Querying XML

Chapter 14

XQuery APIs

14.1 Introduction

In the last few chapters, you read about XQuery 1.0 and XPath 2.0, languages for querying XML documents, collections, and fragments. But a query language cannot stand alone – it must run in some context. You will read in Chapter 15, “SQL/XML,” that the SQL/XML extensions provide an ideal harness for running XQueries in the context of a SQL database. In this chapter, we focus on a more generic XQuery context, the Java context, and describe the proposed JCP standard XQJ.¹ The architecture of XQJ follows that of JDBC^® (XQJ has been called “JDBC for XQuery”), which in turn follows ODBC. (See Section 14.2.1 for a description of ODBC and JDBC.)

After describing XQJ, we compare it to SQL/XML as an XQuery API. ...