spring-data-jpa 如何从扩展类重写继承的@MappedSuperclass @Column可更新和可插入属性

ee7vknir 于 2022-11-10 发布在 Spring

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在下面的设置中，如何使继承的producerId字段从Book中变为updatable = false, insertable = false？

@MappedSuperclass
public class StockItem {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "producer_id")
    private Integer producerId;

}

@Entity
public class Producer {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "name")
    private Integer name;

}

@Entity
@Table(name = "stock_item")
public class Book extends StockItem {

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "producer_id")
    private Producer producer;

    // make inherited producerId field updatable = false, insertable = false here

}

我特别不想执行以下操作，因为我需要该属性保持可更新和可插入，以供其他继承者使用：

@MappedSuperclass
public class StockItem {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "producer_id", updatable = false, insertable = false)
    private Integer producerId;

}

UPDATE：另一个约束是扩展@MappedSuperclass的所有类都表示同一个表

spring-data-jpa

来源：https://stackoverflow.com/questions/74205602/how-to-override-from-extending-class-inherited-mappedsuperclass-column-updat

2条答案

按热度按时间

yrefmtwq1#

我发现的一个变通方法是在producer setter中设置producerId，但这不是一个理想的解决方案。

@Entity
public class Book extends StockItem {

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "producer_id",  insertable = false, updatable = false)
    private Producer producer;

    public void setProducer(Producer producer) {
        setProducerId(producer.getId());
        this.producer = producer;
    }

    /**
        Setting producerId here directly may cause inconsistency between producer and inherited producerId, therefore method is overridden to be unusable.
    */
    @Override
    public void setProducerId(Integer producerId) {
        throw new UnsupportedOperationException("Inherited field producer cannot be set from Book");
    }

    @Override
    public Integer getProducerId() {
        return producer != null ? producer.getId() : null;
    }

}

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a7qyws3x2#

根据Asoub的建议，我使用@AttributeOverride执行了以下操作，它工作得很好，因为它允许修改所有列属性：

@Entity
@Table(name = "stock_item")
@AttributeOverride(
        name = "producerId",
        column = @Column(name = "producer_id", insertable = false, updatable = false)
)
public class Book extends StockItem {

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "producer_id")
    private Producer producer;

}

赞(0）回复(0）举报 2022-11-10

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spring-data-jpa 如何从扩展类重写继承的@MappedSuperclass @Column可更新和可插入属性

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