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.
See Also:
"XML Format Model" for a description of theXMLFormat
type and how to use its attributes to format SYS_XMLGen
resultsThe 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) ------------------------------------------------------------------- <?xml version="1.0"?> <EMAIL>SHIGGINS</EMAIL>