Is it possible to write an HQL query (or barring that, a Criteria query) that joins hibernate-mapped classes against a table not mapped by hibernate?

My use case is, for analysis and reporting purposes, I will pre-compute the primary keys of entities I'm interested in for a particular analysis, and store these in a temporary table that I'd like to join against for many queries

So, can I do the equivalent of


I assume that Restrictions.sqlRestriction will let me do this for a Criteria query, but I'd much prefer to be able to use HQL. Thoughts?

Hi,
It is not possible to mix SQL and HQL in the same query: http://stackoverflow.com/questions/1538577/mix-hql-and-sql-in-the-same-query

If you don't want to run an SQL query, I think that you can map the temp table as immutable entities: https://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html_single/#readonly-api-immutable
or, maybe, you can use the @Formula annotation to store the value that you need in a property of an entity.

Cheers,
Davide

Davide,

Thanks for the response.

Would you mind expanding a bit more on how mapping the temp table as an immutable entity would work?

My intention was to create a temp table on the fly at run-time, and drop it after the analysis is complete. Are you suggesting that I could programmatically define a new entity mapping (as an immutable entity) while the system is running?

Thanks,
Darius

> Are you suggesting that I could programmatically define a new entity mapping (as an immutable entity) while the system is running

I'm not sure about this but hibernate should see a temp table like any other table (as long as you already know in advance the name of the table and the columns it will have), the only difference is that you are only interested to read the values from it .
I think this might work as long as you execute the query when the table exists.

Currently, I don't think you can define on entity on the fly.