Query Wrapper Language Over Sql

Some claim that HibernateQueryLanguage makes cross-platform querying easier, and provides some shortcuts over SQL. Although HibernateQueryLanguage is mostly for Java, I wonder if the concept cannot be extended outside of Java and OOP languages.

Would it be worth it to wrap SQL with another query language? Would it really provide smooth cross-database transitions? Can it really improve upon SQL even outside of cross-platform issues?