http://knol.google.com/k/fabio-maulo/nhibernate-chapter-9/1nr4enxv3dpeq/12
> 9.4.3. Reattaching detached objects > > The Lock() method allows the application to reassociate an unmodified > object with a new session. > > //just reassociate: > sess.Lock(fritz, LockMode.None); > //do a version check, then reassociate: > sess.Lock(izi, LockMode.Read); > //do a version check, using SELECT ... FOR UPDATE, then reassociate: > sess.Lock(pk, LockMode.Upgrade); > > Also see http://nhforge.org/doc/nh/en/index.html for the original source. Also look for mentions of "pessimistic locking". Ted On Thu, Jun 4, 2009 at 1:03 AM, MattF <[email protected]> wrote: > > can you explain what the lock method does and why it works? > > i saw someone using it but i didn't really know what the consequences > are. > > thanks > > On Jun 4, 2:28 pm, Ted Gifford <[email protected]> wrote: > > The Lock method on NHibernate Session is similar to what you're asking. > > Don't think AR has that method, but you can always access the underlying > > session. > > > > Ted > > > > > > > > On Wed, Jun 3, 2009 at 10:37 PM, MattF <[email protected]> wrote: > > > > > if anyone knows an answer to this, i would still very much like to > > > hear it. > > > > > however i have just changed my web service to not return the AR Model > > > objects. > > > > > so my update method now does this (psedocode): > > > > > Update(ThingyData data) > > > { > > > Thingy thingy = GetThingyFromDB(data.Id); > > > UpdateThingyFromData(thingy, data); > > > UpdateThingyInDB(thingy); > > > } > > > > > which is probably the "right" way to do it anyway, so that my client > > > isn't tied to my DB Model > > > > > On Jun 3, 10:20 am, MattF <[email protected]> wrote: > > > > what would be nice is if i could put some thing into it so that > before > > > > it goes to update any object, if it doesn't have the current state of > > > > the object it goes and retrieves it from the DB in a way which would > > > > mean that my postupdate has the OldState. > > > > > > this way my actual web method could stay how it is (free of any of > > > > this logic) > > > > > > On Jun 3, 10:11 am, MattF <[email protected]> wrote: > > > > > > > This has probably been asked before, but i couldn't find a existing > > > > > post explaining it. > > > > > > > Currently we have a web service which is accessed by our client > > > > > application in order to talk to the database. > > > > > > > The asmx WebService has web methods similar to this (this is a > > > > > simplification): > > > > > NOTE: Thingy is an AR Model > > > > > > > [WebMethod] > > > > > public Thingy GetThingy(int id) > > > > > { > > > > > return ActiveRecordMediator<Thingy>.FindByPrimaryKey(id); > > > > > > > } > > > > > > > [WebMethod] > > > > > public Thingy UpdateThingy(Thingy thingy) > > > > > { > > > > > ActiveRecordMediator<Thingy>.Update(thingy); > > > > > return thingy; > > > > > > > } > > > > > > > there is also some other code in another part of the code which > > > > > basically creates a SessionScope for each web request. > > > > > > > Now, this code seemed to work at first (updated the DB > appropriately). > > > > > However then i added an IPreUpdateEventListener which is basically > > > > > used to log which properties on each object where changed. > > > > > > > The problem that i had is in the OnPostUpdate(PostUpdateEvent > > > > > postUpdateEvent) method of my EventListener > postUpdateEvent.OldState > > > > > is always null. > > > > > > > After some research and asking questions i have worked out that > this > > > > > is because when calling the Update web method, the 'thingy' that is > > > > > passed in is a detatched model (not attatched to the current > session) > > > > > so AR has no way of knowing the previous values of the Thingy > (which > > > > > makes sense). > > > > > > > however i need to find some way of updating the thingy in the > > > > > database, but still being able to know which properties where > changed > > > > > in that row of the database. > > > > > > > I understand that i may have to do a FindByPrimaryKey before i do > the > > > > > update so that AR can know the state of the object before the > update. > > > > > but i couldn't get it to work by just doing a find and then an > update > > > > > on the object passed in as the parameter. > > > > > > > p.s. i realize i could probably get it to work by doing a Find, > then > > > > > updating the returned object manually from the object passed in > (and > > > > > then saving the object returned from the find)... but i don't want > to > > > > > have to update the object manually, because this is going to have > to > > > > > be done for many-many different models, so i need a method that is > not > > > > > fragile and can be done pretty simply for any type > > > > > > > thanks in advance > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Castle Project Users" group. 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