A php file that takes a WP table and saves as a CSV

wp_export_csv.php

<?php

require_once('../../../../wp-load.php');

global $wpdb;
$wpdb->show_errors();

$table_name = $wpdb->prefix . "arg_signups";
if($wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name) { 
  newsletter_install();
}

$signups = $wpdb->get_results("SELECT * FROM `$table_name` ORDER BY id");


$header = "id\tname\temail\t";
$data = '';
if(!empty($signups)) {
	foreach ($signups as $signup) {
		$line = "\"" . $signup->id . "\"\t";
		$line .= "\"" . $signup->name . "\"\t";
		$line .= "\"" . $signup->email . "\"\t";
		$data .= $line . "\n";
	}
} else {
	$data = "\n(0) Records Found!\n";  
}

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=signups.csv");
header("Pragma: no-cache");
header("Expires: 0");
print "$header\n$data";
exit;