Declarative XML Update Language Based on a Higher Data Model

With the extensive use of XML in applications over the Web, how toupdate XML data is becoming an important issue because the role ofXML has expanded beyond traditional applications in which XML isused for information exchange and data representation over theWeb. So far, several languages have been proposed for updating XMLdata, but they are all based on lower, so-called graph-based ortree-based data models. Update requests are thus expressed in anonintuitive and unnatural way and update statements are toocomplicated to comprehend. This paper presents a noveldeclarative XML update language which is an extension of theXML-RL query language. Compared with other existing XML updatelanguages, it has the following features. First, it is the onlyXML data manipulation language based on a higher data model.Second, this language can express complex update requests atmultiple levels in a hierarchy in a simple and flat way. Third,this language directly supports the functionality of updatingcomplex objects while all other update languages do not supportthese operations. Lastly, most of existing languages userename to modify attribute and element names, which is adifferent way from updates on value. The proposed language modifies tagnames, values, and objects in a unified way by the introduction ofthree kinds of logical binding variables: object variables,value variables, and name variables.