从MySQL流二进制文件以使用PHP下载

function getfile($blockid){    global $msa_db;    $sql = "select filename, filedata from blocks where blockid = '$blockid'";    $query = mysql_query($sql, $msa_db);    $result['filename'] = mysql_result($query,0,0);    $result['filedata'] = mysql_result($query,0,1);    return $result;}function download($fileinfo){    $file = base64_depre($fileinfo['filedata']);    header("Cache-Control: no-cache private");    header("Content-Description: File Transfer");    header('Content-disposition: attachment; filename='.$fileinfo['filename']);    header("Content-Type: application/vnd.ms-excel");    header("Content-Transfer-Encoding: binary");    header('Content-Length: '. strlen($file));    echo $file;    exit;}$fileinfo = getfile($blockid);download($fileinfo);