<?
$dbconnection;
$table=”members”;
$csv = NULL;
/* link identifier from db connection */
$r = mysql_query(“SHOW COLUMNS FROM “.$table);
while ($row = mysql_fetch_assoc($r)) {
$csv .= $row['Field'].’,';
}
$csv = substr($csv, 0, -1).”n”;
$r = mysql_query(“SELECT * FROM “.$table);
while ($row = mysql_fetch_assoc($r)) {
$csv .= ‘”‘.join(‘”,”‘, str_replace(‘”‘, ‘”"‘, $row)).”"n”;
}
header(“Content-type: application/vnd.ms-excel”);
header(“Content-disposition: csv; filename=” . date(“Y-m-d”) .”_”.$table.”.csv; size=”.strlen($csv));
echo $csv;
exit;
?>

Very nice.
I also wrote something similar, but works for Muti-dimentional arrays instead of database results.
Create CSV Files From Multi-dimentional arrays in PHP