代码在导出时扩展php中的excel列宽

Question

我是PHP新手并尝试将一些数据库数据导出到Excel文件，如下所示。但在输出中我希望自动调整列宽以查看整个内容。请参阅我用于导出数据的代码。我没有使用任何第三方库进行导出。

<?php    
require_once("db.php");   

$contents="email,time_in,v_id,time_out\n";   

$user_query = mysql_query('SELECT  * FROM table');   

while($row = mysql_fetch_array($user_query))
{
$contents.=$row['email'].",";
$contents.=$row['time_in'].",";

$contents.=$row['v_id'].",";
$contents.=$row['time_out']."\n";
}

// remove html and php tags etc.
$contents = strip_tags($contents); 

//header to make force download the file

header("Content-Disposition: attachment; filename=Report".date('d-m-Y').".xls");
print $contents;


?>

有没有办法格式化输出？