Hi, Someone asked for this recently, and I'm afraid I was too busy to reply.
When you lock an object (for update), it is *before* you make any changes to it. How can OJB know when to "automatically" flush changes to the database ? It can't; you have to tell it to. The same applies to locking an object for create; you can lock an object for create, *then* set the values on the object - it is only at commit/flush time that we know what the complete changes are... Cheers, Charles -----Original Message----- From: Guido Beutler [mailto:[EMAIL PROTECTED] Sent: 16 September 2003 08:38 To: OJB Users List Subject: Re: query before commit problem Hi Armin, what do you think to make it configurable. For managed enviroment the default would be a write through (or call it auto flush). I can not access the cvs so I can not test your new Tx implementation. :-( best regards, Guido Armin Waibel wrote: >Hi Guido, > >tx.checkpoint() is not allowed in managed >environments, because it does commit the >'underlying' connection (commit the current tx). > >Allowed to use is ((TransactionExt) tx).flush() >(new introduced interface ExtTransaction is not part >of rc4 - use CVS) >this perform object operations on connection without >commit the connection/tx. > >regards, >Armin > >----- Original Message ----- >From: "Guido Beutler" <[EMAIL PROTECTED]> >To: "OJB Users List" <[EMAIL PROTECTED]> >Sent: Monday, September 15, 2003 1:13 PM >Subject: Re: query before commit problem > > > > >>Hi, >> >>how to do it in managed enviroment? >> >>transaction.checkpoint() >> >>throws a not supported exception. >> >>best regards, >> >>Guido >> >> >>Jair da Silva Ferreira Júnior wrote: >> >> >> >>>Hi, >>> Thank you Thomas and Charles for your fast answers. I think I'll >>> >>> >use > > >>>transaction.checkpoint() as Charles pointed. >>> By the way, don't you think this would be a nice feature to be >>> >>> >added to > > >>>a future OJB version? Say, when an object is persisted insinde a >>> >>> >transaction > > >>>it would be nice if any query runned inside that transaction could >>> >>> >"see" > > >>>that object. >>> >>>Sincerely, >>> Jair Jr >>> >>> >>>----- Original Message ----- >>>From: "Charles Anthony" <[EMAIL PROTECTED]> >>>To: "'OJB Users List'" <[EMAIL PROTECTED]> >>>Sent: Friday, September 12, 2003 1:52 PM >>>Subject: RE: query before commit problem >>> >>> >>> >>> >>> >>> >>>>Hi, >>>> >>>>As Thomas says, this is by design. However, you can force the >>>> >>>> >transaction > > >>>> >>>> >>>to >>> >>> >>> >>> >>>>flush all object changes to the database, without committing the >>>> >>>> >>>> >>>> >>>underlying >>> >>> >>> >>> >>>>database connection : >>>> >>>>In RC4, you can use Transaction.checkpoint() e.g. t.checkpoint(); >>>> >>>>After RC4 (i.e. in CVS), you should be able to cast the transaction >>>> >>>> >to > > >>>>TransactionExt and invoke TransactionExt.flush >>>> >>>>e.g. (TransactionExt) t).flush() >>>> >>>>HTH, >>>> >>>>Cheers, >>>> >>>>Charles. >>>> >>>> >>>> >>>> >>>> >>>>>-----Original Message----- >>>>>From: Thomas Mahler [mailto:[EMAIL PROTECTED] >>>>>Sent: 12 September 2003 17:48 >>>>>To: OJB Users List >>>>>Subject: Re: query before commit problem >>>>> >>>>> >>>>>Hi Jair, >>>>> >>>>>ODMG transaction write to the db only on tx.commit. >>>>>Thus q is not persistent in the database when you perform the >>>>>first query! >>>>> >>>>>All queries (also ODMG OQL!) are executed against the >>>>>database. So it's >>>>>obvious that loaded != q after your query. >>>>> >>>>>after commiting the transaction q is stored in the DB and the >>>>> >>>>> >second > > >>>>>query does find it. >>>>> >>>>>Works as designed. >>>>> >>>>>-Thomas >>>>> >>>>>Jair da Silva Ferreira Júnior wrote: >>>>> >>>>> >>>>> >>>>> >>>>>>Hi, >>>>>> I am using ojb1.0_rc4, ODMG api with OJB queries and >>>>>> >>>>>> >>>>>> >>>>>> >>>>>mysql4. The problem is that when I persist an object and run a >>>>>identity query looking for the persisted objet the query >>>>>returns null. This only happens when I persist the object and >>>>>execute the query in the same transaction. Is this behaviour >>>>>correct or is this a bug? >>>>> >>>>> >>>>> >>>>> >>>>>> I added some example code in the end of this email for >>>>>> >>>>>> >>>>>> >>>>>> >>>>>better understanding. >>>>> >>>>> >>>>> >>>>> >>>>>> Thanks for your help. >>>>>> >>>>>>Sincerely, >>>>>> Jair Jr >>>>>> >>>>>>Example code: >>>>>> >>>>>>void doSomething(){ >>>>>> Transaction t=implementation.newTransaction(); >>>>>> t.begin(); >>>>>> Question q=new Question(); >>>>>> t.lock(q,t.WRITE); >>>>>> q.setStatement("a statement"); >>>>>> q.setNumber(10); >>>>>> q.setSubject(Subject.PHYSICS); >>>>>> q.setCorrectAlternative(Alternative.A); >>>>>> >>>>>> Question example=new Question(); >>>>>> example.setId(q.getId()); >>>>>> QueryByIdentity query=new QueryByIdentity(example); >>>>>> Question loaded=(Question) >>>>>> >>>>>> >>>>>> >>>>>> >>>>>((HasBroker)t).getBroker().getObjectByQuery(query); >>>>> >>>>> >>>>> >>>>> >>>>>> file://loaded==null !!! why? Shouldn't it be: loaded==q? >>>>>> t.commit(); >>>>>> >>>>>> t=implementation.newTransaction(); >>>>>> t.begin(); >>>>>> query=new QueryByIdentity(example); >>>>>> loaded=(Question) >>>>>> >>>>>> >>>>>> >>>>>> >>>>>((HasBroker)t).getBroker().getObjectByQuery(query); >>>>> >>>>> >>>>> >>>>> >>>>>> file://loaded!=null now! loaded==q! >>>>>> t.commit(); >>>>>>} >>>>>> >>>>>> >>>>>> >>>>>> >>>>--------------------------------------------------------------------- >>>> >>>> >>>>>To unsubscribe, e-mail: [EMAIL PROTECTED] >>>>>For additional commands, e-mail: [EMAIL PROTECTED] >>>>> >>>>> >>>>> >>>>> >>>>> >>>>This email and any attachments are strictly confidential and are >>>> >>>> >intended > > >>>>solely for the addressee. If you are not the intended recipient you >>>> >>>> >must > > >>>>not disclose, forward, copy or take any action in reliance on this >>>> >>>> >message > > >>>>or its attachments. If you have received this email in error please >>>> >>>> >notify > > >>>>the sender as soon as possible and delete it from your computer >>>> >>>> >systems. > > >>>>Any views or opinions presented are solely those of the author and >>>> >>>> >do not > > >>>>necessarily reflect those of HPD Software Limited or its affiliates. >>>> >>>>At present the integrity of email across the internet cannot be >>>> >>>> >>>> >>>> >>>guaranteed >>> >>> >>> >>> >>>>and messages sent via this medium are potentially at risk. All >>>> >>>> >liability > > >>>>is excluded to the extent permitted by law for any claims arising as >>>> >>>> >a re- > > >>>>sult of the use of this medium to transmit information by or to >>>>HPD Software Limited or its affiliates. >>>> >>>> >>>> >>>> >>>> >>>--------------------------------------------------------------------- >>> >>> >>>>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] This email and any attachments are strictly confidential and are intended solely for the addressee. If you are not the intended recipient you must not disclose, forward, copy or take any action in reliance on this message or its attachments. If you have received this email in error please notify the sender as soon as possible and delete it from your computer systems. Any views or opinions presented are solely those of the author and do not necessarily reflect those of HPD Software Limited or its affiliates. At present the integrity of email across the internet cannot be guaranteed and messages sent via this medium are potentially at risk. All liability is excluded to the extent permitted by law for any claims arising as a re- sult of the use of this medium to transmit information by or to HPD Software Limited or its affiliates. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
