Hi,

I'm having problems with aggregate queries. I'm using NHibernate 1.0.2.0

I have a HQL query which performs a SUM() of a multiplication; like this:



Now, in NHibernate, this doesn't work. The query is not correctly translated (at least not in the nhibernate version i'm using)

Then, I want to try to solve this using native SQL, via the CreateSQLQuery method.
However, this method takes 3 arguments: the SQL query, the alias and the type of the return-class.
Now, the problem is that I just want to return this simple decimal result. This does not map to any of my classes (it's just a primitive that I want to get), so, how do I do this ? What should I use as 3rd argument (the type of the return class) ?

Or, is there any other way to solve this, without to much performance loss ?

Update,

I've just downloaded NHibernate 1.2.0 alpha, and my original problem (with the aggregate query) still exists.

The problem is this:

This is how my HQL looks like:



NHibernate translates this HQL to the following SQL (only the interesting part is pasted here :) ):



Then, NHibernate gives me an exception that says the field with the name x1_0_ cannot be retrieved.
Offcourse not, there is no field x1_0_. You -nhibernate- called it x0_0_ ...

This is very annoying. Now, I always have to work around this, and mostly it is not very performant.

So, I try to work around it using a native SQL query, but there, I'm stuck with this 3rd parameter... what should I give as 3rd parameter (classtype) when I do not want to return a mapped class ?

I've created a ticket for it a while ago...
http://jira.nhibernate.org/browse/NH-555

You can use ADO.NET directly to run SQL returning simple values.

Also, I believe that the bug may be fixed in the current SVN already, but it would be good if you could supply a simple test case for it so I could verify it.

I've sent you an email with a link to a simple sample.

hmm, seems like I forgot to put some comment in my last post. :)

Anyway, I've sent you a simple example for this issue