CRITICAL SKILL 8.6 Create a Relational View from XML

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Project Summary

This project illustrated the use of existsnode(), extract(), and extractvalue() when identifying an XML document stored in the Oracle Database 10g.

In the future, Oracle is looking at adding several new capabilities to this list, including additional database and XML functionalities, such as XQuery, which will be a language specifically designed to query XML data from a document perspective rather than the rows-and-tables perspective of SQL. We have had fun finding and returning XML documents. Let's proceed and look at how we can take XML documents and represent them relationally.

Progress Check

1. Is the Oracle XML DB repository separate from the Oracle Database 10g?

2. Why must we ''register" the URL of XML Schemas into the Oracle XML DB repository?

3. How do we load an XML document into the Oracle XML DB repository?

4. What is the difference between the existsnode() function and the extract() function?

CRITICAL SKILL 8.6
Create a Relational View from XML

Oracle XML DB makes it possible to expose XML content, stored in the database through conventional relational views. This means that tools, applications, and programmers who have no understanding of XML, but understand the Oracle Database 10g, can now work with XML content. To accomplish this, the view

Progress Check Answers

1. No, the Oracle XML DB is integrated with Oracle Database 10g.

2. The XML Schema defines the legal structure for an XML document. To confirm that the XML stored within the XMLType is "valid," the URL for the XML Schema it is associated with must be registered.

3. XML documents can be loaded into the Oracle XML DB via programs using SQL, PL/SQL, and Java or by going through the protocols FTP, HTTP, and WebDAV.

4. The existsnode() function identifies the existence of a node returning a Boolean value, while the extract() function extracts the node or set of nodes identified, returning a single text node.

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