Question

我有两个实体BillingAddress和ShippingAddress映射到具有鉴别器TYPE列的TABLE ADDRESS。

@Entity
@Table(name = "address")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "TYPE",discriminatorType = DiscriminatorType.INTEGER)
@DiscriminatorValue(value = "1")
@NamedQueries({
    @NamedQuery(name = "Shippingaddress.findAll", query = "SELECT s FROM Shippingaddress s")})
public class Shippingaddress  implements Serializable{}

@Entity
@Table(name = "address")
@DiscriminatorValue(value = "2")
@NamedQueries({
    @NamedQuery(name = "Billingaddress.findAll", query = "SELECT b FROM Billingaddress b")})
public class Billingaddress extends Shippingaddress implements Serializable {}

我能够在具有不同TYPE值的DB中成功保存/更新两种地址类型。

我遇到的问题是当我按如下方式查询ADDRESS表时：

Session session=getCurrentSession();
        Query query=session.createQuery("from Billingaddress where userId.userId=:userId");
        query.setLong("userId", userId);
        billingaddress=(Billingaddress)query.uniqueResult();

这样可以正常工作，但查询ShippingAddress会抛出NonUniqueResult异常，即我在结果中同时获得Shippingaddress和Billingaddress。请让我知道，我应该做些什么。

Session session=getCurrentSession();
        Query query=session.createQuery("from Shippingaddress where userId.userId=:userId");
        query.setLong("userId", userId);
        shippingaddress=(Shippingaddress)query.uniqueResult();

Answer 1

另一个解决方案是创建一个抽象类Address并使用＆＃34; insertable = false，updatable = false＆＃34;

映射父类中的列。

然后您可以在查询中添加类型：

@Entity
@Table(name = "address")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "TYPE",discriminatorType = DiscriminatorType.INTEGER)
@NamedQueries({
@NamedQuery(name = "Address.findAll", query = "SELECT s FROM Address s where type = :type")})
public class Address implements Serializable {
    @Column(name="TYPE", insertable=false, updatable=false)
    private Integer type;
}

@Entity
@DiscriminatorValue(value = "1")
@NamedQueries({
@NamedQuery(name = "Shippingaddress.findAll", query = "SELECT s FROM Shippingaddress s")})
public class Shippingaddress  implements Serializable{}

@Entity
@DiscriminatorValue(value = "2")
@NamedQueries({
@NamedQuery(name = "Billingaddress.findAll", query = "SELECT b FROM Billingaddress b")})
public class Billingaddress extends Shippingaddress implements Serializable {}

然后你可以写一个＆＃34;来自地址，其中type = 1＆＃34;与来自Shippingaddress＆＃34;的＃34;相同和＃34;来自地址＆＃34;将检索所有行

Answer 2

DiscriminatorColumn＆amp; DiscriminatorValue不能在同一个类上工作......我建议你定义一个像这样的抽象类......

为层次结构

尝试此配置

<强> ShippingaddressAbstract.java

@Table(name = "address")
@Inheritance
@DiscriminatorColumn(name = "TYPE",discriminatorType = DiscriminatorType.INTEGER)
public abstract class ShippingaddressAbstract implements java.io.Serializable {

}

<强> Shippingaddress.java

@Entity
@DiscriminatorValue(value = "1")
public class Shippingaddress extends ShippingaddressAbstract {

}

<强> Billingaddress.java

@Entity
@DiscriminatorValue(value = "2")
public class Billingaddress  extends ShippingaddressAbstract {

}

Hibernate单表继承

2 个答案: