A repository may support query. The structure and evaluation semantics of a query are defined by an abstract query model (AQM) for which two concrete language bindings are specified: JCR-SQL2, which expresses a query as a string with syntax similar to SQL, and JCR-JQOM (JCR Java Query Object Model), which expresses a query as a tree of Java objects. The languages are both direct mappings of the AQ