create and download a csv file from php script

download_csv_file_from_php

$con = mysqli_connect("localhost","my_user","my_password","my_db");
$query = "select * from user table";
$result = mysqli_query($con,$query);
 $array_key = ((array) $result[0]);
        $headers = (object) array_keys($array_key);
        $delimiter = ",";
        $filename = 'process.csv';
        $f = fopen('php://memory', 'w');
        fputcsv($f, (array)$headers, $delimiter);
        foreach ($result as $line) {
            $phpar = (array) $line;
            fputcsv($f, $phpar, $delimiter);
        }
        fseek($f, 0);
        header('Content-Type: application/csv');
        header('Content-Disposition: attachment; filename="' . $filename . '";');
        fpassthru($f);