I think I just found the answer. The select "*" needs to be cleared out first. The following seems to work.
->select(null)->select('[LOCID], [LOCNAME], [LOCSHORT]')
I also need to revise the PDO parameter binding in the where() method. It seems that this library is a bit different than expected (notice 'PDO::FETCH_ASSOC' is not needed). Full working code below:
function getAllCenters() {
global $fpdo, $pdo;
$query = $fpdo->from('z_cc_locs2')
->select(null)->select("[LOCID], [LOCNAME], [LOCSHORT], RIGHT('00'+ CAST([CENTER] as varchar(4)),4) as CENTER, [LAT], [LONG], [LOCATION_ID]")
->where("LOCNAME <> :name", array(':name' => 'Formosa'))
->orderBy("LOCNAME ASC");
$result = $query->fetchAll();
foreach ($result as $row) {
$rows[] = $row;
}
return json_encode($rows);
}