Hi Florin, <snip> > > Regards, > Florin > > PS: I have another question: is it possible in OJB to map an > object field to > a calculated value. For example I have a birthday column in > PERSON table and > I want to have in the Person class a field age containing the > age of the > person( > age = currentDate - birthday, or something like this)
There are several ways to achieve this. 1. instance callbacks. you can implement a hook method that calculates the age attribute on loading the instance from the DB. (see http://db.apache.org/ojb/tutorial3.html#instance%20callbacks) 2. you could use a FieldConversion to to the Job (http://db.apache.org/ojb/jdbc-types.html#defining%20type-%20and%20value%20c onversions) 3. you could also use a nested Object approach (http://db.apache.org/ojb/tutorial3.html#nested%20objects) 4. you could use a RowReader (http://db.apache.org/ojb/tutorial3.html#using%20rowreaders) I depends a lot on the context which is the best solution. In general I consider 2) and 3) to be easier to use for this scenario. Thomas > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Tuesday, November 04, 2003 2:22 PM > To: [EMAIL PROTECTED] > Subject: RE: Loading an object > > > Hello, > > > -----Original Message----- > > From: Florin Pop [mailto:[EMAIL PROTECTED] > > > I tried: > > > > Criteria crit = new Criteria(); > > crit.addEqualTo("id", new Long(PERSON_ID)); > > Query query = new QueryByCriteria(Person.class, crit); > > Person person = (Person) broker.getObjectByQuery(query); > > > > but it works very slow, 6-8 times slower than in Hibernate: > > I do not believe that. > > [..] > > > Is there another way for doing this in OJB? > > try: > > Identity id = new Identity(Person.class, Person.class, > new Long[] {new Long(PERSON_ID)}); > PersistenceBroker.getObjectByIdentity(id); > > > Olli > > --------------------------------------------------------------------- > 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]
