SYS_XMLGEN

Syntax

sys_xmlgen::=

Text description of sys_xmlgen

Purpose

The SYS_XMLGEN function takes an expression that evaluates to a particular row and column of the database, and returns an instance of type SYS.XMLType containing an XML document. The expr can be a scalar value, a user-defined type, or an XMLType instance.

• If expr is a scalar value, the function returns an XML element containing the scalar value.

• If expr is a type, the function maps the user-defined type attributes to XML elements.

• If expr is an XMLType instance, then the function encloses the document in an XML element whose default tag name is ROW.

By default the elements of the XML document match the elements of expr. For example, if expr resolves to a column name, the enclosing XML element will be the same column name. If you want to format the XML document differently, specify fmt, which is an instance of the SYS.XMLGenFormatType object.

See Also: "XML Format Model" for a description of the XMLGenFormatType type and how to use its attributes to format SYS_XMLGEN results Oracle9i XML Reference and Oracle9i Application Developer's Guide - XML for information on XML types and their use

Example

The following example retrieves the employee email ID from the sample table oe.employees where the employee_id value is 205, and generates an instance of an XMLType containing an XML document with an EMAIL element.

SELECT SYS_XMLGEN(email).getStringVal()      
   FROM employees
   WHERE employee_id = 205;

SYS_XMLGEN(EMAIL).GETSTRINGVAL()
------------------------------------------------------------------
<EMAIL>SHIGGENS</EMAIL>

Note: XMLType data is treated the same as CLOB data, which cannot be displayed using SQL*Plus. Therefore, this example appends the XMLType.getClobVal method to the function in order to view the actual document. This method is not necessary, for example, if you are inserting an XMLType value into a database.