1 Reply Latest reply on May 8, 2006 12:09 PM by cyril.joui

Multiple PK, one from joined column

elvisd May 5, 2006 5:55 PM

Hi all,

I have this situation:
2 entities, country and state
country has code and name as fields, code is PK
state has code, name and country_code (linked to country code field) as fields, code is PK and country_code should too.

@Entity @Table(name="country")
class Country implements Serializable{
@Id @Column(name="code",length=2)
private String code;
@Column(name="name",length=50)
private String name;

//setters and getters here
}

then

@Entity @Table(name="state")
class State implements Serializable{
@Id @Column(name="code",length=2)
private String state;
@Column(length=50)
private String name;
@ManyToOne
@JoinColumn(name = "countryCode", nullable = false)
private Country country; //<-- should be PK too!!!
//setters and getters here
}

Can someone help me to understand this?
Thank you all in advance

1. Re: Multiple PK, one from joined column

cyril.joui May 8, 2006 12:09 PM (in response to elvisd)

Here is an example :

With Order / OrderPK / OrderLine (=> has a composite primary key with 2 foreign keys)

@Entity
@Table(name="ORDERS")
public class Order {

 private int id;

 private Date orderDate;

 @Id
 @GeneratedValue(strategy=GenerationType.AUTO)
 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 public Date getOrderDate() {
 return orderDate;
 }

 public void setOrderDate(Date orderDate) {
 this.orderDate = orderDate;
 }
}


@Entity
@IdClass(OrderLinePk.class)
public class OrderLine {

 private Product product;

 private Order order;

 private int quantity;

 public OrderLine() {
 }

 public int getQuantity() {
 return quantity;
 }

 public void setQuantity(int quantity) {
 this.quantity = quantity;
 }

 @ManyToOne
 @JoinColumn(name="orderId", insertable=false, updatable=false)
 public Order getOrder() {
 return order;
 }

 public void setOrder(Order order) {
 this.order = order;
 }

 @ManyToOne
 @JoinColumn(name="productId", insertable=false, updatable=false)
 public Product getProduct() {
 return product;
 }

 public void setProduct(Product product) {
 this.product = product;
 }

 @Id
 public int getProductId() {
 return getProduct().getId();
 }

 @Id
 public int getOrderId() {
 return getOrder().getId();
 }

 public void setOrderId(int orderId) {
 getOrder().setId(orderId);
 }

 public void setProductId(int productId) {
 getProduct().setId(productId);
 }

}


@Embeddable
public class OrderLinePk implements Serializable {

 private static final long serialVersionUID = 1L;

 private int orderId;

 private int productId;

 protected OrderLinePk() {
 }

 public OrderLinePk(int orderId, int productId) {
 this.orderId = orderId;
 this.productId = productId;
 }

 public int getOrderId() {
 return orderId;
 }

 public void setOrderId(int orderId) {
 this.orderId = orderId;
 }

 public int getProductId() {
 return productId;
 }

 public void setProductId(int productId) {
 this.productId = productId;
 }

}

Hope it would be useful.