I have the following abstract class with property sysProp on it.
@Table(name="DDB_System")
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
@Entity(name="System")
public abstract class System
.....................................
@Column(name="sysProp1",length=1024)
@Basic
private String sysProp1;
System also has multiple subclasses, each with properties of their own:
@Table(name="ComputerSystem") ** This has multiple concrete
subTypes**
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
@DiscriminatorValue(value="ComputerSystem")
@Entity(name="ComputerSystem")
public class ComputerSystem extends System
.....................................
@Column(name="csProp1",length=1024)
@Basic
private String csProp1;
and
@DiscriminatorValue(value="OperatingSystem")
@Entity(name="OperatingSystem")
public class OperatingSystem extends System
.....................................
@Column(name="osProp1",length=1024)
@Basic
private String osProp1;
I have another entity that is directly related to the "System" abstract
class.
@Table(name="A")
@Entity(name="A")
public class A
........................
@ManyToOne
@PrimaryKeyJoinColumn(name="SOURCEID",referencedColumnName="OID")
private System Source;
When I try to query over this relationship and include a property from the
abstract class, it fails:
"select m from A m where m.Source.sysProp1 = 'z'"
Caused by: <openjpa-1.2.0-r422266:683325 fatal user error>
org.apache.openjpa.persistence.ArgumentException: Cannot join across
"A.Source". The related type has unjoined subclasses.
at org.apache.openjpa.jdbc.meta.strats.RelationStrategies.unjoinable(
RelationStrategies.java:53)
If I change the query to include a property from one of the subTypes, it
fails because it doesn't know about that property:
"select m from A m where m.Source.osProp1 = 'z'"
Caused by: <openjpa-1.2.0-r422266:683325 nonfatal user error>
org.apache.openjpa.persistence.ArgumentException: An error occurred while
parsing the query filter "select m from A m where m.Source.osProp1 = 'z'".
Error message: No field named "osProp1" in class "class System".
at
org.apache.openjpa.kernel.exps.AbstractExpressionBuilder.parseException(
AbstractExpressionBuilder.java:118)
An archived post
(http://mail-archives.apache.org/mod_mbox/openjpa-users/200711.mbox/%[email protected]%3e)
said to add the @Type annotation to relationship property. When I changed
it to the following, both queries worked as expected:
@ManyToOne
@PrimaryKeyJoinColumn(name="SOURCEID",referencedColumnName="OID")
@Type(OperatingSystem.class)
private System Source;
My problem is that this lets me set one concrete subType, but I have more
than one. Is there a way to set multiple. Any query going to the other
subType still won't work:
"select m from A m where m.Source.csProp1 = 'z'"
Thanks,
Jeff Awe
Email: [email protected]
Dept: ELH Phone: 507-253-1955 T/L: 553-1955
