Thanks Armin, your reply is very helpfull. so there is no direct solution we must call store two time , one for A another for B. in your opinion why is not possible to use the same philosophy of the invers-foreignekey wich is used in 1:n ????
an other question about performance this time : i don't know how can we do it in OJB ; when OJB prepare a statement (for read) by default he make SELECT * FROM ... so i think if we have a posibility to specify only fields that's we need instead of (*) we got a good result at performance level in reading. ??? how can i do this in OJB thx in advance. On 2/14/06, Armin Waibel <[EMAIL PROTECTED]> wrote: > > Hi, > > ABOU LINA wrote: > > Hi, > > > > i give you this sample example : > > > > in case A<---->B [1:n] : > > the mapping of this bidiractional navigation is guaranted by the > use of > > inverse-foreignkey : > > > > Mapping A classe : > > ---------------------------------------------------- > > > > <collection-descriptor > > name="allB" > > element-class-ref="B" > > > > > <inverse-foreignkey field-ref="aId"/> > > </collection-descriptor> > > > > > > Mapping B class : > > ------------------------------ > > <reference-descriptor > > name="a" > > class-ref="A" > > > > > <foreignkey field-ref="aId"/> > > > > </reference-descriptor> > > > > so in case of A<---->B [1:1] i need a bidirectional navigation !!!!! > > how to use ???? > > > > Do you mean how to map it? > Declare in both classes A and B a 1:1 reference-descriptor (both class > tables need a FK column). > > How to insert? > This depends strongly on the used auto-xxx settings. If > auto-update/delete is enabled (and PK values handled by OJB) you can do > e.g.: > > broker.beginTransaction(); > // first store both objects > broker.store(a, ObjectModification.INSERT); > // or let OJB detect the needed operation (more overhead) > //broker.store(a); > broker.store(b, ObjectModification.INSERT); > // now set references > a.setRelatedB(b); > b.setRelatedA(a); > // update both > broker.store(a, ObjectModification.UPDATE); > broker.commitTransaction(); > > or () > > // set references first > a.setRelatedB(b); > b.setRelatedA(a); > broker.beginTransaction(); > // store both objects > broker.store(a); > // update b to force OJB to set the FK > // back to a (was 'null' after first store call) > broker.store(b); > broker.commitTransaction(); > > or if auto-update 'link' is used > > broker.beginTransaction(); > // first store both objects > broker.store(a, ObjectModification.INSERT); > broker.store(b, ObjectModification.INSERT); > // now set references > a.setRelatedB(b); > b.setRelatedA(a); > // update both > broker.store(a, ObjectModification.UPDATE); > broker.store(b, ObjectModification.UPDATE); > broker.commitTransaction(); > ... > > regards, > Armin > > > > my config : > > 1. ojb 1.0.3 > > 2. i use the broker (PB-API) > > > > > > > > Thanks a lot .... > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > >
