Name
XMLELEMENT — Creates XML element
Synopsis
XMLELEMENT
(
|
tag_name varchar , |
list_of_attributes sequence , | |
child_or_attribute1 any , | |
child_or_attribute2 any , | |
... , | |
child_or_attributeN
any
) ; |
Description
XMLELEMENT
takes an element name for identifier, an optional collection of attributes for the element,
and arguments that make up the element's content.
It returns a XML element. The second parameter may be omitted and at that time the
rest parameters may be present. If one of the arguments is a call of the xpath_eval
returning
an attribute value, then this value would be added to element's content (not to element's attributes).
Parameters
tag_name
name of the element, it must be valid XML element name
list_of_attributes
a vector returned by
XMLATTRIBUTES
function. If the vector is NULL, then no attribute is created.
child_or_attributeI
a string, or name of a column, or concatenation of the names and/or strings, or a vector returned by
XMLELEMENT
, XMLFOREST
,
XMLCONCAT
, or XMLAGG
functions,
or an entity object returned by
corresponding functions (e.g. xtree_doc
or xquery_eval
).
If the entity object is an attribute entity, then it is joined
to the list of the element's attributes. If a parameter is NULL, then no child element or attribute is created for
that parameter.
Errors
Table 24.128. Errors signalled by
XMLELEMENT
SQLState | Error Code | Error Text | Description |
---|---|---|---|
22003 | SR354 | Too few arguments for XMLELEMENT | There must be at least one argument |
Examples
Example 24.500. XMLELEMENT() with a single argument
XMLELEMENT
creates an 'Title' element without content.
select XMLELEMENT ('Title') from "Demo"."demo"."Employees"; callret VARCHAR _______________________________________________________________________________ <Title /> <Title /> . . . 9 Rows. -- 2 msec.
Example 24.501. XMLELEMENT() with content
The following example produces an 'Emp' element with three attributes
(the 'region' attribute is calculated by xquery_eval
)
and five nested subelements
select XMLELEMENT ('Emp', XMLATTRIBUTES ( "EmployeeID" AS "EmpID", "Title"), XMLELEMENT ('Name', "FirstName" || ' ' || "LastName" ), xquery_eval('//@region', xtree_doc ('<a region="WA"></a>')), XMLFOREST ("PostalCode", "City" as "city"), XMLCONCAT (XMLELEMENT ('HomePhone', "HomePhone"), XMLELEMENT ('BirthDate', "BirthDate"))) from "Demo"."demo"."Employees" where "EmployeeID"=1; callret VARCHAR _______________________________________________________________________________ <Emp EmpID="1" Title="Sales Representative" region="WA"> <Name>Nancy Davolio</Name> <city>Seattle</city> <PostalCode>98122</PostalCode> <HomePhone>(206) 555-9857</HomePhone> <BirthDate>1948-12-08</BirthDate> </Emp>
Example 24.502. XMLELEMENT() with the aggregate function XMLAGG()
This example produces 'Emp' elements, with the list of the 'Name' of all employees.
select XMLELEMENT ('Emp', XMLAGG (XMLELEMENT('Name', "FirstName", ' ', "LastName"))) from "Demo"."demo"."Employees"; callret VARCHAR _______________________________________________________________________________ <Emp> <Name>Nancy Davolio</Name> <Name>Andrew Fuller</Name> <Name>Janet Leverling</Name> <Name>Margaret Peacock</Name> <Name>Steven Buchanan</Name> <Name>Michael Suyama</Name> <Name>Robert King</Name> <Name>Laura Callahan</Name> <Name>Anne Dodsworth</Name> </Emp>