SYS_XMLGEN

Syntax

sys_xmlgen::=

Description of the illustration sys_xmlgen.gif


Purpose

SYS_XMLGen takes an expression that evaluates to a particular row and column of the database, and returns an instance of type 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, then the function returns an XML element containing the scalar value.

• If expr is a type, then 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, then the enclosing XML element will be the same column name. If you want to format the XML document differently, then specify fmt, which is an instance of the XMLFormat object.

Examples

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)      
   FROM employees
   WHERE employee_id = 205;

SYS_XMLGEN(EMAIL)
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<EMAIL>SHIGGINS</EMAIL>