So, there is no chance to OJB identify (by the complete class name) that the classes are not same for same PK id, and then use correct class-descriptor and instantiate correct class?
Jakob Braeuchi wrote:
hi edson,
this is imo a know fact. ojb requires to pk to be unique within a class hierarchy. let's assume you have a class D referencing 1:1 an A identified by
id =1. if this id is not unique in the class hierarchy, then ojb does not know if it's an A, B or C. imo there's no other way than to define th pk unique.
jakob
Edson Carlos Ericksson Richter wrote:
Of course, I'll try (all package test).
public class A { public int id; public String description; }
public class B extends A { public double value; }
public class C extends A { public Date value; }
<class-descriptor class="test.A"> <extent-class class-ref="test.B" /> <extent-class class-ref="test.C" /> </class-descriptor>
<class-descriptor class="test.B" table="tableB"> <field-descriptor name="id" column="id" jdbc-type="INTEGER" primary-key="true"/> <field-descriptor name="description" column="description" jdbc-type="VARCHAR"/> <field-descriptor name="value" column="value" jdbc-type="DOUBLE"/> </class-descriptor>
<class-descriptor
class="test.C" table="tableC">
<field-descriptor
name="id"
column="id"
jdbc-type="INTEGER"
primary-key="true"/>
<field-descriptor
name="description"
column="description"
jdbc-type="VARCHAR"/>
<field-descriptor
name="value"
column="value"
conversion="org.apache.ojb.broker.accesslayer.conversions.JavaDate2SqlTimestampFieldConversion"
jdbc-type="TIMESTAMP"/> </class-descriptor>
Now fill with data:
insert into tableB (id, description, value) values (1, 'testB1', 123.45)
insert into tableB (id, description, value) values (2, 'testB2', 234.56)
insert into tableC (id, description, value) values (1, 'testC1', '2004-04-01 00:00:00.000')
insert into tableC (id, description, value) values (2, 'testC2', '2004-04-01 00:00:00.000')
Then try to read all with query by criteria, or something, over test.A class. You will get a collection of 4 objects B or 4 objects C (depending what the databased returned first!!!).
The problem here as far as I can see is because either B and C has exactly same PK definition and same values for PKs. As I related, if I add some kind of field to diferentiate the PK, result is right.
Best regards,
Edson Richter
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