先说说动态生成的内容当作文件来下载的方法:

1、通过把Content-Type设置为application/octet-stream,可以把动态生成的内容当作文件来下载;content-type内容设置可以参看:

http://www.ostools.net/commons

2、用Content-Disposition设置下载的文件名;

3、 基本上,下载程序都是这么写的:

<?php  
$filename = "document.txt";  
header('Content-Type: application/octet-stream');  
header('Content-Disposition: attachment; filename=' . $filename);  
print "Hello!";  
?>

4、当然要考虑到浏览器兼容性和对如果文件名是中文的话出现异常bug,我们这么写:

<?php  
$ua = $_SERVER["HTTP_USER_AGENT"];  
$filename = "文件名.txt";  
$encoded_filename = urlencode($filename);  
$encoded_filename = str_replace("+", "%20", $encoded_filename);  
header('Content-Type: application/octet-stream');  
if (preg_match("/MSIE/", $ua)) {  
   header('Content-Disposition: attachment; filename="' . $encoded_filename . '"');  
} else if (preg_match("/Firefox/", $ua)) {  
   header('Content-Disposition: attachment; filename*="utf8\'\'' . $filename . '"');  
} else {  
   header('Content-Disposition: attachment; filename="' . $filename . '"');  
}  
print 'ABC';  
?>

明白了这些之后,生成excel就很简单了,处理下下载文档格式,解析数据,balabala就好了,看看怎么生成一篇excel的文档吧:

1、原始方式:发送header,用附件的表头发送到用户浏览器表示是要下载的,然后读出数据库中的数据,一条一条的解析,写入excel格式的文件中。

<?php  
 $DB_Server = "localhost";  
 $DB_Username = "root";  
 $DB_Password = "";  
 $DB_DBName = "DBName";  
 $DB_TBLName = "DB_TBLName";  
 $savename = date("YmjHis");  
 $Connect = @mysql_connect($DB_Server, $DB_Username, $DB_Password) or die("Couldn't connect.");  
 mysql_query("Set Names 'gbk'");  
 $file_type = "vnd.ms-excel";  
 $file_ending = "xls";  
 header("Content-Type: application/$file_type;charset=gbk");  
 header("Content-Disposition: attachment; filename=".$savename.".$file_ending");  
 header("Pragma: no-cache");  
 $now_date = date("Y-m-j H:i:s");  
 $title = "数据库名:$DB_DBName,数据表:$DB_TBLName,备份日期:$now_date";  
 $sql = "Select * from $DB_TBLName";  
 $ALT_Db = @mysql_select_db($DB_DBName, $Connect) or die("Couldn't select  database");  
 $result = @mysql_query($sql,$Connect) or die(mysql_error());  
 echo("$title\n");  
 $sep = "\t";  
 for ($i = 0;$i < mysql_num_fields($result);$i++)  
    {  
        echo mysql_field_name($result,$i) . "\t";  
    }  
 print("\n");  
 $i = 0;  
 while($row = mysql_fetch_row($result))  
 {  
   $schema_insert = "";  
   for($j=0; $j<mysql_num_fields($result);$j++)  
     {  
       if(!isset($row[$j])) $schema_insert .= "NULL".$sep;  
       elseif ($row[$j] != "") $schema_insert .= "$row[$j]".$sep;  
       else $schema_insert .= "".$sep;  
      }  
      $schema_insert = str_replace($sep."$", "", $schema_insert);  
      $schema_insert .= "\t";  
      print(trim($schema_insert));  
      print "\n"; $i++;  
 }  
 return (true);  
 ?>

2、用PHPExcel库

下面是用PHPExcel实现的与上面功能相同的excel的方法。getCol为递归实现的函数,用于根据数字返回对应的列号编码。因为导出的过程中需要指出行号,列号。行号为简单的数字,而列号则为“A-Z”的组合。为了方便二维数组的导入,根据列数自动得到列号编码。如“5”->“E”、“27”->“AZ”。

//设置PHPExcel类库的include path  
$dirToLib1='./resource/PHPExcel1.7.0/Classes';  
ini_set('include_path', ini_get('include_path').PATH_SEPARATOR.$dirToLib1);  
  
function getCol($num){//递归方式实现根据列数返回列的字母标识  
        $arr=array(0=>'Z',1=>'A',2=>'B',3=>'C',4=>'D',5=>'E',6=>'F',7=>'G',8=>'H',9=>'I',10=>'J',11=>'K',12=>'L',13=>'M',14=>'N',15=>'O',16=>'P',17=>'Q',18=>'R',19=>'S',20=>'T',21=>'U',22=>'V',23=>'W',24=>'X',25=>'Y',26=>'Z');  
        if($num==0)  
        return '';  
        return $this->getCol((int)(($num-1)/26)).$arr[$num%26];  
    }   
function exportToExcel($header,$data,$fileName){
//利用PHPExcel工具进行导出,功能强大,格式规范,可导出2007  
        $fileName=$this->UTF8ToGBK($fileName);    
        $objExcel = new PHPExcel();  
        $objWriter = new PHPExcel_Writer_Excel5($objExcel);  
        $objExcel->setActiveSheetIndex(0);  
        $objActSheet = $objExcel->getActiveSheet();  
        //设置当前活动sheet的名称  
        //$objActSheet->setTitle('测试Sheet');   
        //*************************************  
        //设置单元格内容  
        $i=1;  
        foreach ($header as $key => $value){  
            $objActSheet->setCellValueExplicit($this->getCol($i).'1', $value,PHPExcel_Cell_DataType::TYPE_STRING);  
            //*************************************  
            //设置单元格样式  
            $objStyle = $objActSheet->getStyle($this->getCol($i++).'1');  
            //设置边框  
            $objBorder = $objStyle->getBorders();  
    	    $objBorder->getTop()->setBorderStyle(PHPExcel_Style_Border::BORDER_THIN);  
            $objBorder->getTop()->getColor()->setARGB('FFDDDDDD');                          
            $objBorder->getBottom()->setBorderStyle(PHPExcel_Style_Border::BORDER_THIN);  
            $objBorder->getBottom()->getColor()->setARGB('FFDDDDDD');  
            $objBorder->getLeft()->setBorderStyle(PHPExcel_Style_Border::BORDER_THIN);  
            $objBorder->getLeft()->getColor()->setARGB('FFDDDDDD'); // color  
             $objBorder->getRight()->setBorderStyle(PHPExcel_Style_Border::BORDER_THIN);  
            $objBorder->getRight()->getColor()->setARGB('FFDDDDDD'); // color  
            //设置填充颜色  
            $objFill = $objStyle->getFill();  
            $objFill->setFillType(PHPExcel_Style_Fill::FILL_SOLID);  
            $objFill->getStartColor()->setARGB('FF00EEEE');  
        }  
        $i=1;  
        foreach ($data as $row){  
            $i++;  
            $j=1;  
            foreach ($header as $key => $value){  
                $objActSheet->setCellValueExplicit($this->getCol($j++).$i, $row[$key],PHPExcel_Cell_DataType::TYPE_STRING);  
            }  
        }  
        //*************************************  
        //输出内容  
        //到浏览器  
        header("Content-Type: application/force-download");  
        header("Content-Type: application/octet-stream");  
        header("Content-Type: application/download");  
        header('Content-Disposition:inline;filename="'.$fileName.'.xls"');  
        header("Content-Transfer-Encoding: binary");  
        header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");  
        header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");  
        header("Cache-Control: must-revalidate, post-check=0, pre-check=0");  
        header("Pragma: no-cache");  
        $objWriter->save('php://output');  
    }

3、用PHPExcel等库,确实比较容易实现,但对大量数据的支持很不好,很容易到达PHP内存使用上限。这里的方法是利用fputcsv写CSV(这是一种逗号分隔值文件格式,见http://baike.baidu.com/view/468993.htm)文件的方法,直接向浏览器输出Excel文件:

<?php  
// 输出Excel文件头,可把user.csv换成你要的文件名  
header('Content-Type: application/vnd.ms-excel');  
header('Content-Disposition: attachment;filename="user.csv"');  
header('Cache-Control: max-age=0');     
// 从数据库中获取数据,为了节省内存,不要把数据一次性读到内存,从句柄中一行一行读即可  
$sql = 'select * from tbl where ……';  
$stmt = $db->query($sql);     
// 打开PHP文件句柄,php://output 表示直接输出到浏览器  
$fp = fopen('php://output', 'a');    
// 输出Excel列名信息  
$head = array('姓名', '性别', '年龄', 'Email', '电话', '……');  
foreach ($head as $i => $v) {  
    // CSV的Excel支持GBK编码,一定要转换,否则乱码  
    $head[$i] = iconv('utf-8', 'gbk', $v);  
}    
// 将数据通过fputcsv写到文件句柄  
fputcsv($fp, $head);   
// 计数器  
$cnt = 0;  
// 每隔$limit行,刷新一下输出buffer,不要太大,也不要太小  
$limit = 100000;    
// 逐行取出数据,不浪费内存  
while ($row = $stmt->fetch(Zend_Db::FETCH_NUM)) {   
    $cnt ++;  
    if ($limit == $cnt) { 
        //刷新一下输出buffer,防止由于数据过多造成问题  
        ob_flush();  
        flush();  
        $cnt = 0;  
    }  
   
    foreach ($row as $i => $v) {  
        $row[$i] = iconv('utf-8', 'gbk', $v);  
    }  
    fputcsv($fp, $row);  
}