Question

We are using Oracle 10g database, NHibernate, WCF and Silverlight 3.0 in our project
The situation we have is that the entities in my project have many properties. But for certain situations, like showing the options in dropdown, I only want to retrieve the list of ID and Name field for that entity. I do not want to return a list of the entire entity object as a whole as there are many columns in the table. Presently I am using two SELECT queries: one to fetch the list of IDs and second to fetch the list of Names separately. Then I join these two queries and form a Dictionary and pass it to the UI.

The concern for me is that would it be possible to achieve this in a single query itself?

One approach that I know of is to create a new class having only the ID and Name property, import it into NHiberante and then form a list of this new class and send it to the UI. I want to avoid this approach for now as there are many tables for which I have to implement this functionality and hence I will have to create many new classes and corresponding xml files.

Any sort of help would be greatly appreciated.

Answer 1

Here is one way to do it using the Criteria API, Projections and AliasToBean. If it’s a simple non-persistent class containing Id and Name you can reuse the class. NHibernate query CreateCriteria