php导出CSV

<?php
//导出的首行标题以及需要导出的字段
$parm = array(
     "公司名称"=>'business_name',
     '公司城市'=>'province',
     '公司地址'=>'detail_addr_'
 );

/**
* 导出CSV文件
* @param array $data        数据
* @param array $header_data 首行数据
* @param string $file_name  文件名称
* @param string $body_data  需要导出的字段名
* @return string
*/
public function export_csv($data = [], $parm = [], $file_name = '')
{
  header('Content-Type: application/vnd.ms-excel');
  header('Content-Disposition: attachment;filename='.$file_name);
  header('Cache-Control: max-age=0');
  $fp = fopen('php://output', 'a');
  $header_data = array_keys($parm);
  $body_data = array_values($parm);

  if (!empty($header_data)) {
   foreach ($header_data as $key => $value) {
       $header_data[$key] = iconv('utf-8', 'gbk', $value);
   }
   fputcsv($fp, $header_data);
  }
  $num = 0;
  $limit = 100000;
  //逐行取出数据，不浪费内存
  $count = count($data);
  if ($count > 0) {
   for ($i = 0; $i < $count; $i++) {
       $num++;
       //刷新一下输出buffer，防止由于数据过多造成问题
       if ($limit == $num) {
           ob_flush();
           flush();
           $num = 0;
       }
       $row = [];
       $export_data = $data[$i];
       foreach ($export_data as $key => $value) {
           if(!in_array($key,$body_data)){
               continue;
           }else{
               foreach($body_data as $key1=>$value1){
                   $row[$value1] = iconv('utf-8', 'gbk', $export_data[$value1]);
               }

           }
       }
       fputcsv($fp, $row);
   }
  }
  fclose($fp);
}


public function export_csv_1($data = [], $header_data = [], $file_name = '')
{
  header('Content-Type: application/octet-stream');
  header('Content-Disposition: attachment; filename=' . $file_name);
  if (!empty($header_data)) {
   echo iconv('utf-8','gbk//TRANSLIT','"'.implode('","',$header_data).'"'."\n");
  }
  foreach ($data as $key => $value) {
   $output = array();
   $output[] = $value['id'];
   $output[] = $value['name'];
   echo iconv('utf-8','gbk//TRANSLIT','"'.implode('","', $output)."\"\n");
  }
}