I changed Assert.That(NHibernateUtil.IsInitialized(c.Customers)); to Assert.That(c.Customers.Count == 2);
and it still hits the db, here is the SQL // for root select country0_.Id as Id0_, country0_.Name as Name0_ from Country country0_ where (Name='Germany' ) // for collection select customer0_.Id as Id1_, customer0_.Name as Name1_, customer0_.CountryId as CountryId1_ from Customer customer0_ where ([EMAIL PROTECTED] )and(customer0_.Name='GermanyCustomer1' ); @p0 = '1' // for collection.count SELECT customers0_.CountryId as CountryId1_, customers0_.Id as Id1_, customers0_.Id as Id1_0_, customers0_.Name as Name1_0_, customers0_.CountryId as CountryId1_0_ FROM Customer customers0_ WHERE [EMAIL PROTECTED]; @p0 = '1' On Fri, Oct 3, 2008 at 6:54 PM, Ken Egozi <[EMAIL PROTECTED]> wrote: > try to simply access the c.Customers and check (via show-sql or DB > profiler) that the DB is not being hit, but the customers data is being > hooked from the session cache. > > > On Fri, Oct 3, 2008 at 6:40 PM, Andrew Melnichuk < > [EMAIL PROTECTED]> wrote: > >> Hi all. >> >> I have a complex object graph. There is a root entity which has a set of >> collections (some of them are pretty big), entities in collections have >> their own collections etc.. - a kind of tree. I need to fetch this tree with >> minimum performance hit for database. I have tried 2 options for now: >> 1st - load root entity, and then navigate through properties to load all >> child and grandchild collections, ofcourse set fetch="subselect" in mapping >> file before, to prevent select n+1 problem >> 2nd - use approach, described here >> http://blogs.hibernatingrhinos.com/nhibernate/archive/2008/04/06/eager-loading-aggregate-with-many-child-collections.aspx, >> where different collections load by different queries, but session is smart >> enough, to merge different result to object graph, initializing different >> collections. >> >> But i can't use 1st approach, because i can't define fetch plan on a >> global level (number of reasons), and i can't use 2nd approach, because it >> seems that it works fine for 1st level collection only, selecting deeper >> level collections will produce cartesian product, which will grow with level >> of query of collection. >> >> What i thought about, is would it be possible to use approach based on >> several queries, like 2nd approach i mentioned. The difference is i tried to >> start fetching not from the root entity level, but from the level i have to >> fetch next, after i already fetched with previous query. For example: >> >> [Test] >> public void Test1() >> { >> // load root entity >> Country c = _session >> .CreateQuery("from Country where Name = 'Germany'") >> .List<Country>()[0]; >> >> // trying to load 1st level child collection >> _sess >> .CreateQuery("from Customer cs where cs.Country = :c") >> .SetParameter("c", c) >> .List(); >> >> Assert.That(NHibernateUtil.IsInitialized(c.Customers)); // >> fails >> } >> >> I thought that session will initialize Country.Customers collection, but >> it is not. >> Ofcourse i could use eager join for this collection and others at the same >> level, but as i said this will causes cartesian product for deeper >> collections. >> I'm not sure that what i did is valid, maybe it is invalid by design, >> however it seems that session can initialize customers collection, since it >> "knows" to which country selected customers belongs. >> >> Just wanted to ask, how people solve same problems. >> >> -- >> Best regards, >> Andrew Melnichuk >> >> >> > > > -- > Ken Egozi. > http://www.kenegozi.com/blog > http://www.musicglue.com > http://www.castleproject.org > http://www.gotfriends.co.il > > > > -- Best regards, Andrew Melnichuk --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
