Yes, I know I can use Select method to make a projection what I want, I ask about something more simple.
Thank you. On Wed, Mar 15, 2017 at 12:34 PM, Ricardo Peres <[email protected]> wrote: > Sorry, "You can". > > RP > > > On Wednesday, March 15, 2017 at 3:34:41 PM UTC, Ricardo Peres wrote: >> >> Use can, obviously, use projections and only fetch the properties you are >> interested in. Something like; >> >> var products = Session.Query<Product>().Select(p => new { >> p.Id, CategoryName = p.Category.Name <http://p.category.name/> >> }).ToList(); >> >> >> >> On Wednesday, March 15, 2017 at 12:35:16 PM UTC, Felipe Oriani wrote: >>> >>> Hey guys, I am looking at the problem for "select n+1" queries. It scare >>> us when I a session with more than 10 queries more than 100 in some cases >>> haha). Some refactoring to do. >>> >>> Sometimes I just need a string property to fill a column on the grid and >>> using `Fetch` extension method NHibernate fill the entire entity on the >>> relation.* Is there any way to tell to NHibernate fill up just a column >>> I need, without using the `Select` (from Linq) or `SelectLitst` (from >>> QueryOver)?* Something like this: >>> >>> var products = Session.Query<Product>().FetchProperty(p => >>> p.Category.Name).ToList(); >>> >>> @Nestor, these cases are not huge tables. it will not pass more than >>> 1000 records and some filters applied. >>> >>> Thank you Guys >>> >>> >>> On Wed, Mar 15, 2017 at 5:15 AM, Nestor Andres Rodriguez < >>> [email protected]> wrote: >>> >>>> Hi Felipe, >>>> >>>> Joins may be expensive. But what is really important prior to any >>>> optimization is to know how the data in this query behaves (reads, writes), >>>> how often this query will be executed, how important is this query for the >>>> business and customers, would it be a problem if it takes a few minutes , >>>> how up-to-date should be the information, seconds, minutes, hours. >>>> >>>> If this query needs for example to be executed in few milliseconds, and >>>> you have million of records on each of the 6 tables then probably you >>>> would like to avoid calculating the joins every time, so you may create a >>>> denormalised table which is updated regularly using some triggering >>>> mechanism, the downside is that you have to maintain yet another table and >>>> a trigger mechanism. >>>> >>>> At the end everything has a cost, and you need to identify if it worth >>>> it. If nobody complains and you do not see a good reason to optimize it, >>>> just do not care about that. >>>> >>>> Cheers, >>>> Nestor >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "nhusers" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/nhusers. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> >>> >>> -- >>> ______________________________________ >>> Felipe B Oriani >>> [email protected] >>> >> -- > You received this message because you are subscribed to the Google Groups > "nhusers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/nhusers. > For more options, visit https://groups.google.com/d/optout. > -- ______________________________________ Felipe B Oriani [email protected] -- You received this message because you are subscribed to the Google Groups "nhusers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/nhusers. For more options, visit https://groups.google.com/d/optout.
