jpa实体复合键错误

Question

private String carrid;
private String connid;
private String bookid;


public String getcarrid()
{
    return this.carrid;
}

public void setcarrid(String carrid)
{
    this.carrid = carrid;
}

public String getconnid()
{
    return this.connid;
}

public void setconnid(String connid)
{
    this.connid = connid;
}

public String getbookid()
{
    return this.bookid;
}

public void setbookid(String bookid)
{
    this.bookid = bookid;
}

 public int hashCode() 
 {
    return (int) ( this.carrid.hashCode())
            +(int) ( this.connid.hashCode())
            +(int) ( this.bookid.hashCode());

 }

 public boolean equals(Object obj) 
 {
    if (obj == this) return true;
    if (!(obj instanceof Booking)) return false;
    BookingPK pk = (BookingPK) obj;
    return  pk.carrid.equals(this.carrid)
            && pk.connid.equals(this.connid)
            && pk.bookid.equals(this.bookid);
 }



@Entity
public class Booking 
{
@EmbeddedId
private BookingPK bookingPrimaryKey;
private String CANCELLED;


public BookingPK getbookingPrimaryKey()
{
    return this.bookingPrimaryKey;
}

public void setbookingPrimaryKey(BookingPK key)
{
    this.bookingPrimaryKey = key;
}

public String getCANCELLED()
{
    return this.CANCELLED;
}

public void setCANCELLED(String CANCELLED)
{
    this.CANCELLED = CANCELLED;
}
}



@Embeddable
public class FlightPK implements Serializable 
{
private static final long serialVersionUID = 1L;

private String carrid;
private String connid;


public String getcarrid()
{
    return this.carrid;
}

public void setcarrid(String carrid)
{
    this.carrid = carrid;
}

public String getconnid()
{
    return this.connid;
}

public void setconnid(String connid)
{
    this.connid = connid;
}

  public int hashCode() 
  {
    return (int) ( this.carrid.hashCode())
            +(int) ( this.connid.hashCode());
  }

  public boolean equals(Object obj) 
  {
    if (obj == this) return true;
    if (!(obj instanceof Flight)) return false;
    FlightPK pk = (FlightPK) obj;
    return  pk.carrid.equals(this.carrid)
            && pk.connid.equals(this.connid);
 }
}



@Entity
public class Flight 
{
@EmbeddedId
private FlightPK flightPrimaryKey; 

private Booking bookedFlight;


public Booking getbookedFlight()
{
    return this.bookedFlight;
}

public void setbookedFlight(Booking flight)
{
    this.bookedFlight = flight;
}

public FlightPK getflightPrimaryKey()
{
    return this.flightPrimaryKey;
}

public void setPRICE(FlightPK key)
{
    this.flightPrimaryKey = key;
}
}

异常[EclipseLink-48]（Eclipse Persistence Services-2.3.2.v20111125-r10461):org.Eclipse.Persistence.exceptions.Description异常描述：字段[flight.connid]存在多个可写映射。只有一个可以定义为可写，所有其他的都必须指定为只读。映射:org.eclipse.persistence.mappings.oneTooneMapping[bookedFlight]描述符:RelationalDescriptor(testik.flight-->[databaseTable(FLIGHT)])

异常[EclipseLink-48]（Eclipse Persistence Services-2.3.2.V20111125-R10461):org.Eclipse.Persistence.exceptions.Description异常描述：字段[flight.carrid]存在多个可写映射。只有一个可以定义为可写，所有其他的都必须指定为只读。映射:org.eclipse.persistence.mappings.oneTooneMapping[bookedFlight]描述符:RelationalDescriptor(testik.flight-->[databaseTable(FLIGHT)])

at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:517)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getDatabaseSession(EntityManagerFactoryDelegate.java:188)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getMetamodel(EntityManagerFactoryDelegate.java:591)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getMetamodel(EntityManagerFactoryImpl.java:506)
at org.odata4j.producer.jpa.JPAEdmGenerator.generateEdm(JPAEdmGenerator.java:95)
at org.odata4j.producer.jpa.JPAProducer.<init>(JPAProducer.java:91)
at com.mockservice.MockService.<init>(MockService.java:34)
at com.mockservice.MockService.main(MockService.java:51)

由:Exception[EclipseLink-0]（Eclipse Persistence Services-2.3.2.v20111125-r10461):org.Eclipse.Persistence.exceptions.IntegrityException引起

请告知哪里出了问题。我已经尝试了每一件事，但都没有成功。

你好，斯拉维克。

Answer 1

发生此错误是因为您有多个属性映射相同的列。你的模特看起来很困惑。如果连接和承运人是唯一的，那么为什么预订需要另一个ID？或者一个航班怎么能有一个单独的预订？

就我个人而言，我不建议使用EmbeddedId，而建议使用IdClass，并在您的关系中使用@id。您还可以在联接列上使用insertable/updateable=false，但您的模型似乎很奇怪。

看，