HQL - find entity where property x is highest

Question

Can HQL queries do this?

"get the UserEntity where the property creationTimestamp is the most recent of all UserEntities".

Essentially a query to return the "newest user" in our program where each UserEntity has a field mapped to a timestamp column in our database.

Answer 1

Have you looked at the HQL order-by clause?

Answer 2

The HQL query to list the users from newest first is:

from UserEntities
order by creationTimestamp desc

Use setMaxResults to limit the result set to just one user.

Answer 3

Querying for the highest creationTimestamp would look like this:

from UserEntity where creationTimestamp = max(creationTimestamp)

If you want to return only a single instance and ignore other results that have the same (highest) value on that property, you can use query.uniqueResult().

See Chapter 14. HQL: The Hibernate Query Language for further reference.