Hibernate version:
1.2

I am searching for a way of how to select specific properties using ICriteria, and not all objects.

As an example, the expected end result is array of object[] , containing the required properties.
The code i expect might look like this:



What i actually found in NHibernate 1.2 is
* a SQL based query (http://www.hibernate.org/hib_docs/nhibe ... rysql.html).



However, this sql query returns me a collection of cats, and not the properties i need.

* There are many more query types detailed in nhibernate chapter 9

but i could not find what i need, i.e. ICriteria fetching with ability to select distinct properties.


Is there a way to achieve this?



To summarize, what I want is ability to construct queries using ICriteria API, and to bypass hydration - instead of real objects i want to get a raw sql result table

Update
I found that projections might help. Reading them.. 12.7. Projections, aggregation and grouping

You can use hql query instead of native query

select cat.Surname from Cat as cat where cat.Name = "kitty"

you will get a collection of strings

That's feasible, but not what i need.

First - we have a structure which defines filters and visible columns for a grid, so constructing HQL would be very furstrating. strings is not what I am comfortable with

Second - i could not manage to write a HQL query with Limit support.



But for my problem i have found a solution, possibly.
Take a look at this:
ProjectionQuery on Ayende

It seems i found solution.

As i said, it was about using projections.

The code which does what i want:

"To summarize, what I want is ability to construct queries using ICriteria API, and to bypass hydration - instead of real objects i want to get a raw sql result table"

Yeah for that you do want projection. But I'm wondering why you'd bother with NHibernate then? If you really, truly want to avoid all objects and want a table result-set, why not just use ADO.NET (or other database) directly?

I don't want to be cocky, but if you're going to ask how can I not use objects within Object software, then I suppose somebody has to ask this ;-)

You don't have to justify anything, but I'm interested in your reasons. Is there a known, worthwhile performance benefit for what you're doing? Do you know exactly what the benefit is (ie you've measured it).

Your question hit the right spot.

I wrote about it my blog, here you can read it:
http://griuvesiai.blogspot.com/2007/09/performance-upgrade-month.html
http://griuvesiai.blogspot.com/2007/09/performance-upgrade-month-2.html