Exporting CSV | Weird Behaviour - php

Question

So, I think that I have asked this question and others related to it for more than twice. But I cannot figure out what's happening.
I'm using this PHP function to export some data from a table to a CSV table. I am testing on local host ( XAAMP ):
// Export CSV By User Level
public function CSVData($path, $level) {
switch ($level) {
case 0:
$filename = $path."/standard_members_".date('Y')."_".date('m')."_".date('d').".csv";
break;
case 1:
$filename = $path."/special_members_".date('Y')."_".date('m')."_".date('d').".csv";
break;
case 2:
$filename = $path."/admin_members_".date('Y')."_".date('m')."_".date('d').".csv";
break;
default:
break;
}
$sql = "SELECT user_name, user_username, user_email, user_register_date INTO OUTFILE '$filename' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '\"' LINES TERMINATED BY '\n' FROM users WHERE user_level = '$level'";
if ($stmt = $this->connect->prepare($sql)) {
if(!($stmt->execute())){
print_r($stmt->error);
}
$stmt->close();
} else {
$error = true;
$message['error'] = true;
$message['message'] = CANNOT_PREPARE_DATABASE_CONNECTION_MESSAGE;
return json_encode($message);
}
if(!is_file($filename)) {
die('file not found');
} else {
header('Content-Type: application/csv');
header("Content-Disposition: attachment; filename=$filename");
header('Expires: 0');
header('Pragma: no-cache');
readfile($filename);
}
}
And I have a form that performs the action, I mean it submits the action to the PHP file which processes the above function, and this is the action code:
<?php
include '../assets/class/login/loginsys.php';
$extension = new extension;
if ($_GET['action'] == 0) {
$extension->CSVData('exports', 0);
} elseif ($_GET['action'] == 1) {
$extension->CSVData('exports', 1);
} elseif ($_GET['action'] == 2) {
$extension->CSVData('exports', 2);
}
exit();
?>
What happens is the following:
-when I click the submit button on the form I have it sends either the value 0, 1 or 2 to the action code;
-the action code gets the value and processes accordingly;
-but if I haven't created the folder 'exports' on localhost if would have given me this error:
Can't create/write to file 'C:xampphtdocsloginadminexports\standard_members_2012_01_28.csv' (Errcode: 2);
-and I have created it so it can work;
-now that the folder it's there the CSV file is created and the data is dumped into the CSV table;
-but the file that opens in my browser ( the attachment that downloads like you'd click on a file from some website and downloaded it ) it's empty even though the file exported in 'exports' has the data in it;
-and another thing is that when the file already exists in the folder 'exports' the table that is created is tells me:
File 'exports/admin_members_2012_01_29.csv' already exists
So my question is why is what I described happening ? And is there a way to make the MySql query overwrite the previous CSV file ?

Answer 1

You don't need that temporary file. How about this:
define('CSV_SEPARATOR', ',');
// CSV download headers
header('Content-Type: text/csv; charset=UTF-8');
header('Content-Disposition: attachment; filename="my.csv"');
// A file handle to PHP output stream
$fp = fopen('php://output', 'w');
// UTF-8 BOM
echo "\xEF\xBB\xBF";
// Get data from database
$data = ...;
// List of columns
$columns = array(
'User name',
'First name',
'Last name'
);
foreach ($data as $key => $row) {
// Write columns
if ($key == 0) {
fputcsv($fp, $columns, CSV_SEPARATOR);
}
// Write data
fputcsv($fp, $row, CSV_SEPARATOR);
}
fclose($fp);
Beautiful, isn't it?