CREATE OR REPLACE FUNCTION core.is_supplier(bigint)
RETURNS boolean
LANGUAGE plpgsql
AS $function$
BEGIN
IF EXISTS
(
SELECT 1 FROM core.parties
INNER JOIN core.party_types
ON core.parties.party_type_id=core.party_types.party_type_id
WHERE core.parties.party_id=$1
AND core.party_types.is_supplier=true
) THEN
RETURN true;
END IF;
RETURN false;
END
$function$