$dbname="dbname";
$username="username";
$password="password";
$connection=odbc_connect($dbname, $username, $password);

$query="SELECT AVDES3 FROM PFDATA.ME01ITEM";
$result=odbc_exec($connection, $query);

while (odbc_fetch_row($result)){
    $AVDES3=odbc_result($result,'AVDES3');
}