Example: Using XSLT for data exchange

This example illustrates how to use the built-in XSLTRANSFORM function to convert XML documents for data exchange.

This example uses parameters with the stylesheet to produce different data exchange formats at runtime.

We use a stylesheet that incorporates xsl:param elements to capture data from a parameter file.

INSERT INTO Display_productdetails values(1, '<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:param name="headline"/>
<xsl:param name="supermarketname"/>
<xsl:template match="product">
   <html>
             <head/>
                <body>
                <h1><xsl:value-of select="$headline"/></h1>
                <table border="1">
                        <th>
                        <tr>
                         <td width="80">product ID</td>
                         <td width="200">product name</td>
                         <td width="200">price</td>
                         <td width="50">details</td>
                         <xsl:choose>
   <xsl:when test="$supermarket =''true'' ">
                                 <td width="200">BIG BAZAAR super market</td>
                                </xsl:when>
    </xsl:choose>
                         </tr>
                        </th>
                        <xsl:apply-templates/>
                </table>
                </body>
                </html>
        </xsl:template>
      <xsl:template match="product">
             <tr>
                   <td><xsl:value-of select="@pid"/></td>
                   <td><xsl:value-of select="/product/description/name"/></td>
                   <td><xsl:value-of select="/product/description/price"/></td>
                   <td><xsl:value-of select="/product/description/details"/></td>
                  </tr>
     </xsl:template>
  </xsl:stylesheet>'
);

The parameter file contains parameters corresponding to the ones in the XSLT template, with content:

CREATE TABLE PARAM_TAB (DOCID INTEGER, PARAM VARCHAR (10K));

INSERT INTO PARAM_TAB VALUES
(1,
'<?xml version="1.0"?>
<params xmlns="http://www.ibm.com/XSLTransformParameters">
        <param name="supermarketname" value="true"/>
        <param name="headline">BIG BAZAAR super market</param>
</params>'
);

You can then apply the parameter file at runtime using the following command:

SELECT XSLTRANSFORM (XML_DOC USING XSL_DOC WITH PARAM AS CLOB (1M)) 
   FROM product_details X, PARM_TAB P WHERE X.DOCID=P.DOCID;

The result is HTML, but with content determined by the parameter file and tests done against the content of the XML document:

<html>
<head>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<h1></h1>
<table border="1">
<th>
<tr>
<td width="80">product ID</td>
<td width="200">product Name</td>
<td width="200">price</td>
<td width="50">Details</td>
</tr>
</th> 
</table>
</body>
</html>

In other applications, the output of XSLTRANSFORM might not be HTML but rather another XML document or a file using a different data format, such as an EDI file.

For data exchange applications, the parameter file could contain EDI or SOAP file header information such as e-mail or port addresses, or other critical data unique to a particular transaction. Since the XML used in the above examples is an inventory record, it is easy to imagine using XSLT to repackage this record for exchange with a client's purchasing system.