java - @OneToOne 单向映射中的实体映射中的重复列

Question

考虑以下数据库结构

我需要像这样实现单向一对一映射(结构已简化):

@Entity
@Table(name = "entity")
public class Customer {

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

    @OneToOne
    @JoinColumn(name = "customer_info", nullable = false)
    private CustomerInfo customerInfo;

    @OneToOne
    @JoinColumn(name = "customer_credentials", nullable = false)
    private CustomerCredentials customerCredentials;

    //  getter, setters etc
}

@Entity
@Table(name = "customer_info")
public class CustomerInfo {

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

    //  getter, setters etc
}

@Entity
@Table(name = "customer_credentials")
public class CustomerCredentials {

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

    //  getter, setters etc
}

但不知何故，hibernate 无法区分这些连接来自不同的表并抛出这样的错误:

Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: com.example.Customer column: customer_id (should be mapped with insert="false" update="false")

重要通知:我不想使用@OneToOne(mappedBy = "customer")，因为我需要级联保存功能

Answer 1

您可以使用@JoinTable代替@JoinColumn来解决您的问题:

@Entity @Table(name = "entity") public class Customer {

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

    @OneToOne(cascade = CascadeType.ALL, targetEntity = CustomerInfo.class)
    @JoinTable(name = "customer_info", inverseJoinColumns = {@JoinColumn(name = "customer_id", nullable = false)})
    private CustomerInfo customerInfo;

    @OneToOne(cascade = CascadeType.ALL, targetEntity = CustomerCredentials.class)
    @JoinTable(name = "customer_credentials", inverseJoinColumns = {@JoinColumn(name = "customer_id", nullable = false)})
    private CustomerCredentials customerCredentials;

    //  getter, setters etc }

@Entity @Table(name = "customer_info") public class CustomerInfo {

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

    //  getter, setters etc }

@Entity @Table(name = "customer_credentials") public class CustomerCredentials {

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

    //  getter, setters etc }

您可以将级联策略更改为您需要的任何策略。我只是将 CascadeType.ALL 留在那里作为示例。