1. A method for data query comprising: providing a data schema having a data schema query language associated therewith; providing an ontology model including classes and properties, the ontology model having an ontology query language associated therewith, wherein constructs of the data schema are mapped to corresponding classes, properties or compositions of properties of the ontology model; providing a query expressed in the ontology language; generating a query expressed in the data schema query language corresponding to the query expressed in the ontology query language; providing an additional data schema having an additional data schema query language associated therewith, wherein constructs of the additional data schema are also mapped to corresponding classes, properties or compositions of properties of the ontology model; and generating a query expressed in the additional data schema query language corresponding to the query expressed in the ontology query language.