Is it possible to use casts in JPQL? In HQL it seems to be supported
cast(... as ...), where the second argument is the name of a Hibernate type, and extract(... from ...) if ANSI cast() and extract() is supported by the underlying database
source : Hibernate reference
My target JPA provider is EclipseLink, so any EclipseLink specific solution is ok as well.
According to the specification of JPA/JPA2, JPQL is not supporting query casts. However, the most recent EclipseLink Release 2.1.0 does have a propritary support for downcasts in JPQL and expressions, please look here
Literal downcasts in EclipseLink JPQL are currently not supported, but might be if the following issue gets resolved : https://bugs.eclipse.org/bugs/show_bug.cgi?id=315087