GLASS: a graphical query language for semi-structured data

The increase in the use of XML (eXtensible Markup Language) makes the semistructured data more and more important on the Web. To exploit the full power of XML documents, a query language for semistructured data will be a promising and interesting application. However, the XQuery standard released by W3C is too difficult for common users to use. Some XML graphical query languages for semistructured data have been proposed but they are either too complex or too limited in use. We introduce a graphical query language for semistructured data, which we call GLASS. GLASS is developed on the base of ORA-SS data model, a semantically richer data model for semistructured data In GLASS, we combine the advantages of graphs and texts, which make the graphical language much clear and easy to use. The paper presents the notations and basic capabilities of GLASS via a series of examples with increasingly complexity. We also discuss some complex query examples such as order, group entity, negation and IF-THEN statement.