> I think Frans can tell that was just a joke :-)
I chuckled :)
> And yes, it is similar to CreateFilter, with one BIG difference: a
reference
> to NHibernate is not needed, which means you can safely use it from the
> Domain/Model classes without injecting a reference to the repository.
>
> The envisioned scenario is an extension of what can be currently
> accomplished with lazy="extra".
> For example, if you have a Currency entity with an ExchangeRates
collection
> (which is updated daily, hourly, whatever), you can do something like:
>
> var averageJulyRate = currency.ExchangeRates.AsQueryable()
> .Where(r => r.Date >= new DateTime(2010,
7,
> 1) &&
> r.Date < new DateTime(2010, 8,
> 1)
> .Average(r => r.Rate);
instead of: (Didn't remember te method on ISession to get an
IQueryable<T>, so I used .Linq<T>)
var averageJulyRate = session.Linq<ExchangeRate>()
.Where(r=>r.Currency.Id == currency.Id)
.Where(r => r.Date >= new DateTime(2010, 7,
1) &&
r.Date < new DateTime(2010, 8,
1)
.Average(r => r.Rate);
?
> Now, I'm sure there are bugs with the implementation, mostly in the form
of
> unsupported scenarios and naïve assumptions, because I'm still learning NH
> internals...
> But I'm pretty sure the feature itself is not a bug, but something that's
> been actively requested.
The downside I see is that it makes a call to the DB where you might
not expect it. With Linq it's already a struggle for some people (actually
more than you'd expect) to determine just from the query where which code is
ran: in memory or in the DB. With your feature you can think it's an
in-memory thing, but you actually make a call to the db, which could be a
problem when you receive the entities over a wire in a distributed scenario.
Other than that, the feature could be handy :) (I haven't tried it
out btw)
FB
>
> Diego
>
>
>
> On Fri, Sep 3, 2010 at 00:13, Fabio Maulo <[email protected]> wrote:
>
>
> Take care with your words...
> The fact that I had some squabble with Frans does not mean that I
> don't respect him and does not mean that we have to review all patches
with
> High priority.
>
> NH-2319 is the LINQ version of our CreateFilter, the patch is
> interesting but it need to be analyzed with more details.
> So far any LINQ applied to a collection, retrieved by NH, is always
> safe as any LinqToObject.
> Your request seems a bug masquerade of feature and needs a cautions
> discussion
>
>
> On Thu, Sep 2, 2010 at 11:46 PM, Diego Mijelshon
> <[email protected]> wrote:
>
>
> Anyone?
>
> C'mon guys, at least some criticism from the wind team!
> If you don't look at the received patches, Frans Bouma wins!
> (just kidding)
>
> Diego
>
>
>
> On Wed, Sep 1, 2010 at 00:19, Diego Mijelshon
> <[email protected]> wrote:
>
>
> I've implemented something I've seen requested
several
> times in SO and the users list: the ability to query persistent
collections
> using LINQ (server side, without initializing the collection and without
> referencing NHibernate).
>
> Patch: http://216.121.112.228/browse/NH-2319
>
> <http://216.121.112.228/browse/NH-2319> This
> implementation should work for generic bag, set and list, with two
> limitations: the relationship must be one-to-many and bidirectional. This
> should still account for the majority of the collections out there.
> There are probably many other ways in which it can
be
> improved, but I think it will be a useful feature.
>
> I'd really appreciate if any of the committers takes
> some minutes to review it and, hopefully, include it. Ping me if you have
> any questions.
>
> Diego
>
>
>
>
>
>
> --
> Fabio Maulo
>
>
>
