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

On Wed, Mar 23, 2011 at 10:29 AM, Sven Haag <sven-haag(at)gmx(dot)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