Inclusion dependencies for XML

XML has become the de facto standard for representing and interchanging data in internet-based applications. The wide use of XML has necessitated the XML document semantically richer. The integrity constraints play an important role in relational world. And the integrity constraints for XML have been widely investigated over the past few years, especially the functional dependencies and multi-valued dependencies. However, there are few researches on inclusion dependencies for XML (XINDs). In this paper, we propose a novel approach for defning XINDs in XML Schema, which is based on paths. We employ two existing components, selector and field, to locate the information items, which uses restricted XPath as path description language. In particular, we extend the semantics of the field components to support a set (list) of nodes and node with complex type. Related issues are discussed, such as dealing with null values and comparing element nodes with complex type.