php怎么把数据表中的数据导出到excel表中

";
//导出表头（也就是表中拥有的字段）
while ($row = mysql_fetch_array($res)) {
    $t_field[] = $row['Field']; //Field中的F要大写，否则没有结果
    echo "" . $row['Field'] . "";
}
echo "";
//导出100条数据
$sql = "select * from users limit 100";
$res = mysql_query($sql);
while ($row = mysql_fetch_array($res)) {
    echo "";
    foreach ($t_field as $f_key) {
        echo "" . $row[$f_key] . "";
    }
    echo "";
}
echo "";