Oracle® Database SQL Language Reference 11g Release 1 (11.1) Part Number B28286-01 |
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Syntax
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.
See Also:
"XML Format Model" for a description of the XMLFormat
type and how to use its attributes to format SYS_XMLGen
results
Oracle Database Concepts for an overview of XML types and their use
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) ------------------------------------------------------------------- <EMAIL>SHIGGINS</EMAIL>