我怎么能把一个单一的值在一个单一的列与fputcsv

我想从数据库导出数据到CSV文件。

我的PHP代码是这样的

$members = Db::getResult('select * from '.MEMBERS_TABLE_NAME.' order by '.MEMBERS_COLUMN_PREFIX.'_lastname, '.MEMBERS_COLUMN_PREFIX.'_firstname');
    $fileName = "../db_user_export".".csv";
    $handle = fopen($fileName, 'w+');
    fputcsv($handle, array_keys($members[0]));
    foreach ($members as $member) {
        fputcsv($handle, $member);
    }//foreach
    fclose($handle);

"COLUMN A" "COLUMN B" "COLUMN C"， "password,username，姓，updated" "loggedin,is_new"

但是我想要这样:

"COLUMN A" "COLUMN B" "COLUMN C"， "password" "username" "firstname".

谁知道怎么做?