Re: Array intersection

On Wed, 17 Oct 2007 10:04:21 -0700
David Fetter <david(at)fetter(dot)org> wrote:

<snip>

> CREATE OR REPLACE FUNCTION array_intersect(ANYARRAY, ANYARRAY)
> RETURNS ANYARRAY
> LANGUAGE SQL
> AS $$
> SELECT ARRAY(
> SELECT $1[i] AS "the_intersection"
> FROM generate_series(
> array_lower($1,1),
> array_upper($1,1)
> ) AS i
> INTERSECT
> SELECT $2[j] AS "the_intersection"
> FROM generate_series(
> array_lower($2,1),
> array_upper($2,1)
> ) AS j
> );
> $$;

Doesn't appear to work on 8.1:

psql=> select array_intersect('{1,2,3}', '{2,3,4}');
ERROR: could not determine anyarray/anyelement type because input
has type "unknown"

Hopefully upgrading to 8.3 soon so I'll have another look then.

Thanks,

Josh