IT420: Database Management and Organization

1. IT420: Database Management and Organization XML 21 April 2006 Adina Crainiceanu www.cs.usna.edu/~adina

2. Kroenke, Database Processing 2 Overview From HTML to XML DTDs Transforming XML: XSLT

3. Kroenke, Database Processing 3 Introduction Database processing and document processing need each other Database processing needs document processing for transmitting/ expressing database views Document processing needs database processing for storing and manipulating data Internet expansion made the need obvious As Internet usage increased, organizations wanted to make their Web pages more functional by displaying and updating data from organizational databasesAs Internet usage increased, organizations wanted to make their Web pages more functional by displaying and updating data from organizational databases

4. Kroenke, Database Processing 4 XML XML: Extensible Markup Language, developed in early 1990s Hybrid of document processing and database processing It provides a standardized yet customizable way to describe the content of documents A recommendation from the W3C XML = data + structure XML generated by applications XML consumed by applications Easy access: across platforms, organizations Hybrid of document processing and database processing It provides a standardized yet customizable way to describe the content of documents XML documents can automatically be generated from database data, and vice versa Hybrid of document processing and database processing It provides a standardized yet customizable way to describe the content of documents XML documents can automatically be generated from database data, and vice versa

5. Kroenke, Database Processing 5 XML What is this? What does it mean? <h2>Madison</h2> HTML: How to display information on a browser. HTML: no �semantic� information, i.e. no meaning ascribed to tags

6. Kroenke, Database Processing 6 XML: Semantic information <presidents> <name>Madison</name> <US_cities> <Wisconsin> <name>Madison</name> <US_Colleges> <name>Madison, U of Wisc</name> <name> Madison, James (JMU)</name>

7. Kroenke, Database Processing 7 XML vs. HTML XML is better than HTML because It provides a clear separation between document structure content materialization It is standardized but allows for extension by developers XML tags represent the semantics of their data

8. Kroenke, Database Processing 8 Why is XML important with regard to databases? XML provides a standardized way to describe, validate, and materialize any database view. Share information between disparate systems Materialize data anyway you want Display data on web Display data on sales-person computer Display data on mobile device

9. Kroenke, Database Processing 9 How does XML work? Three Primary Components to XML Data has a structure Document Type Declarations (DTDs) XML Schemas can be used to describe the content of XML documents Data has content XML document Data has materializations Extensible Style Language: Transformations (XSLT)

10. Kroenke, Database Processing 10 If we want to share information is structure important? Structure provides meaning