Accessing Data Using XML CHAPTER NINE Matakuliah: T0063 – Pemrograman Visual Tahun: 2009

Bina Nusantara University 2 Introduction The eXtensible Markup Language (XML) is a language used to represent data in a form that does not rely on any particular proprietary technology. XML Schema provides a way of defining and validating XML documents. eXtensible Stylesheet Language (XSL) and eXtensible Stylesheet Language Transforms (XSLT) is another useful technology associated with XML.

Bina Nusantara University 3 Introduction (cont.) This capability enables you to take a single XML document and transform it into a variety of different versions for specific uses. A number of classes within Visual Basic.NET provide methods that work directly with XML. Microsoft’s.NET initiative uses XML as its foundation data technology.

Bina Nusantara University 4 Objectives Understand what XML is and how it is used within business-to-business transactions. Understand XML Schemas and XSL Transforms and how they are used within the context of XML. Read and process data that are stored in an XML document.

Bina Nusantara University 5 Objectives (cont.) Read data from a relational database and transform them into their equivalent XML. Transform one XML document into a new XML document using an XSLT document.

Bina Nusantara University An XML Primer What is XML? –XML provides a technology-neutral way to represent data. –XML is rapidly becoming the data format “standard” for the exchange of data on the Internet. –Data content and data presentation are separate. –Data represent what is called a tree.

Bina Nusantara University An XML Primer (cont.) XML Syntax –The language is case sensitive. –There is one and only one root node. –All elements have a start tag and an end tag. –Tags must be nested correctly. –Attributes must be quoted. An XML document is well formed if you follow the above rules.

Bina Nusantara University An XML Primer (cont.) –Namespaces A namespace defines a point of reference. –Change the element tag by adding a prefix and a colon to the tag. –Ex. and. Can differentiate two tags within the same document. Syntax: xmlns:name = “uri” The uri (Uniform Resource Identifier) is a unique identifier.

Bina Nusantara University An XML Primer (cont.) –Document Prolog Indicates that the document is XML as well as other things such as document type, entity definitions and other processing instructions.

Bina Nusantara University An XML Primer (cont.) XML Schemas –Rules that define legal elements, tags, and content. –Used to determine the validity of a document. –Industry specific XML schemas are being developed.

Bina Nusantara University An XML Primer (cont.) Styling XML –Extensible Stylesheet Language Transforms (XSLT) provide a way to transform one XML document to another XML document.

Bina Nusantara University Creating XML Documents and XML Schemas Using Visual Basic.NET Creating an XML Schema –Add an XML Schema to a project by selecting Add New Item from the File menu. –Use tools from the Toolbox to create the schema. –Save the Schema definition.

Bina Nusantara University Creating XML Documents and XML Schemas Using Visual Basic.NET (cont.) Creating an XML Document –Complete the examples listed below in your textbook: Example 9.1 Using Simple and Complex Data Types in XML Schemas. Example 9.2 Creating Nested Relationships in an XML Schema. Example 9.3 Creating Tables with Relationships in an XML Schema. Example 9.4 Transforming XML using XSLT.

Bina Nusantara University Using ADO.NET with XML ADO.NET provides a number of useful classes and methods to work directly with XML documents. –Data are already in XML form. This section provides a number of examples that demonstrate XML capabilities of the ADO.NET framework.

Bina Nusantara University Using ADO.NET with XML (cont.) Complete the following examples listed below in your textbook: –Example 9.5 Processing an XML Document. –Example 9.6 Converting Relational DB Data into XML. –Example 9.7 Using XML and XSLT to Transform Data from a Relational Database.