XAML is a markup language used to define dynamic or static UIs for .NET applications. Though Windows Vista would be used to design XAML UIs, they can be applied to Windows XP or Windows 2003 too.

XAML is similar to MVC in terms of the separation of the UI code from application logic.

XAML is bound to Windows Presentation foundation to build a UI in .NET 3.0 and Windows Vista.

XAML Features:

- XAML inherits all XML definitions and rules.

- It also contains HTML, XHTML and other markup languages for UI.

- Every XAML element represents a .NET CLR class due to which working with XAML becomes simple.

- The application logic can be put in a separate file or be embedded in XAML file itself as XAML in conjunction with Windows Presentation Foundation model to provide the developers design a good UI in ASP.NET.

- XAML files get compiled to BAML files which are smaller than XAML and easier to read which make them faster to load.

SQL Server is having a fantastic feature to retrieve data persisted in the form of XML format. The data in the XML format can be retrieved using FOR XML clause appending to the SELECT statement.

It offers 3 modes.

- “FOR XML AUTO": Returns XML elements that are nested, based on which tables are listed in the "from" part of the query, and which fields are listed in the "select" part.

- "FOR XML RAW": Returns XML elements with the "row" prefix (ex: ""). Each column in a table is represented as an attribute and null column values aren't included.

- "FOR XML EXPLICIT": Explicit mode is the most complex shaping method used in SQL Server 2000. It allows users to query a data source in such a way that the names and values of the returned XML are specified before the query batch is executed. 

XPath specifies the path in the XML document which has hierarchical elements. XPath is used with XPointer and XSLT and parser.  

XML templates are XML files such as XHTML files. XML templates includes the processing directives which affect how the template is rendered, and the template expressions which are substituted dynamically by various data.

Parsing the XML document is the only way to validate the XML file. Validation is done by either DOM parser or the SAX parser. 

You need to first create a table in oracle that matches with the fields of the XML data.

So to get the XMl into the table, you can create a generic procedure that moves an XML document into a table by converting the elements to Oracle Canonical format.

Oracle Canonical format is as follows:

<ROWSET>

   <ROW>  

     <column_name_1 />

     .

     .

     </ROW>

     <ROW>

         <column_name_1 />

         .

         .

      </ROW> 

        .

        .

</ROWSET>        

ROW is used for the table names

ROWSET is used for the XML document

You can get the XML into the canonical form using XSL:

<?xml version="1.0"?>

<xsl:stylesheet 

             xmlns:xsl="https://www.w3.org/1999/XSL/Transform"                   

             version="1.0">

     <xsl:template match="/">

          <ROWSET>

               <ROW>

                         <Attribute_name>                      

                             <xsl:value-of select="Table_name/Attribute_name" />

                         </Attribute_name>

                < /ROW>

          </ROWSET>

     </xsl:template>

</xsl:stylesheet>

To transform the XML document into the canonical form, you can write a procedure. Make sure you include the line below in your procedure code:

v_rows := DBMS_XMLStore.insertXML(

                v_context,    

                XMLType.transform(p_xml_in, p_xsl_in));

The only remaining step is calling your procedure: 

DECLARE

   v_xml XMLType := XMLType( YOUR XML Document );

   v_xsl XMLType := XMLType( YOUR XSL Document );

BEGIN 

   procedure_name(v_xml, v_xsl, 'table_name');

END;

An XSL sheet or a document may have duplicate elements and attributes. Therefore, the XML namespaces define a way to distinguish between duplicate element types and attribute names.

An XML namespace is a collection of element type and attribute names. It is a URI due to which any element type or attribute name in an XML namespace can be uniquely identified. 

It consists of two parts : the name of the XML namespace and the local name.

e.g.: xmlns: h=”https://www.abc.com”

After this, you can write

<h:table>

……..

</h:table>

to associate the table with the declared namespace. 

CDATA - (Unparsed) Character Data

The term CDATA is used when you dont want some text data to be parsed by the XML parser.

A CDATA section starts with "<![CDATA[" and ends with "]]>":