Muokkaa

Jaa

Applying an XSLT Transform to a DataSet

  • Artikkeli

The WriteXml method of the DataSet enables you to write the contents of a DataSet as XML data. A common task is to then transform that XML to another format using XSL transformations (XSLT). However, synchronizing a DataSet with an XmlDataDocument enables you to apply an XSLT stylesheet to the contents of a DataSet without having to first write the contents of the DataSet as XML data using WriteXml.

The following example populates a DataSet with tables and relationships, synchronizes the DataSet with an XmlDataDocument, and writes a portion of the DataSet as an HTML file using an XSLT stylesheet. The following are the contents of the XSLT stylesheet:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">  
  
<xsl:template match="CustomerOrders">  
  <HTML>  
  <STYLE>  
  BODY {font-family:verdana;font-size:9pt}  
  TD   {font-size:8pt}  
  </STYLE>  
    <BODY>  
    <TABLE BORDER="1">  
      <xsl:apply-templates select="Customers"/>  
    </TABLE>  
    </BODY>  
  </HTML>  
</xsl:template>  
  
<xsl:template match="Customers">  
    <TR><TD>  
      <xsl:value-of select="ContactName"/>, <xsl:value-of select="Phone"/><BR/>  
    </TD></TR>  
      <xsl:apply-templates select="Orders"/>  
</xsl:template>  
  
<xsl:template match="Orders">  
  <TABLE BORDER="1">  
    <TR><TD valign="top"><B>Order:</B></TD><TD valign="top"><xsl:value-of select="OrderID"/></TD></TR>  
    <TR><TD valign="top"><B>Date:</B></TD><TD valign="top"><xsl:value-of select="OrderDate"/></TD></TR>  
    <TR><TD valign="top"><B>Ship To:</B></TD>  
        <TD valign="top"><xsl:value-of select="ShipName"/><BR/>  
        <xsl:value-of select="ShipAddress"/><BR/>  
        <xsl:value-of select="ShipCity"/>, <xsl:value-of select="ShipRegion"/>  <xsl:value-of select="ShipPostalCode"/><BR/>  
        <xsl:value-of select="ShipCountry"/></TD></TR>  
  </TABLE>  
</xsl:template>  
  
</xsl:stylesheet>

The following code fills the DataSet and applies the XSLT style sheet.

Note

If you are applying an XSLT style sheet to a DataSet that contains relations, you achieve best performance if you set the Nested property of the DataRelation to true for each nested relation. This allows you to use XSLT style sheets that implement natural top-down processing to navigate the hierarchy and transform the data, as opposed to using performance-intensive XPath location axes (for example, preceding-sibling and following-sibling in style sheet node test expressions) to navigate it. For more information on nested relations, see Nesting DataRelations.

' Assumes connection is a valid SqlConnection.  
Dim dataSet As DataSet = New DataSet("CustomerOrders")  
  
Dim customerAdapter As SqlDataAdapter = New SqlDataAdapter( _  
  "SELECT * FROM Customers", connection)  
customerAdapter.Fill(dataSet, "Customers")  
  
Dim orderAdapter As SqlDataAdapter = New SqlDataAdapter( _  
  "SELECT * FROM Orders", connection)  
orderAdapter.Fill(dataSet, "Orders")  
  
connection.Close()  
  
dataSet.Relations.Add("CustOrders", _  
dataSet.Tables("Customers").Columns("CustomerID"), _  
dataSet.Tables("Orders").Columns("CustomerID")).Nested = true  
  
Dim xmlDoc As XmlDataDocument = New XmlDataDocument(dataSet)
  
Dim xslTran As XslTransform = New XslTransform  
xslTran.Load("transform.xsl")  
  
Dim writer As XmlTextWriter = New XmlTextWriter( _  
  "xslt_output.html", System.Text.Encoding.UTF8)  
  
xslTran.Transform(xmlDoc, Nothing, writer)  
writer.Close()  

// Assumes connection is a valid SqlConnection.  
connection.Open();  
  
DataSet custDS = new DataSet("CustomerDataSet");  
  
SqlDataAdapter customerAdapter = new SqlDataAdapter(  
  "SELECT * FROM Customers", connection);  
customerAdapter.Fill(custDS, "Customers");  
  
SqlDataAdapter orderAdapter = new SqlDataAdapter(  
  "SELECT * FROM Orders", connection);  
orderAdapter.Fill(custDS, "Orders");  
  
connection.Close();  
  
custDS.Relations.Add("CustOrders",  
  custDS.Tables["Customers"].Columns["CustomerID"],  
                     custDS.Tables["Orders"].Columns["CustomerID"]).Nested = true;  
  
XmlDataDocument xmlDoc = new XmlDataDocument(custDS);
  
XslTransform xslTran = new XslTransform();  
xslTran.Load("transform.xsl");  
  
XmlTextWriter writer = new XmlTextWriter("xslt_output.html",
  System.Text.Encoding.UTF8);  
  
xslTran.Transform(xmlDoc, null, writer);  
writer.Close();

See also