PHP about problems such as memory overflow timeout caused by large amount of data exporting or traversing data

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php With regard to the large amount of data, exporting data or traversing data leads to memory overflow timeout and other problems

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Don't talk much, just go to the code

$p = 0;$pageSize=100; //  Define the number of display bars per page 

  set_time_limit(0);// This is a fairy function. It's great , Its main function is to  : Set the maximum execution time of the script , The unit is in seconds . If set to 0（ zero ）, There is no time limit .
   while (

        $list = db('user')->order('a.id desc')->limit($p*$pageSize, $pageSize)->select()// Get data per page , To separate 
        ) {
    
            foreach ($list as $k=>$v) {
    
              //  The following content is the exported list content copy can be omitted 
                $index = $k + $p * $pageSize + 3;
                // switch ($v['type']) {
    
                // case 1:
                // $lx = ' Online order ';
                // break;
                // case 2:
                // $lx = ' Offline order ';
                // break;
                // default:
                // $lx = '';
                // }
                // $address = json_decode($v['address'], true);
       
                $objPHPExcel->getActiveSheet()
                    ->setCellValue('A'.$index, $v['uname'])
                    ->setCellValue('B'.$index, $v['bid'].' ')
                    ->setCellValue('C'.$index, $v['pid'].' ')
                    ->setCellValue('D'.$index,  $v['amount'].' ')
                    ->setCellValue('E'.$index, $v['f_amount'].' ')
                    ->setCellValue('F'.$index,  $v['open_bank'])
                    ->setCellValue('G'.$index,  ' '.$v['card_number'].' ')
                    ->setCellValue('H'.$index,  $v['jg_name'].' ')
                    ->setCellValue('I'.$index, ' '.$v['jg_number'].'')
                    ->setCellValue('J'.$index, ' '.$v['id_card_code'].'');

                $objPHPExcel->getActiveSheet()->getRowDimension($index)->setRowHeight(16);
            }
            $p++;// Page number increase 
        }
  

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