Re: Array intersection

On Wed, 17 Oct 2007 11:26:05 -0700
David Fetter <david(at)fetter(dot)org> wrote:

> > 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"
>
> As mentioned in the "release notes" ;), it's up to you to ensure
> that the arrays have the right types, so you'd write the above as:
>
> SELECT array_intersect('{1,2,3}'::int[], '{2,3,4}'::int[]);

Ah - I saw that but I figured that just meant you couldn't do
something like this:

SELECT array_intersect('{1,2,3}', '{"a","b","c"}');

So basically with this array intersect function you always need to
cast the inputs.

Josh