Generating a CSV download using PDO queries - php

Question

I am trying to make a user able to download a CSV backup of all of their data on my server.
This means i am trying to execute multiple query's and placing the results into a CSV file.
This is what i have so far:
<?php
// Connect
include 'config.php'; // Config contains PDO database connection, etc.
// Generate filename
$filename = $_SESSION['current_group'].'-'.date('d.m.Y').'.csv';
// Get backup data from MYSQL database
$result_users = $conn->prepare('SELECT `user_name`, `user_email` FROM `users` WHERE `group_id` = ?');
$result_users->execute(array($_SESSION['current_group_id']));
$result_items = $conn->prepare('SELECT `item_name`, `item_value`, `item_group` FROM `items` WHERE `group_id` = ?');
$result_items->execute(array($_SESSION['current_group_id']));
# Create array
$list = array ("## START OF USER TABLE ##");
// Append results to array
while ($row = $result_users->fetch(PDO::FETCH_ASSOC)) {
array_push($list, array_values($row));
}
array_push($list,"## END OF USER TABLE ##");
array_push($list,"## START OF ITEMS TABLE ##");
while ($row = $result_items->fetch(PDO::FETCH_ASSOC)) {
array_push($list, array_values($row));
}
array_push($list,"## END OF ITEMS TABLE ##");
// Output array into CSV file
$fp = fopen('php://output', 'w');
header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="'.$filename.'"');
foreach ($list as $ferow) {
fputcsv($fp, split(',',$ferow));
}
?>
The expected output is supposed to be something like:
## START OF USERS TABLE ##
"John","john#email.com"
"James","james#email.com"
## END OF USERS TABLE ##
## START OF ITEMS TABLE ##
"Soap","A lot","Household"
"Banana","2","Food"
## END OF ITEMS TABLE ##
etc.
The problem is that the valued do not correctly get pushed into the $list array.
What should i do in order to get the wanted result?
Thanks!

Answer 1

I think that your code its a little complicated for what you need. I don't test this code but probably works
$sql = "SELECT user_name, user_email FROM users WHERE group_id = :group_id
UNION
SELECT item_name, item_value, item_group FROM items WHERE group_id = :group_id
";
$sth = $conn->prepare($sql);
$sth->bindValue(':group_id', $_SESSION['current_group_id'], PDO::PARAM_INT);
$sth->execute();
$filename = $_SESSION['current_group'].'-'.date('d.m.Y').'.csv';
$data = fopen($filename, 'w');
while ($row = $sth->fetch(PDO::FETCH_ASSOC)) {
fputcsv($data, $row);
}
fclose($data);

Answer 2

I solved it by doing the following:
// Create array
$list = array ();
// Append results to array
array_push($list, array("## START OF USER TABLE ##"));
while ($row = $result_users->fetch(PDO::FETCH_ASSOC)) {
array_push($list, array_values($row));
}
array_push($list, array("## END OF USER TABLE ##"));
// Output array into CSV file
$fp = fopen('php://output', 'w');
header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="'.$filename.'"');
foreach ($list as $ferow) {
fputcsv($fp, $ferow);
}