Hi Stephane - I have been fighting this issue as well and is also using the multicriteria.
Have you tried traversing your "Cities" collection after the load? Try iterating you Continents list, and for each Country in the continent, hit its Cities collection and see if it goes into the database. I have been unable to make it work when more than one level. I usually get all the data in, but it seems that the nested collections is not initialized properly. Whenever I hit a collection at a nested at level 2+, NHibernate goes into the database. If your setup is working correctly I would really be interested in knowing more. Regards, Thomas On 9 Okt., 11:33, Stephane Farges <[email protected]> wrote: > I have found the solution below : > > IMultiCriteria vMC = CurrentSession.CreateMultiCriteria(); > vMC.Add<Continent>("continent", > CurrentSession.CreateCriteria<Continent>().SetFetchMode("Countries", > FetchMode.Eager).SetResultTransformer > (Transformers.DistinctRootEntity)); > vMC.Add<Country>("country", > CurrentSession.CreateCriteria<Country>().SetFetchMode("Cities", > FetchMode.Eager)); > > It's not as fast as I hoped it would be, but I'm not sure it's > possible to do better than this. > > On 8 oct, 18:13, Stephane Farges <[email protected]> wrote: > > > > > Hi, > > > I have a problem with selecting a deep object graph without Select N+1 > > or cartesian product. > > The model contains the classes Continent, Country and City. Each > > Continent contains a list of Country, and each Country contains a list > > of City, with bidirectionnal associations(Country has a Continent > > property and City has a Country property). > > > I want to load a list of all the Continents, with all the countries > > and cities. I know it is a lot of objects(around 2500 in total), but I > > don't have any other choice, and it was previously done with ADO.NET > > with acceptable performance. > > > I started by doing it the wrong way and I got either the Select N+1 > > problem or the Cartesian product problem, and it was not fast enough. > > > So I tried to do the following : > > > IMultiCriteria vMC = CurrentSession.CreateMultiCriteria(); > > vMC.Add<City>("city", CurrentSession.CreateCriteria<City> > > ()); > > vMC.Add<Country>("country", > > CurrentSession.CreateCriteria<Pays>()); > > vMC.Add<Continent>("continent", > > CurrentSession.CreateCriteria<Continent>()); > > > which gives good performance, but doesn't work because the relations > > are not initialized. > > > I have read this : > > http://ayende.com/Blog/archive/2007/06/20/Efficently-loading-deep-obj... > > but I'm not sure it applies in my case > > > Any idea how I can do this ? > > > Thanks, > > Stephane Farges.- Skjul tekst i anførselstegn - > > - Vis tekst i anførselstegn - --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
