Recursive function that receives a list of IDs and returns all child IDs

"Sven Haag" <sven-haag@gmx.de> writes:

hello pgsql fans out there,
i've already created a function that returns a list of IDs of all sub-samples based on a given sample ID. this works fine. now i like to extend this function so that it can receive a list of sample IDs. e.g.:

fn_get_subsamples(IN sample_numbers SETOF integer)

There's no such animal as a function that accepts a set. You could pass
it an array of integers instead. Or maybe just call it more than once.

regards, tom lane

i guess an array is also ok. must been something like:
fn_get_subsamples(IN sample_numbers[] integer) ??

how would a query then look like?

SELECT * FROM sample WHERE sample_number IN ( fn_get_subsamples(1,2,3,4)
) ??

cheers sven

Am 23.03.2011 17:42, schrieb Tom Lane:

i guess an array is also ok. must been something like:
fn_get_subsamples(IN sample_numbers[] integer) ??

how would a query then look like?

SELECT * FROM sample WHERE sample_number IN ( fn_get_subsamples(1,2,3,4)
) ??

cheers sven

Am 23.03.2011 17:42, schrieb Tom Lane:

On Wed, Mar 23, 2011 at 10:29 AM, Sven Haag <sven-haag@gmx.de> wrote:

hello pgsql fans out there,

i've already created a function that returns a list of IDs of all sub-samples based on a given sample ID. this works fine. now i like to extend this function so that it can receive a list of sample IDs. e.g.:

fn_get_subsamples(IN sample_numbers SETOF integer)

here is the existing function:

CREATE OR REPLACE FUNCTION fn_get_subsamples(IN sample_number integer)
 RETURNS SETOF integer AS
$BODY$
       WITH RECURSIVE recursetree(sample_number) AS (
         SELECT sample_number
         FROM sample
         WHERE parent_sample = $1

         UNION ALL

         SELECT t.sample_number
         FROM sample t
         JOIN recursetree rt ON rt.sample_number = t.parent_sample
       )

       SELECT sample_number
       FROM recursetree;
$BODY$
 LANGUAGE sql VOLATILE

CREATE OR REPLACE FUNCTION fn_get_subsamples(IN sample_numbers integer[])
RETURNS SETOF integer AS
$BODY$
WITH RECURSIVE recursetree(sample_number) AS (
SELECT sample_number
FROM sample
WHERE parent_sample in (select unnest($1))

UNION ALL

SELECT t.sample_number
FROM sample t
JOIN recursetree rt ON rt.sample_number = t.parent_sample
)

SELECT sample_number
FROM recursetree;
$BODY$
LANGUAGE sql VOLATILE

merlin

thanks a lot!
that function does it exactly as wished ;)!

Am 23.03.2011 22:46, schrieb Merlin Moncure: