<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Introduction</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="book.sdo-das-xml.html">SDO DAS XML</a></div> <div class="next" style="text-align: right; float: right;"><a href="sdo-das-xml.setup.html">Installing/Configuring</a></div> <div class="up"><a href="book.sdo-das-xml.html">SDO DAS XML</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="intro.sdo-das-xml" class="preface"> <h1 class="title">Introduction</h1> <p class="para"> In order to use the XML Data Access Service for Service Data Objects, you will need to understand some of the concepts behind SDO: the data graph, the data object, XPath and property expressions, and so on. If you are not familiar with these ideas, you might want to look first at <a href="ref.sdo.html" class="link">the section on SDO</a>. </p> <p class="para"> The job of the XML DAS is to move data between the application and an XML data source, which can be either a file or a URL. SDOs are always created and maintained according to a model which defines type names and what property names each type may have. For data which is from XML, this SDO model is built from a schema file written in XML schema language (an xsd file). This schema file is usually passed to the create method when the XMLDAS is initialised. The <a href="http://www.ibm.com/developerworks/webservices/library/specification/ws-sdo/" class="link external">» SDO 2.0 specification</a> defines the mapping between XML types and SDO types. There are a number of small limitations in the PHP support - not everything which is in the specification can be done - and these limitations are summarised in a later section. </p> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="book.sdo-das-xml.html">SDO DAS XML</a></div> <div class="next" style="text-align: right; float: right;"><a href="sdo-das-xml.setup.html">Installing/Configuring</a></div> <div class="up"><a href="book.sdo-das-xml.html">SDO DAS XML</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>
