composite foreign key as part of composite primary key

Kuni · **Joined:** Wed Jun 11, 2008 5:21 pm **Posts:** 2

Hello,

i'm trying to define a complex composite key szenario but i'm still getting errors.

situation:

1. table MASTERDATA ( xxx, yyy, zzz; pk (xxx,yyy) )

2. table USAGEDATA (aaa,bbb,xxx,yyy, tttt); pk(aaa,bbb,xxx,yyy))
with "virtual" foreignKey(xxx,yyy) references MASTERDATER.

the foreign key is "virtual" which means, that the key is not defined in the datebase. it's only present in the logical model. the fields USAGEDATA.xxx and USAGEDATA.yyy where primary and foreig key at once.

this is my attemt:

Code:

@Embeddable
public class MasterdataPk
{
 String xxx;
 String yyy;
}

@Entity
@Table(name="MASTERDATA")
public class Masterdata
{
  @Id MasterdataPk id;
  String zzz;
}


@Embeddable
public class UsageDataPk
{
 Masterdata masterdata;
 String aaa;
 String bbb;
}

@Entity
@Table(name="USAGEDATA")
public class UsageData
{
 @Id UsageDataPk id;
 String ttt;
}

hibernate generates:

Code:

select ... a.masterdata_xxx, a. masterdata_yyy from USAGEDATA a ...

but i'm expecting a join like

Code:

select ... b.xxx, b._yyy from USAGEDATA a, MASTERDATA b where a.xxx = b.xxx and a.yyy = b.yyyy ... 

i'm getting confused ;-)

thanks in advance

mmerder · **Posted:** Thu Jan 29, 2009 5:52 am

try to use @EmbeddedId instead of @Id, I am wondering why it works without.

Also you should define a toOne-Relationship:

Code:

@Embeddable
public class UsageDataPk
{
 @ManyToOne
 Masterdata masterdata;
 String aaa;
 String bbb;
} 