Loop through and download multiple CSVs from Database in PHP - php

Question

I have the following code which I am using to download a CSV of the data to a file called Out of Area.csv
<?php
// START EXPORT OF LTHT DATA //
exportMysqlToCsv('Out of Area.csv');
// export csv
function exportMysqlToCsv($filename = 'Out of Area.csv')
{
$conn = dbConnection();
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql_query = "SELECT * FROM MDSData WHERE Downloaded IS NULL ORDER BY RegisteredCCG";
// Gets the data from the database
$result = $conn->query($sql_query);
$f = fopen('php://temp', 'wt');
$first = true;
while ($row = $result->fetch_assoc()) {
if ($first) {
fputcsv($f, array_keys($row));
$first = false;
}
fputcsv($f, $row);
} // end while
$sql_query = "UPDATE MDSData SET Downloaded='YES' WHERE Downloaded IS NULL";
// Gets the data from the database
if ($conn->query($sql_query) === TRUE) {
} else {
}
$conn->close();
$size = ftell($f);
rewind($f);
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Length: $size");
// Output to browser with appropriate mime type, you choose ;)
header("Content-type: text/x-csv");
header("Content-type: text/csv");
header("Content-type: application/csv");
header("Content-Disposition: attachment; filename=$filename");
fpassthru($f);
exit;
}
// db connection function
function dbConnection(){
$servername = "servername";
$username = "username";
$password = "password";
$dbname = "databasename";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
return $conn;
}
header('location:csv-upload-mds.php?week='.$SelectedWeek);
?>
However I have a column in my table called 'TownName' and I would like to loop through creating a CSV Named 'Out of Area - The Town Name Here.csv' for example 'Out of Area - Berkshire.csv'
Currently i've got to the stage where I can make it download 1 file with all the data in, however my issue comes when trying to download multiple files. Even if I duplicate the exportMysqlToCsv() call I get an error as this function can only be called once. So I need to put the loop inside an if statement I guess...
My thoughts are something like the following
$sqlquery = "SELECT * FROM MDSData WHERE Downloaded IS NULL GROUP BY REGISTERED CCG"
$result = $conn->query($sql_query);
while ($row = $result->fetch_assoc()) {
// Now I've looped through each CCG for each one I can set the file name and add the data to the file.
$filename = "Out of Area - " . $row["TownName"]. ".csv";
$sql_query = "SELECT * FROM MDSData WHERE Downloaded IS NULL ORDER BY RegisteredCCG";
// Gets the data from the database
$result = $conn->query($sql_query);
$f = fopen('php://temp', 'wt');
$first = true;
while ($row = $result->fetch_assoc()) {
if ($first) {
fputcsv($f, array_keys($row));
$first = false;
}
fputcsv($f, $row);
} // end while of inside loop
} // end while of 1st SQL query
However whilst I belive my idea is solid, I'm struggling to put it all together and looking for a little help.
Thanks