:-) Anyway, could this possibly be a bug in OJB? Thanks! Alessandro
> Da: Armin Waibel <[EMAIL PROTECTED]> > Data: Mon, 23 Feb 2004 12:21:32 +0100 > A: OJB Users List <[EMAIL PROTECTED]> > Oggetto: Re: Auto delete and anonymous fields > > Hi, > > Alessandro Villamaina wrote: > > > Armin, > > > > I don't understand why I have to declare DBAttribute's "name" field as a foreign > > key > beside "owner" in DBObject. > > > > oh, sorry for the confusion, I made a mistake. You are right, in > DBObject only one PK is defined, so in DBAttribute one FK field 'owner' > is needed. > > regards, > Armin > > > I would like to allow a single DBAttribute with a given name per object, so I think > DBAttribute's PK is <name, owner>. > > > > DBObject has no knowledge of the fact that DBAttribute has a "name" attribute. > > Besides, > while "owner" refers to DBObject's PK "name", what would a second > inverse foreign key point to? > > > > Alessandro > > > > > >>Da: Armin Waibel <[EMAIL PROTECTED]> > >>Data: Sat, 21 Feb 2004 11:24:11 +0100 > >>A: OJB Users List <[EMAIL PROTECTED]> > >>Oggetto: Re: Auto delete and anonymous fields > >> > >>Hi Alessandro, > >> > >>in db.DBAttribute you declare two PK fields, thus in > >>collection-descriptor of db.DBObject you have to declare both fields as > >>inverse-foreignkey to match correctly. > >> > >>I don't know if there is an additional side-effect when declaring > >>PK/reference fields (e.g. 'owner') anonymous. > >>As I said in previous mails, I don't recommend to use anonymous fields > >>beyond 1:1 references. > >> > >>regards, > >>Armin > >> > >> > >>Alessandro Villamaina wrote: > >> > >>>Hi all, > >>> > >>>I have a problem using the auto-delete optiion in conjunction with anonymous > >>>fields. > >>> > >>>The classes I have to be made persistent in the DB (I'm using PostgreSQL) are > >>>(pseudo code): > >>> > >>>class DBObject > >>> private String name > >>> private Collection attributes > >>> > >>>class DBAttribute > >>> private String name > >>> private String value > >>> > >>>I want to set things up in order to get the DBAttributes belonging to a DBObject > >>>deleted when the DBObject itself gets deleted. > >>> > >>>The repository_user.xml file looks like > >>> > >>><class-descriptor class="db.DBObject" table="DBOBJECT"> > >>> > >>> > >>> <field-descriptor > >>> name="name" > >>> column="NAME" > >>> jdbc-type="VARCHAR" > >>> primarykey="true" > >>> /> > >>> > >>> > >>> <collection-descriptor > >>> name="_attributes" > >>> auto-delete="true" > >>> auto-update="true" > >>> element-class-ref = "db.DBAttribute"> > >>> <inverse-foreignkey field-ref = "owner" /> > >>> </collection-descriptor> > >>> > >>> > >>></class-descriptor> > >>> > >>> > >>><class-descriptor > >>> class="db.DBAttribute" > >>> table="DBATTRIBUTE"> > >>> > >>> > >>> <field-descriptor > >>> name="name" > >>> column="NAME" > >>> primarykey="true" > >>> jdbc-type="VARCHAR" > >>> /> > >>> > >>> > >>> <field-descriptor > >>> name="value" > >>> column="VALUE" > >>> jdbc-type="VARCHAR" > >>> /> > >>> > >>> > >>> <field-descriptor > >>> name="owner" > >>> column="OWNER" > >>> jdbc-type="VARCHAR" > >>> primarykey="true" > >>> access="anonymous" > >>> /> > >>></class-descriptor> > >>> > >>>As you can see, the OWNER column in the DBATTRIBUTE table keeps the link between > >>>an object and its attributes. There is no such attribute in the DBAttribute > >>>class, so I decided to make it an "anonymous" field, letting OJB handle it for me. > >>> > >>>The primary key of a DBATTRIBUTE record is the couple <name, owner>, since I want > >>>to allow a single attribute name for each object. > >>> > >>>When I save the DBObjects, everything works fine, and DBAttributes are made > >>>persistent along with their DBObjects. Peering into the DB tables, I can check > >>>that, for each record, the OWNER column contains the right reference to the owner > >>>object, and that is OK. > >>> > >>>When I delete one of the DBObjects, its attributes are NOT deleted. > >>> > >>>I tried to set the log4j logging level to DEBUG, and it turned out that the > >>>DELETE sql statements where, for each of the DBATTRIBUTE to be deleted: > >>> > >>>DELETE FROM DBATTRIBUTE WHERE name="name1" AND owner = NULL > >>> > >>>Obviously nothing is deleted from DBATTRIBUTE, since no owner is null in the > >>>table. > >>>The funny thing is that such DELETE statements are generated ONLY for the > >>>attributes that should be deleted, not for all attributes. This means that OJB > >>>"knows" (looking at the owner field, I guess) which attributes belong to the > >>>DBOBJECT and have to be deleted, but fails in assigning the right value to owner > >>>in the DELETE statement. > >>> > >>>Does anyone know how to solve this? > >>>Is this a bug or am I doing something wrong? > >>> > >>>Thanks a lot! > >>> > >>>Alessandro > >>> > >>> > >>>--------------------------------------------------------------------- > >>>To unsubscribe, e-mail: [EMAIL PROTECTED] > >>>For additional commands, e-mail: [EMAIL PROTECTED] > >>> > >>> > >>> > >> > >>--------------------------------------------------------------------- > >>To unsubscribe, e-mail: [EMAIL PROTECTED] > >>For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
