Here is a partial solution to the problem I encountered (the full solution uses a UNION ALL and the same statement four times):
SELECT
xmlelement( name "bakeware",
xmlconcat(
array_to_string( array_agg(
xmlelement( name "object",
xmlattributes( e.abridge AS "alias" ),
e.name )
), '')::xml
)
)
FROM
recipe.equipment_group eg,
recipe.equipment e
WHERE
eg.label='bakeware' AND
eg.id = e.equipment_group_id
When all four instances are in place (bakeware, cookware, kitchenware, utensils), this produces the following XML code:
<bakeware><object alias="pan">bread pan</object></bakeware>
<cookware/>
<kitchenware><object alias="">bowl (dry)</object><object alias="">bowl (wet)</object></kitchenware>
<utensils/>
A simpler approach would require the following code to work:
xmlconcat( '<a>', '<b/>', '</a>' );
Unfortunately, the XML parser does not recognize that that series of concatenations is well-formed XML.
Is there another approach that I am missing?
Thank you!