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  • Jpa/Hibernate ManyToOne 关联非主键列 延迟加载失效

    @ManyToOne配置延迟加载,如果是关联主键列,

        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = "billid", insertable = false,updatable = false, nullable = false)
        private Bill bill ;
    @Setter
    @Getter
    @Entity
    @DynamicUpdate
    @Table(name = "Bill")
    public class Bill implements Serializable {
    
        /**
         * 主键
         */
    
        @Id
        @Column(name = "ID")
        private String id;
    
       @Column(name = "SID")
        private String sid;
    }

    延迟加载是正常的。

    但如果关联的Address的是sid而不是id的话,就延时加载就有问题。如下代码:

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "billid", referencedColumnName = "sid", insertable = false,updatable = false, nullable = false)
    private Bill bill;

    这时的解决方案,需要了解PersistentAttributeInterceptable的机制。

    @DynamicUpdate
    @Entity
    @Setter
    @Getter
    @Table ( name ="BillDETAIL" )
    public class BillDetail implements PersistentAttributeInterceptable, Serializable {
        
    @ManyToOne(fetch
    = FetchType.LAZY) @JoinColumn(name = "billid", referencedColumnName = "sid", insertable = false,updatable = false, nullable = false) @LazyToOne(LazyToOneOption.NO_PROXY) private Bill bill; public Bill getBill() { if (interceptor!=null) { return (Bill)interceptor.readObject(this, "bill", bill); } return bill; } public void setBill(BillView bill) { if (interceptor!=null) { this.billView = (Bill) interceptor.writeObject(this,"owner", this.bill,bill); return ; } this.bill = bill; } @Transient private PersistentAttributeInterceptor interceptor; @Override public PersistentAttributeInterceptor $$_hibernate_getInterceptor() { return interceptor; } @Override public void $$_hibernate_setInterceptor(PersistentAttributeInterceptor interceptor) { this.interceptor = interceptor; } }

    参考:

    https://blog.csdn.net/johnf_nash/article/details/86557107     

    https://blog.csdn.net/windsigirl123/article/details/60957632

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  • 原文地址:https://www.cnblogs.com/hankuikui/p/11429214.html
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