休眠复合键ID生成器

Question

我的实体如下。我的数据模型在下面强制执行，因此我无法更改引用的完整性。因此，我陷入了复合键的困境。我想自动生成/使用一些生成器作为orderId

是的，我已经阅读以下内容。
http://docs.jboss.org/hibernate/annotations/3.5/reference/en/html_single/#entity-
mapping-
identifier

我不想管理id生成过程，因为上面建议应用程序生成orderId。

如何使部分ID生成器工作..我有什么选择..非常感谢专家的一些想法。

@Entity
@Table(name = "Orders", uniqueConstraints = @UniqueConstraint(columnNames = {"partner_ID", "order_ident" }))
public class Order  {

private OrderId id;

public Order() {
}


@EmbeddedId
@AttributeOverrides({
        @AttributeOverride(name = "partnerId", column = @Column(name = "partner_ID", nullable = false)),
        @AttributeOverride(name = "employeeId", column = @Column(name = "employee_ID", nullable = false)),
        @AttributeOverride(name = "orderId", column = @Column(name = "order_ID", nullable = false)) })
public OrderId getId() {
    return this.id;
}

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


}


@Embeddable
public class OrderId extends FactObject {

private int partnerId;
private int employeeId;
private int orderId;

public OrderId() {
}

public OrderId(int partnerId, int employeeId, int orderId) {
    this.partnerId = partnerId;
    this.employeeId = employeeId;
    this.orderId = orderId;
}

@Column(name = "partner_ID", nullable = false)
public int getpartnerId() {
    return this.partnerId;
}

public void setpartnerId(int partnerId) {
    this.partnerId = partnerId;
}

@Column(name = "employee_ID", nullable = false)
public int getemployeeId() {
    return this.employeeId;
}

public void setemployeeId(int employeeId) {
    this.employeeId = employeeId;
}

@Id @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="SEQ_STORE")
@Column(name = "order_ID",insertable=false, nullable=false,  updatable=false)
public int getOrderId() {
    return this.orderId;
}

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

public boolean equals(Object other) {
    if ((this == other))
        return true;
    if ((other == null))
        return false;
    if (!(other instanceof OrderId))
        return false;
    OrderId castOther = (OrderId) other;

    return (this.getpartnerId() == castOther.getpartnerId())
            && (this.getemployeeId() == castOther.getemployeeId())
            && (this.getOrderId() == castOther.getOrderId());
}

public int hashCode() {
    int result = 17;

    result = 37 * result + this.getpartnerId();
    result = 37 * result + this.getemployeeId();
    result = 37 * result + this.getOrderId();
    return result;
}

}

Answer 1

我一直将鼠标悬停在万维网站点上的所有可能链接上，试图找到为什么不能将@GeneratedValue与@EmbeddedId或@IdClass（即复合PK）一起使用的原因。原因是您不能。这里提供的解释可能会帮助您感觉更好：
JAVA.NET/GLASSFISH

复合PK基于分配而不是基于生成。因此，任何@GeneratedValue东西都不应该与它们一起使用。我的项目也遇到了问题，我认为没有别的办法，除了：

如果您知道@GeneratedValue
ID在域（例如，数据库）的上下文中始终是唯一的，则无需使用复合PK并进行一些内部检查以确定记录的唯一性（即持久性对象集合） 。