If by Cartesian product you mean the join, then yes, this is how NHibernate do it.
Is there a way to change that? Not in NHibenate stuff. I do it (actually been experimenting this for a few days) by making the collection property settable, having two future queries (calling .ToFututre() on LINQ query or Future() on QueryOVer query) one for parent and another for child, then mapping the child entities to parent manually in a loop. If you are worried about multiple fetch paths, then you should do one query per fetch path, this will make a cartisian product for the parent entity and child path in the query only. which is better than getting cartestian product of all paths at the same time. You'll not need to map the child paths from different queries to the parent as, since parent is already returned in each queries, and NH keeps only one instance of each object, the parent from any of the queries will already have all child collections populated from different queries loaded into it. If you try to load the children only without the parent though, it will not map them to the parent coming from other queries then. Because it only does that when the return of the query requires creating new instance of the parent (or reusing existing if already there from another query). *Mohamed Meligy *Readify | Senior Developer M:+61 451 835006 | W: readify.net [image: Description: Description: Description: Description: rss_16]<http://gurustop.net> [image: Description: Description: Description: Description: cid:[email protected]] <http://www.linkedin.com/in/meligy> [image: Description: Description: Description: Description: cid:[email protected]] <http://twitter.com/meligy> <http://www.greatplacetowork.com.au/best/best-companies-australia.php><http://www.readify.net/AboutUs/NewsItem.aspx?id=10> On Mon, May 30, 2011 at 1:35 AM, Ricardo Peres <[email protected]> wrote: > Can you sent your mappings? Using a set should have done it, it is a > known issue. > > > On May 29, 7:37 am, Michael Teper <[email protected]> wrote: > > I have tried with both a set and a bag, no difference. How do you > > apply a transformer to a LINQ query? > > > > -Michael > > > > On May 27, 2:11 am, Ricardo Peres <[email protected]> wrote: > > > > > > > > > > > > > > > > > I think that's because you are using a bag. Try using a set instead, > > > it is a little change. > > > Otherwise, you will have to use the DistinctRootTransformer. > > > > > RP > > > > > On May 27, 9:22 am, Michael Teper <[email protected]> wrote: > > > > > > Except that I don't. I end up with *four* operations, *each* with > four > > > > steps. > > > > > > -Michael > > > > > > On May 26, 7:39 pm, Darren Kopp <[email protected]> wrote: > > > > > > > That is working correctly. Since you want to load all of the child > items, > > > > > you are getting all the child items, and you also have the data for > the > > > > > parent entity. nhibernate will rehydrate it into the correct form > so that > > > > > you'll have 1 operation with 4 steps using 1 query.- Hide quoted > text - > > > > > - Show quoted text - > > -- > 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. > > -- 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.
