Adodb using php with PostgreSQL - ADODB ASSOC_CASE not working

Question

Trying below code

*require "./adodb.inc.php";
define('ADODB_ASSOC_CASE', ADODB_ASSOC_CASE_UPPER);
$ADODB_FETCH_MODE = ADODB_FETCH_ASSOC;
 
$db = ADONewConnection('postgres');
$db->connect($host, $user, $password, $database);*

able to connect to database but ADODB_ASSOC_CASE is setting to 2 as NATIVE instead of 1 i.e UPPER

is there any way to force set the value of ADODB_ASSOC_CASE to UPPER