Java 在hibernate中添加共享主键和主键

我有两张名为Invoice and Delivery的表格

发票

invoiceId(PK)

交付

deliveryId(PK)
invoice_invoiceId(PK,FK)

这些是我用java编写的类

发票=>

@Entity(name = "invoice")
public class Invoice {
    @Id      
    @OneToOne(fetch =FetchType.LAZY,cascade = CascadeType.ALL,mappedBy = "invoice")
    private Delivery delivery;
}

public class Delivery{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @OneToOne
    @MapsId
    @Id
    @JoinColumn(name = "invoice_invoiceId",unique = true)
    private Invoice invoice;
}

@Embeddable
public class CompositeId implements Serializable{
    @Column(unique = true)
    private int deliveryId;
    @MapsId
    @OneToOne
    @JoinColumn(name = "invoiceId",unique = true)
    private Invoice invoiceId;
    //hashcode and equals methods
}

@Entity
public class Invoice {
    @Id
    private int invoiceId;
    @OneToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY,mappedBy = "compositeId.invoiceId")
    private Delivery deliveryId;
}

@Entity
public class Delivery {
    @EmbeddedId
    private CompositeId compositeId;
}

以及与之相关的getters setters

交付=>

@Entity(name = "invoice")
public class Invoice {
    @Id      
    @OneToOne(fetch =FetchType.LAZY,cascade = CascadeType.ALL,mappedBy = "invoice")
    private Delivery delivery;
}

public class Delivery{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @OneToOne
    @MapsId
    @Id
    @JoinColumn(name = "invoice_invoiceId",unique = true)
    private Invoice invoice;
}

@Embeddable
public class CompositeId implements Serializable{
    @Column(unique = true)
    private int deliveryId;
    @MapsId
    @OneToOne
    @JoinColumn(name = "invoiceId",unique = true)
    private Invoice invoiceId;
    //hashcode and equals methods
}

@Entity
public class Invoice {
    @Id
    private int invoiceId;
    @OneToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY,mappedBy = "compositeId.invoiceId")
    private Delivery deliveryId;
}

@Entity
public class Delivery {
    @EmbeddedId
    private CompositeId compositeId;
}

这就抛出了一个java.lang.NullPointerException，在这里我创建了一个会话工厂，因为我在交付类中包含了2个@Id注释

我的问题是如何使deliveryId成为PK，并使invoice（invoice\u invoiceId）成为同一个表中的共享主键？

这似乎是一个“派生标识”；但是将

invoice\u invoiceId

作为

Delivery

主键的一部分似乎有点奇怪。。。。也许你可以试试这样的东西：

public class DeliveryId implements Serializable {
    private int deliveryId; // matches the name of the attribute
    private int invoice;  // matches name of attribute and type of User PK
    ...
}

@Entity
@IdClass(DeliveryId.class)
public class Delivery {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @Id
    @OneToOne
    @JoinColumn(name = "invoice_invoiceId", unique = true)
    private Invoice invoice;
}

添加一个

@IdClass

用于

交付

需要如下：

public class DeliveryId implements Serializable {
    private int deliveryId; // matches the name of the attribute
    private int invoice;  // matches name of attribute and type of User PK
    ...
}

@Entity
@IdClass(DeliveryId.class)
public class Delivery {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @Id
    @OneToOne
    @JoinColumn(name = "invoice_invoiceId", unique = true)
    private Invoice invoice;
}

然后指定

Delivery

的

@IdClass

如下：

public class DeliveryId implements Serializable {
    private int deliveryId; // matches the name of the attribute
    private int invoice;  // matches name of attribute and type of User PK
    ...
}

@Entity
@IdClass(DeliveryId.class)
public class Delivery {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @Id
    @OneToOne
    @JoinColumn(name = "invoice_invoiceId", unique = true)
    private Invoice invoice;
}

和

Invoice.delivery

需要指定

@MapsId

注释：

@Entity
public class Invoice {
    @Id
    private int invoiceId;

    @MapsId
    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "invoice")
    private Delivery delivery;
}

---

JPA 2.1规范第2.4.1节中讨论了派生的身份（带有示例）。

我使用复合密钥解决了它

这是我的复合密钥类=>

@Entity(name = "invoice")
public class Invoice {
    @Id      
    @OneToOne(fetch =FetchType.LAZY,cascade = CascadeType.ALL,mappedBy = "invoice")
    private Delivery delivery;
}

public class Delivery{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @OneToOne
    @MapsId
    @Id
    @JoinColumn(name = "invoice_invoiceId",unique = true)
    private Invoice invoice;
}

@Embeddable
public class CompositeId implements Serializable{
    @Column(unique = true)
    private int deliveryId;
    @MapsId
    @OneToOne
    @JoinColumn(name = "invoiceId",unique = true)
    private Invoice invoiceId;
    //hashcode and equals methods
}

@Entity
public class Invoice {
    @Id
    private int invoiceId;
    @OneToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY,mappedBy = "compositeId.invoiceId")
    private Delivery deliveryId;
}

@Entity
public class Delivery {
    @EmbeddedId
    private CompositeId compositeId;
}

发票类别=>

@Entity(name = "invoice")
public class Invoice {
    @Id      
    @OneToOne(fetch =FetchType.LAZY,cascade = CascadeType.ALL,mappedBy = "invoice")
    private Delivery delivery;
}

public class Delivery{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @OneToOne
    @MapsId
    @Id
    @JoinColumn(name = "invoice_invoiceId",unique = true)
    private Invoice invoice;
}

@Embeddable
public class CompositeId implements Serializable{
    @Column(unique = true)
    private int deliveryId;
    @MapsId
    @OneToOne
    @JoinColumn(name = "invoiceId",unique = true)
    private Invoice invoiceId;
    //hashcode and equals methods
}

@Entity
public class Invoice {
    @Id
    private int invoiceId;
    @OneToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY,mappedBy = "compositeId.invoiceId")
    private Delivery deliveryId;
}

@Entity
public class Delivery {
    @EmbeddedId
    private CompositeId compositeId;
}

交付类别=>

@Entity(name = "invoice")
public class Invoice {
    @Id      
    @OneToOne(fetch =FetchType.LAZY,cascade = CascadeType.ALL,mappedBy = "invoice")
    private Delivery delivery;
}

public class Delivery{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int deliveryId;

    @OneToOne
    @MapsId
    @Id
    @JoinColumn(name = "invoice_invoiceId",unique = true)
    private Invoice invoice;
}

@Embeddable
public class CompositeId implements Serializable{
    @Column(unique = true)
    private int deliveryId;
    @MapsId
    @OneToOne
    @JoinColumn(name = "invoiceId",unique = true)
    private Invoice invoiceId;
    //hashcode and equals methods
}

@Entity
public class Invoice {
    @Id
    private int invoiceId;
    @OneToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY,mappedBy = "compositeId.invoiceId")
    private Delivery deliveryId;
}

@Entity
public class Delivery {
    @EmbeddedId
    private CompositeId compositeId;
}

因此，传送表将有自己的PK和invoiceId作为共享PK

假设我们正在将另一个共享pk添加到此传递表。所以我们也需要将其添加到CompositeId类中

---

希望这有帮助。：）

您是否尝试过

@EmbeddedId

或

IdClass

？