Re: xml output

On 25 August 2010 09:53, Florian Henge <florian(dot)henge82(at)web(dot)de> wrote:
> Hi!
>
> Thanks, that worked perfectly for me, except for one problem.
>
> I have like 20 times the name "Joe" in my table, but want to get it only once in the xml output file.
>
> How can is do this? I tried SELECT DISTINCT but it didn't work.

If you're using PostgreSQL 8.4 or greater you can do:

WITH people AS (
SELECT DISTINCT first_name
FROM person
ORDER BY first_name
)
SELECT
xmlelement(name words,
xmlagg(
xmlforest(first_name)
)
)
FROM people

If not, you can do:

SELECT
xmlelement(name words,
xmlagg(
xmlforest(first_name)
)
)
FROM (
SELECT DISTINCT first_name
FROM person
ORDER BY first_name
) AS people

Although maybe there's a nicer way of doing it. Note that if you want
aggregates in your results, use GROUP BY instead of DISTINCT.
--
Thom Brown
Registered Linux user: #516935