JPA：如何覆蓋@Embedded屬性的列名

Question

Person

@Embeddable
public class Person {
    @Column
    public int code;

    //...
}

作為兩個不同的屬性，在Event嵌入了兩次： manager和operator

@Entity
public class Event {
    @Embedded
    @Column(name = "manager_code")
    public Person manager;

    @Embedded
    @Column(name = "operator_code")
    public Person operator;

    //...
}

在使用Persistence生成數據庫模式時，這應該給出兩個相應的列。 而是拋出異常：

org.hibernate.MappingException：實體映射中的重復列：事件列：代碼

如何覆蓋每個屬性的默認列名稱code ？

Answer 1

使用@AttributeOverride ，這是一個例子

@Embeddable public class Address {
    protected String street;
    protected String city;
    protected String state;
    @Embedded protected Zipcode zipcode;
}

@Embeddable public class Zipcode {
    protected String zip;
    protected String plusFour;
}

@Entity public class Customer {
    @Id protected Integer id;
    protected String name;
    @AttributeOverrides({
        @AttributeOverride(name="state",
                           column=@Column(name="ADDR_STATE")),
        @AttributeOverride(name="zipcode.zip",
                           column=@Column(name="ADDR_ZIP"))
    })
    @Embedded protected Address address;
    ...
}

在你的情況下，它看起來像這樣

@Entity
public class Event {
    @Embedded
    @AttributeOverride(name="code", column=@Column(name="manager_code"))
    public Person manager;

    @Embedded
    @AttributeOverride(name="code", column=@Column(name="operator_code"))
    public Person operator;

    //...
}