sql - Export large data to CSV using PHP -

i trying export data csv using php.

my code:

function download_send_headers($filename) {     // disable caching     $now = gmdate("d, d m y h:i:s");     header("expires: tue, 03 jul 2001 06:00:00 gmt");     header("cache-control: max-age=0, no-cache, must-revalidate, proxy-revalidate");     header("last-modified: {$now} gmt");      // force download       header("content-type: application/force-download");     header("content-type: application/octet-stream");     header("content-type: application/download");      // disposition / encoding on response body     header("content-disposition: attachment;filename={$filename}");     header("content-transfer-encoding: binary"); }  $giventerm = $_post['textboxlist'];  $sql_query = "select * some_table key=".$giventerm; $result = sqlsrv_query($conn,$sql_query); $r1 = array(); $file = fopen("php://output", 'w'); while ($row = sqlsrv_fetch_array($result, sqlsrv_fetch_numeric)){     $valuesarray=array();     foreach($row $name => $value)     {         $valuesarray[]=$value;     }     fputcsv($file,$valuesarray); } fclose($file); download_send_headers("data_export_" . date("y-m-d") . ".csv");  die(); 

here receiving search-value form in page , triggering query based on it. code working fine smaller data-sets(up 100). when number of rows more in result (around 600-700) code crashes. please tell me how fix this.

p.s. using sql server 2012 database.

instead of first getting results in single array , outputting it, fetch row row , outputting each row directly. way won't need massive amount of memory fit entire array in.