I don't follow. may be I should back up. what are you doing now? is it the code your originally posted? if not please post the actual code. what is happening? what do you want/expect to happen? what do you mean by cache? 1st level cache. also known as the identity map. or are you referring to 2nd level cache? I assume the 1st level cache, since you don't have caching enabled in the mapping.
if the entity exists in the 1st level cache and you query the database, but the object already exists in the cache the cached object is returned, not the database object. have you run your application through nhprof? this will give you an excellent idea of what's going on. On Sep 30, 11:25 am, Yauhen <[email protected]> wrote: > Are there any way to do without additional hit on database? For > example to make evict by id? > Because first get seen to me redundant. I need only updated entity not > original. And method should be as > > session get (hit db) > session update > session evict (if you don't evict get pulls for 1st level cache) > > On Sep 30, 5:58 pm, Jason Meckley <[email protected]> wrote: > > > if the next call comes from the same session, then you need to evict > > the object. example: > > session open > > session get (hit db) > > session update > > session evict (if you don't evict get pulls for 1st level cache) > > session get (hit db) > > > if the the call comes from a completely different session then you > > don't need to do anything. > > session 1: open > > session 2: open > > session 2: get (hit db) > > session1: update > > session2: get (1st level cache) > > this is by design > > > if you are expecting this: > > session 1: open > > session 2: open > > session 2: get (hit db) > > session1: update > > session2: get (hit db) > > ... > > it won't, not without evicting anyway. that is by design. there are 3 > > options to handle that > > 1. pessimistic concurrency (lock the database row) > > 2. optimistic concurrency (versioning) > > 3. call evict on session 2 > > > typically #2 provides better performance. it requires you to handle > > the StaleObjectException. #1 can result in command timeouts, so you > > would need to handle them as well. #3 goes against how NH is designed > > to operate. it's possible, but not advisable. also you cannot > > guarantee evict is called before session 1 update. > > > On Sep 30, 10:32 am, Yauhen <[email protected]> wrote: > > > > I simply need invalidate cache. So next call not get value fro cache > > > but from real database. > > > > On Sep 30, 5:27 pm, Roger Kratz <[email protected]> wrote: > > > > > I'm not sure I understand but... > > > > > << [...] Session is the same betwwen calls. [...]>> > > > > << [...] query.ExecuteUpdate(); [...] >> > > > > > Are you expecting your call to ExecuteUpdate to update the state inside > > > > your ISession? I don't think that will work. > > > > > Session keeps a first level cache. The state of this cache won't be > > > > updated when calling ExecuteUpdate AFAIK - no entities are returned. > > > > > /Roger > > > > > -----Original Message----- > > > > From: [email protected] [mailto:[email protected]] On > > > > Behalf Of Yauhen > > > > Sent: den 30 september 2010 16:10 > > > > To: nhusers > > > > Subject: [nhusers] Re: NHibernate cache > > > > > so nobody has ideas? > > > > > On Sep 28, 12:50 pm, Yauhen <[email protected]> wrote: > > > > > I have found very strange effect when using nhibernate. > > > > > I am trying to do one clever update operation. Then read saved data > > > > > from database. > > > > > Operations are mostly based on sql queries. In database data are ok. > > > > > But by some strange reason nhibernate uses cached old data. > > > > > Operations are described like following: > > > > > <class name="Message" table="Messages" > > > > > > <id name="Id" type="Int32" column="Id"> > > > > > <generator class="identity"/> > > > > > </id> > > > > > <property name="Subject" column="Subject" > > > > > type="String"/> > > > > > <property name="CategoryId" column="CategoryId" > > > > > type="Int32"/> > > > > > > <sql-query name="Message.Delete"> > > > > > <synchronize table="Messages"/> > > > > > UPDATE Messages > > > > > SET CategoryId = ( /* long select to decide to which category to > > > > > move*/ > > > > > ) > > > > > WHERE Id = :messageId > > > > > </sql-query> > > > > > > <sql-query name="Message.GetDetails"> > > > > > <return alias="msg" class="Message"/> > > > > > SELECT {msg.*} > > > > > FROM Messages {msg} > > > > > WHERE msg.Id = :messageId > > > > > </sql-query> > > > > > > when calling delete/update query I use syntax like following > > > > > using (ITransaction trans = _session.BeginTransaction()) > > > > > { > > > > > IQuery query = > > > > > _session.GetNamedQuery("Message.Delete"); > > > > > query.SetParameter<IdT>(paramName, id); > > > > > query.ExecuteUpdate(); > > > > > trans.Commit(); > > > > > > _session.Flush(); > > > > > } > > > > > when calling read: > > > > > IQuery query = _session.GetNamedQuery("Message.GetDetails"); > > > > > query.SetInt32("messageId", messageId); > > > > > query.List<Message>(); > > > > > > Session is the same betwwen calls. Caching occurs somewhere inside > > > > > NHibernate.Loader > > > > > > obj = session.GetEntityUsingInterceptor(key); > > > > > -- > > > > You received this message because you are subscribed to the Google > > > > Groups "nhusers" group. > > > > To post to this group, send email to [email protected]. > > > > To unsubscribe from this group, send email to > > > > [email protected]. > > > > For more options, visit this group > > > > athttp://groups.google.com/group/nhusers?hl=en. -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en.
