PHP implements the import and export functions of CSV format data

CREATE TABLE `student` ( 
 `id` int(11) NOT NULL auto_increment, 
 `name` varchar(50) NOT NULL, 
 `sex` varchar(10) NOT NULL, 
 `age` smallint(3) NOT NULL default '0', 
 PRIMARY KEY (`id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

<form id="addform" action="do.php?action=import" method="post" enctype="multipart/form-data"> 
 <p>请选择要导入的CSV文件：<br/><input type="file" name="file"> <input type="submit" 
 class="btn" value="导入CSV"> 
 <input type="button" class="btn" value="导出CSV" onclick="window.location.href=&#39;do.php? 
 action=export&#39;"></p> 
</form>

include_once ("connect.php"); //连接数据库 
$action = $_GET['action']; 
if ($action == 'import') //导入CSV 
{ 
 //导入处理 
}elseif($action=='export') //导出CSV 
{ 
 //导出处理 
}

if ($action == 'import') { //导入CSV 
 $filename = $_FILES['file']['tmp_name']; 
 if(emptyempty ($filename)) 
 { 
  echo '请选择要导入的CSV文件！'; 
  exit; 
 } 
 $handle = fopen($filename, 'r'); 
 $result = input_csv($handle); //解析csv 
 $len_result = count($result); 
 if($len_result==0) 
 { 
  echo '没有任何数据！'; 
  exit; 
 } 
 for($i = 1; $i < $len_result; $i++) //循环获取各字段值 
 { 
  $name = iconv(&#39;gb2312&#39;, &#39;utf-8&#39;, $result[$i][0]); //中文转码 
  $sex = iconv(&#39;gb2312&#39;, &#39;utf-8&#39;, $result[$i][1]); 
  $age = $result[$i][2]; 
  $data_values .= "(&#39;$name&#39;,&#39;$sex&#39;,&#39;$age&#39;),"; 
 } 
 $data_values = substr($data_values,0,-1); //去掉最后一个逗号 
 fclose($handle); //关闭指针 
 $query = mysql_query("insert into student (name,sex,age) values $data_values"); //批量插入数据表中 
 if($query) 
 { 
  echo &#39;导入成功！&#39;; 
 }else{ 
  echo &#39;导入失败！&#39;; 
 } 
}

function input_csv($handle) 
{ 
 $out = array (); 
 $n = 0; 
 while ($data = fgetcsv($handle, 10000)) 
 { 
  $num = count($data); 
  for ($i = 0; $i < $num; $i++) 
  { 
   $out[$n][$i] = $data[$i]; 
  } 
  $n++; 
 } 
 return $out; 
}

... 
}elseif ($action=='export') //导出CSV 
{ 
 $result = mysql_query("select * from student order by id asc"); 
 $str = "姓名,性别,年龄\n"; 
 $str = iconv('utf-8','gb2312',$str); 
 while($row=mysql_fetch_array($result)) 
 { 
  $name = iconv('utf-8','gb2312',$row['name']); //中文转码 
  $sex = iconv('utf-8','gb2312',$row['sex']); 
  $str .= $name.",".$sex.",".$row['age']."\n"; //用引文逗号分开 
 } 
 $filename = date('Ymd').'.csv'; //设置文件名 
 export_csv($filename,$str); //导出 
}

function export_csv($filename,$data) 
{ 
 header("Content-type:text/csv"); 
 header("Content-Disposition:attachment;filename=".$filename); 
 header('Cache-Control:must-revalidate,post-check=0,pre-check=0'); 
 header('Expires:0'); 
 header('Pragma:public'); 
 echo $data; 
}