XQBE

Abstract

XQBE (XQuery By Example) is a visual XML query language which, coherently with the hierarchical XML data model, uses tree-shaped structures to express queries and transformations over XML documents. These structures are annotated to express selection predicates; explicit bindings between the nodes of such structures visualize the input/output mappings.XQuery and XSLT, the standard query and transformation languages for XML, happen to be too complex for most occasional or unskilled users who might need to specify queries, schema mappings, or document transformations, if they are only aware of the basics of the XML data model. The implementation of XQBE allows to generate the XQuery and XSLT translations of the visual queries, assisting the user in several aspects of the interaction (e.g. providing interactive access to schema information); therefore, XQBE provides an integrated environment where users can edit the visual queries and their textual counterparts, executing them on several engines. Alternating among different representations of the same query is valuable for training beginners, as we have experienced in our database courses.