RE: auto-update, auto-delete set dynamically?
Or you can map multiple beans to same table with different behavior. -Mensaje original- De: Mahler Thomas [mailto:[EMAIL PROTECTED]] Enviado el: jueves, 20 de febrero de 2003 17:23 Para: 'OJB Users List' Asunto: RE: auto-update, auto-delete set dynamically? Sure, we have a MOP inside (http://db.apache.org/ojb/links.html#design)! use http://db.apache.org/ojb/api/org/apache/ojb/broker/PersistenceBroker.html#ge tClassDescriptor(java.lang.Class) to obtain a classes descriptor. use http://db.apache.org/ojb/api/org/apache/ojb/broker/metadata/ClassDescriptor. html#getObjectReferenceDescriptorByName(java.lang.String) or similar to navigate to the reference or collection descriptor in question. use http://db.apache.org/ojb/api/org/apache/ojb/broker/metadata/ObjectReferenceD escriptor.html#setCascadeStore(boolean) to define update behaviour and http://db.apache.org/ojb/api/org/apache/ojb/broker/metadata/ObjectReferenceD escriptor.html#setCascadeDelete(boolean) do define delete behaviour. cheers, Thomas -Original Message- From: Robert S. Sfeir [mailto:[EMAIL PROTECTED]] Sent: Thursday, February 20, 2003 5:15 PM To: oJB List Subject: auto-update, auto-delete set dynamically? I was wondering if there was a method by which I could set auto-update, retrieve and delete from within my java code. I don't want to put it in the xml because sometimes when I select say a Home, I only want to have the home info, but I don't want to cascade my search. Sometimes when I delete an object there are instances where it's OK to cascade delete, others when it's not. Same goes with update. Thanks R -- Robert S. Sfeir Senior Java Engineer National Institutes of Health Center for Information Technology Department of Enterprise Custom Applications [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]
Re: auto-update, auto-delete set dynamically?
Thomas, I get this: PersistenceBroker broker = null; broker = PersistenceBrokerFactory.defaultPersistenceBroker(); ClassDescriptor cd = broker.getClassDescriptor( HomeBO.class ); ObjectReferenceDescriptor ord = cd.getObjectReferenceDescriptorByName(???);//??? because there is no explanation in the API as to WHICH name we need to use. ord.setCascadeRetrieve(false); The question is that if I'm using ODMG and I open my DB with: ... db = odmg.newDatabase(); db.open( DBC , Database.OPEN_READ_WRITE ); ... will the PersistenceBrokerFactory.defaultPersistenceBroker(); return anything at all? Second where I have the ??? the API has no documentation on what String value it's looking for (name has not description), but from the description of the class I'm guessing that it wants to know WHICH reference of the foreign-key who's attribute I want to assign to ord and then set its Cascade type to false... Is that correct??? I obviously haven't tested this yet so... If my assumptions above are all correct, then my feature request for future version is to have a method which can apply Cascade types across the board for the whole ClassDescriptor and its related classes. I think the way you have above is fine for now, but can be quite cumbersome on tables with a lot of inverse foreign keys. (that's assuming I understood where you were sending me) The reason I want to do this is, by the way, is because based on the user role in the application, I want to have the select update and delete behave different ways. For example if the user's role is DBA, then I want everything on and allow the DBA to cascade a delete if they want to, but if it's Joe User, then I don't even want to give them that option and have the default set to no in the repository files. R - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: auto-update, auto-delete set dynamically?
Hi again Robert, Robert S. Sfeir wrote: Thomas, I get this: PersistenceBroker broker = null; broker = PersistenceBrokerFactory.defaultPersistenceBroker(); ClassDescriptor cd = broker.getClassDescriptor( HomeBO.class ); ObjectReferenceDescriptor ord = cd.getObjectReferenceDescriptorByName(???);//??? because there is no explanation in the API as to WHICH name we need to use. the name of the reference attribute. corresponding to the name in the repository.xml If there is a reference attribute productGroup in your class, there will the following reference-descriptor: reference-descriptor name=productGroup class-ref=org.apache.ojb.broker.ProductGroup documentationthis is the reference to an articles productgroup/documentation foreignkey field-ref=productGroupId/ attribute attribute-name=color attribute-value=red / attribute attribute-name=size attribute-value=tiny / /reference-descriptor to obtain it use: cd.getObjectReferenceDescriptorByName(productGroup); ord.setCascadeRetrieve(false); The question is that if I'm using ODMG and I open my DB with: ... db = odmg.newDatabase(); db.open( DBC , Database.OPEN_READ_WRITE ); ... will the PersistenceBrokerFactory.defaultPersistenceBroker(); return anything at all? It will! PersistenceBrokerFactory.defaultPersistenceBroker() returns the broker with all the mapping definitions. Second where I have the ??? the API has no documentation on what String value it's looking for (name has not description), but from the description of the class I'm guessing that it wants to know WHICH reference of the foreign-key who's attribute I want to assign to ord and then set its Cascade type to false... Is that correct??? explained above I obviously haven't tested this yet so... If my assumptions above are all correct, then my feature request for future version is to have a method which can apply Cascade types across the board for the whole ClassDescriptor and its related classes. I think the way you have above is fine for now, but can be quite cumbersome on tables with a lot of inverse foreign keys. (that's assuming I understood where you were sending me) The PersistenceBroker API is meant to be a micro-kernel API. One of the base design guidelines is to not expose methods that can be assembled by several calls to simpler methods. Your feature request conflicts with this guideline. The reason I want to do this is, by the way, is because based on the user role in the application, I want to have the select update and delete behave different ways. For example if the user's role is DBA, then I want everything on and allow the DBA to cascade a delete if they want to, but if it's Joe User, then I don't even want to give them that option and have the default set to no in the repository files. The most natural thing would be to encapsulate the different cascade policies in different role classes. cheers, Thomas R - 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]
