The Document Access Definition (DAD) file is an XML document that provides control over the mapping of XML documents to a DB2 database for both storage and retrieval. The DADX file is an extension of the XML Extender DAD file and includes standard SQL functionality that does not use the XML Extender. DADX enables the creation of Web services that store and retrieve XML documents managed by XML Extender. A DADX file specifies how to create a Web service using a set of operations that are defined by SQL statements, and optionally DAD files.
The DADX defines the operations that can be performed by the Web service. DADX files contain both XML-based and SQL-based operations as described below.
XML-Based Operations
XML-based operations include:
An XML-based query enables you to compose XML documents from relational data. An XML document is broken down into its component parts and stored in relational tables. A mapping file, called a DAD file, creates the association between the relational data and the XML document structure. The user-defined mapping of SQL data to XML elements and attributes requires DB2 XML Extender.
SQL-Based Operations
SQL-based operations include:
SQL-based query allows you to send SQL statements, including stored procedure calls, to DB2 and to return the results with a default tagging. SQL-based operations do not require DB2 XML Extender since there is no user-defined mapping of SQL data to XML elements and attributes. Data is returned using only a simple mapping of SQL data types, using column names as elements.