Save query results to .csv with PHP - php

Question

I have the following query running and I am looking at the best way to export the data to a .csv or .xls file.
<?php
$channels = ee()->db->select('channel_titles.entry_id, channel_titles.title, channel_data.field_id_164')
->from('channel_titles')
->join('channel_data', 'channel_titles.entry_id = channel_data.entry_id')
->where(array(
'channel_titles.channel_id' => '12',
))
->or_where(array(
'channel_titles.channel_id' => '31',
))
->get();
if ($channels->num_rows() > 0)
{
$i = 0;
foreach($channels->result_array() as $row)
{
$i++;
echo $row['field_id_164'].",".$row['title']."<br />\n";
}
echo $i;
}
?>
I have tried a few methods but cannot seem to figure out the best option.

Answer 1

The classic echo explode(',',$col) etc way is fine, but you can also write directly to the csv file using php's built in functions.
$filename = 'test.csv';
$file = fopen($filename,"w");
if ($channels->num_rows() > 0) {
foreach($channels->result_array() as $key => $row) {
if ($key==0) fputcsv($file, array_keys((array)$row)); // write column headings, added extra brace
foreach ($row as $line) {
$line = (array) $line;
fputcsv($file, $line);
}
}
}
fclose($file);
edit:
If you want to download/view the file instantly you have to set the headers.
$filename = 'test.csv';
header('Content-type: application/csv');
header('Content-Disposition: attachment; filename=' . $filename);
header("Content-Transfer-Encoding: UTF-8");
$file = fopen('php://output', 'a');
if ($channels->num_rows() > 0) {
foreach($channels->result_array() as $key => $row) {
if ($key==0) fputcsv($file, array_keys((array)$row)); // write column headings, added extra brace
foreach ($row as $line) {
$line = (array) $line;
fputcsv($file, $line);
}
}
}
fclose($file);