That doesn't seem to make sense. ObjectTwo doesn't only have to be associated with ObjectOne types, but many other types as well. It's a common attribute of types in this system.
For example, suppose ObjectTwo is color while ObjectOne is a car. There is a many-to-many relationship between the two, even though it only makes sense to associate them one way. Perhaps you also want to add fruits to the database and associate them in a many-to-many fashion with colors. Would the color type now have to support a reverse relationship between the cars AND the fruits? -Ron -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Monday, May 02, 2005 8:22 AM To: [email protected] Subject: Re: RE: [castor-dev] many-to-many mapping.. Ronald, I think it's required to map both sides of the relation. Try doing it. Regards, Emir ----- Original Message ----- From: Ronald Rudy <[EMAIL PROTECTED]> Date: Monday, May 2, 2005 2:23 pm Subject: RE: [castor-dev] many-to-many mapping.. > Here is my mapping: > > <class name="com.xyz.ObjectOne" identity="oneId" > key-generator="SEQUENCE"> > <description>"First of Many-to-Many Object"</description> > <map-to table="object_one"/> > <cache-type type="none"/> > <field name="oneId" type="integer"> > <sql name="object_one_id" type="integer"/> > </field> > > ... > > <field name="objectTwo" type="com.xyz.ObjectTwo" > collection="arraylist"> > <sql name="object_two_id" many-table="objectone_objecttwo_map" > many-key="object_one_id" key-generator="SEQUENCE" /> > </field> > </class> > > > <class name="com.xyz.ObjectTwo" identity="twoId" > key-generator="SEQUENCE"> > <description>"Second of Many-to-Many Object"</description> > <map-to table="object_two"/> > <cache-type type="none"/> > <field name="twoId" type="integer"> > <sql name="object_two_id" type="integer"/> > </field> > > ... > > </class> > > > I didn't include a reverse mapping from the ObjectTwo -> ObjectOne > because I > don't have/need a property on the com.xyz.ObjectTwo class to get > back to > ObjectOne. > > The mapping table objectone_objecttwo_map has three relevant fields: > > primary key of the mapping table itself > foreign key of 'object_one' record this is associated with > foreign key of 'object_two' record this is associated with > > -Ron > > -----Original Message----- > From: Werner Guttmann [EMAIL PROTECTED] > Sent: Monday, May 02, 2005 8:12 AM > To: [email protected] > Subject: AW: [castor-dev] many-to-many mapping.. > > > Ronald, > > there's no need to define a mapping object, as your many-to-may > relationwill be handled automatically by Castor. And this should > by definition > include the handling of the keys in the mapping table. It looks > like you > have got the mapping slightly wrong, so can you please post the > relevantmapping section, the DDL used to create the tables in > question and some > information about the classes engaging in such mapping ? > > Werner > > -----Urspr�ngliche Nachricht----- > Von: Ronald Rudy [EMAIL PROTECTED] > Gesendet: Montag, 02. Mai 2005 14:08 > An: [email protected] > Betreff: [castor-dev] many-to-many mapping.. > > > I have configured Castor to support a many-to-many relationship > between two > types of objects, but I'm getting an error. This is because the > mappingtable itself (in Oracle) contains a primary key of its own, > and this is not > automatically assigned by Castor. So when a new relationship is > created,this primary key is null and the database throws an error. > > I don't have control over the database schema - is there any way to > configure Castor to recognize that the configured many-table has a > primarykey and the key can be created using the sequence key > generator? (the > sequence key generator works fine for everything else) Or am I > going to be > forced to create a "map" object that handles the relationship > 'manually'? > -Ron > > >
