XQBE: A Graphical Interface for XQuery Engines

XQuery is increasingly popular among computer scientists with a SQL background, since queries in XQuery and SQL require comparable skills to be formulated. However, the number of these experts is limited, and the availability of easier XQuery “dialects” could be extremely valuable. Something similar happened with QBE, initially proposed as an alternative to SQL, that has then become popular as the user-friendly query language supported by MS Access. We designed and implemented XQBE, a visual dialect of XQuery that uses hierarchical structures, coherent with the hierarchical nature of XML, to denote the input and output documents. In this demonstration we brie¤y introduce XQBE; we then describe how our implementation generates the XQuery translation of the visual queries and also how the XQBE translation of an XQuery statement is generated, provided that XQBE is expressive enough for that query.