XQuery, the standard query language for XML, is gaining popularity among users with a SQL background; indeed, formulating XQuery and SQL queries requires comparable skills. However, this nucleus of programmers is not vast, and the availability of simpler XQuery “dialects ” could be valuable for establishing its success. With this motivation in mind, we designed XQBE, a visual dialect of XQuery inspired by QBE (Query by Example). QBE was initially proposed as alternative to SQL and has gained popularity as the language supported by MS Access, currently presented to users with a very limited experience of query languages. Coherent with the XML data model, XQBE uses one or more hierarchical structures to denote the input XML documents and one structure to denote the output document. Similar to QBE, structures are annotated to express selection predicates; explicit bindings between these structures visualize the input/output mappings. 1
