Beginning XML Databases (Wrox Beginning Guides)

In this chapter you learned that:

• XQuery commands are not written in XML.

• XQuery can be used to query XML data.

• XQuery has capabilities similar to a primitive form of SQL.

• XPath and XQuery share many components , especially functions and axes.

• Saxon is a very simple-to-use shell tool for executing XQueries.

• XQuery commands can be embedded with HTML text and tags.

• XQuery commands can be embedded with XML tags.

• XQuery terminology and syntax is common to much of XML.

• XQuery has a for loop called FLWOR.

• FLWOR represents For, Let, Where, Order By, and Return.

• A for loop iterates through a collection (sequence) of sibling nodes.

• The FLWOR where clause filters out data.

• The FLWOR order by clause resorts data.

• The FLWOR return clause restricts what is returned from a for loop collection.

• XQuery and XPath allow construction of user -defined functions.

• Oracle Database has a specialized suite of capabilities it calls Oracle XML DB (Oracle XML Database).

• Oracle XML DB includes various functions allowing transformation between XML and relational data.