Using Phpexcel to export data in batches

if(isset($_post[' Export ']) &&$_post[' export '] = = ' Exporting selected data '){    //This is the check box for the selected data    $export _id=$_post[' Choose ']; if($export _id! = ")    {        $str=implode(",",$export _id); $sql= "SELECT *" from the page WHERE ID in ($str)"; $result=Mysqli_query($link,$sql); if($result)        {             while($row=Mysqli_fetch_assoc($result))            {                $page _info[] =$row; }        }            /** Introduction of Phpexcel*/        include(".. /classes/phpexcel.php "); include(".. /classes/phpexcel/writer/excel2007.php "); //Create an Excel file Object        $objPHPExcel=NewPhpexcel (); //Document Information, click on the table right mouse button to view the properties you can see        $objPHPExcel->getproperties ()->setcreator ("Paper Database Center")            ->setlastmodifiedby ("Excel Document")            ->settitle ("Excel Document")            ->setsubject ("Excel Document")            ->setdescription ("Excel Document from Paper Database Center")            ->setkeywords ("Excel OpenXML php")            ->setcategory ("Excel Export result file"); //Add data according to Excel coordinates        $objPHPExcel->setactivesheetindex (0)            ->setcellvalue (' A1 ', ' Serial number '))            ->setcellvalue (' B1 ', ' title ')            ->setcellvalue (' C1 ', ' author '); //Add Table Contents        foreach($page _info  as $k=$v) {            $num=$k+ 2; $objPHPExcel->setactivesheetindex (0)                ->setcellvalue (' A '.$num, ++$k)                ->setcellvalue (' B ').$num,$v[' title '])                ->setcellvalue (' C ').$num,$v[' Author ']); }        //Renaming work Sheet        $objPHPExcel->getactivesheet ()->settitle (' Export data '); //set the first sheet to work sheet        $objPHPExcel->setactivesheetindex (0); //Save the Excel 95 format file, save the path to the current path,//$objWriter = Phpexcel_iofactory::createwriter ($objPHPExcel, ' Excel5 '); $objWriter->save (' Export.xls ');        Ob_end_clean(); Header(' Content-type:application/vnd.ms-excel;charset=utf-8 '); Header(' content-disposition:attachment;filename= ' Export.xls "'); //header (' cache-control:max-age=0 ');        $objWriter= Phpexcel_iofactory::createwriter ($objPHPExcel, ' Excel5 '); $objWriter->save (' Php://output '); }    Else    {        Echo"<script>alert (' No data selected, please re-select! '); History.go ( -1);</script> "; }}   

Using Phpexcel to export data in batches