Download from database - php

Question

I'm trying to download a list of email addresses from a database in WordPress to .CSV.
Anybody point me in the right direction:
header("Content-type: text/csv");
header("Content-Disposition: attachment; filename=file.csv");
header("Pragma: no-cache");
header("Expires: 0");
$results = $wpdb->get_results( "SELECT * FROM table");
while ($row = mysql_fetch_array($results, MYSQL_ASSOC)){
$data = json_encode($row);
}
outputCSV($data);
function outputCSV($data) {
$output = fopen("php://output", "w");
foreach ($data as $row) {
fputcsv($output, $row);
}
fclose($output);
}

Answer 1

This will do the trick:
header("Content-type: application/vnd.ms-excel");
header('Content-Disposition: attachment; filename="filename.csv"');
header("Pragma: no-cache");
header("Expires: 0");
echo '"Header 1","Header 2","Header 3"'."\n";
$results = $wpdb->get_results("SELECT * FROM `wp_newsletter_signup`");
while ($row = mysql_fetch_array($results, MYSQL_ASSOC)){
echo '"' . $row['column1'] . '","' . $row['column2'] . '","' . $row['column3'] . '"' . "\n";
}
die();
Note my content type of application/vnd.ms-excel I use this as personal preference due to higher support in older windows machines, but you can continue to use text/csv - A list of mime types can be found here http://filext.com/file-extension/CSV

Answer 2

Change
while ($row = mysql_fetch_array($results, MYSQL_ASSOC)){
$data = json_encode($row);
}
to
while ($row = mysql_fetch_array($results, MYSQL_ASSOC)){
$data[] = $row;
}