadeType.ALL, orphanRemoval = true)
private List<WeeklyCare> weeklyCare;
}

和WeeklyCare：

@Entity
public class WeeklyCare {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "citizen_id")
private Citizen citizen;
}

我有一个 REST API，它接收Citizen每个列表的列表WeeklyCare并保存它们：

@Autowired
private CitizenRepository citizenRepository;

@CrossOrigin(origins = "http://localhost:4200")
@PostMapping(path = "/add") // Map ONLY GET Requests
@Secured({"ROLE_ADMIN", "ROLE_DATAMANAGER"})
public ResponseEntity addNewCitizens(
        @RequestBody List<Citizen> citizens) {
    citizenRepository.saveAll(citizens);
    return new ResponseEntity(new ApiResponse(true, "Filen er blevet indlæst", "CITIZENS_SAVED"), HttpStatus.OK);
}

在此之后，当我查看weekly_care数据库中的表时，所有行的列上都为空citizen_id。我错过了什么？

标签： javahibernate

解决方案

这是一个常见的场景，Hibernate并且是由于未设置关系的倒数造成的：

Citizen c = new Citizen();
WeeklyCare w = new WeeklyCare();
c.getWeeklyCare().add(w);

//The missing link:
w.setCitizen(c);

citizenRepository.save(c);

我不确定这是如何在您的网络服务请求中配置的......

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