Re: Array intersection

On Wed, 17 Oct 2007 17:42:21 +0100
Sam Mason  wrote:



>   CREATE OR REPLACE FUNCTION array_intersect (array1
> INTEGER[],array2 INTEGER[])  RETURNS INTEGER[] AS $$  
>      DECLARE
>        out INTEGER[];
>      BEGIN
>         out := '{}'::INTEGER[];
>         IF array1 IS NULL OR array2 IS NULL THEN
>           RETURN NULL;
>         END IF;
>         FOR i IN array_lower(array1,1) .. array_upper(array1,1) LOOP
>           IF (array1[i] = ANY (array2)) AND NOT array1[i] = ANY
> (out) THEN out := array_append(out,array1[i]);
>           END IF;
>         END LOOP;
>         RETURN out;
>      END;
>   $$ LANGUAGE PLPGSQL;

Works like a champ on 8.1.

Thanks!

Did you see David Fetter's reply to the original post?  He has
an interesting alternative.

Josh