java - Hibernate OneToMany 关联表字段对于repository.save(entityModel) 不能为空

Question

有两个实体Policy和PolicyDetails。 Policy.id 与PolicyDetails.policyId 一对多关联。喜欢

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name = "policy_id", referencedColumnName = "id")
private List<PolicyDetails> policyDetails;

当我获取数据时一切正常。但我运行policyRepository.save(policy)抛出以下错误-

Hibernate:更新策略集category_id=？、category_name=？、client_id=？、summary=？哪里 id=?Hibernate:更新policy_details设置policy_id=null，其中policy_id=？和id=？Hibernate:更新policy_details设置policy_id=null，其中policy_id=？和id=？

由以下原因引起:java.sql.BatchUpdateException:列“policy_id”不能为空引起原因:java.sql.SQLIntegrityConstraintViolationException:列“policy_id”不能为空

@Entity
@Data
@Table(name = DBTables.POLICY)
public class Policy implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false, updatable = false)
    private Integer Id;

    @Column(name = "summary")
    @NotNull(message = ErrorCode.SUMMARY_NOT_FOUND)
    private String summary;

    @Column(name = "category_id")
    @NotNull(message = ErrorCode.CATEGORY_ID_NOT_FOUND)
    private Integer categoryId;

    @Column(name = "category_name")
    @NotNull(message = ErrorCode.CATEGORY_NAME_NOT_FOUND)
    private String categoryName;

    @Column(name = "client_id")
    @NotNull(message = ErrorCode.CLIENT_ID_NOT_FOUND)
    private Integer clientId;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumn(name = "policy_id", referencedColumnName = "id")
    private List<PolicyDetails> policyDetails;
}

@Entity
@Data
@Table(name = DBTables.POLICY_DETAILS)
public class PolicyDetails implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false, updatable = false)
    private Integer id;

    @Column(name = "policy_id")
    @NotNull(message = ErrorCode.POLICY_ID_NOT_FOUND)
    private Integer policyId;

    @Column(name = "period")
    @NotNull(message = ErrorCode.PERIOD_NOT_FOUND)
    private String period;

    @Column(name = "logic_id")
    @NotNull(message = ErrorCode.LOGIC_ID_NOT_FOUND)
    private Integer logicId;

    @Column(name = "logic_value")
    @NotNull(message = ErrorCode.LOGIC_VALUE_NOT_FOUND)
    private Integer logicValue;

    @Column(name = "policy_type_id")
    @NotNull(message = ErrorCode.POLICY_TYPE_ID_NOT_FOUND)
    private Integer policyTypeId;
}

    public String saveRegisterPolicy(PolicyRequestDto policyRequestDto, Integer userId) {

        Policy policy = new Policy();

        policy.setId(policyRequestDto.getId());
        policy.setSummary(policyRequestDto.getSummary());
        policy.setCategoryId(policyRequestDto.getCategoryId());
        policy.setCategoryName(policyRequestDto.getCategoryName());
        policy.setClientId(userId);

        List<PolicyDetails> policyDetails = new ArrayList<>();
        policyDetails.addAll(policyRequestDto.getCancelPolicies());
        policyDetails.addAll(policyRequestDto.getDelayPolicies());

        policyDetails.forEach(eachPolicyDetails ->
            eachPolicyDetails.setPolicyId(policyRequestDto.getId())
        );

        policy.setPolicyDetails(policyDetails);

        policyRepository.save(policy);


        return null;
    }

Answer 1

你非常接近，但是，你的映射有点错误。在hibernate中，我们必须有用于映射的对象(而不是id)。为了可用性和速度，建议这种关系是双向的。在某些情况下，Hibernate 会通过单向多对一和一对多关系创建尴尬的查询。

    @NotNull(message = ErrorCode.POLICY_ID_NOT_FOUND)
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "policy_id", referencedColumnName = "id", nullable = false)
    private Policy policy;

因此，将您的 PolicyDetails 更改为:

@Entity
@Data
@Table(name = DBTables.POLICY_DETAILS)
public class PolicyDetails implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false, updatable = false)
    private Integer id;

    @NotNull(message = ErrorCode.POLICY_ID_NOT_FOUND)
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "policy_id", referencedColumnName = "id", nullable = false)
    private Policy policy;

    @Column(name = "period")
    @NotNull(message = ErrorCode.PERIOD_NOT_FOUND)
    private String period;

    @Column(name = "logic_id")
    @NotNull(message = ErrorCode.LOGIC_ID_NOT_FOUND)
    private Integer logicId;

    @Column(name = "logic_value")
    @NotNull(message = ErrorCode.LOGIC_VALUE_NOT_FOUND)
    private Integer logicValue;

    @Column(name = "policy_type_id")
    @NotNull(message = ErrorCode.POLICY_TYPE_ID_NOT_FOUND)
    private Integer policyTypeId;
}