Outputting Column titles in CSV Export - php

Question

I have this query that exports to a csv file. It works fine the only thing i can't figure out is i need to export the column titles as well, and have them display as Full Name, UserName, Flag and Reason. Below is the code and it exports all the rows fine but I'm not sure how to export the column titles above the respected rows.
header("Content-type: text/csv");
header("Content-Disposition: attachment; filename=blackflag_bidders.csv");
header("Pragma: no-cache");
header("Expires: 0");
//SQL Query for Data
$sql = "SELECT ui.first_name, ui.last_name, u.username,
if(u.flag=1,'BLK', if(u.flag=2,'NAA','')) flag,
if(u.flag!=0, IFNULL(ui.note,''),'') reason
FROM user u
LEFT JOIN user_info ui ON ui.user_id=u.id
WHERE u.flag!=0;";
//Prepare Query, Bind Parameters, Excute Query
$STH = $sam_db->prepare($sql);
$STH->execute();
//Export to .CSV
$fp = fopen('php://output', 'w');
//fputcsv($fp);
while ($row = $STH->fetch(PDO::FETCH_NUM)) fputcsv($fp,$row);
fclose($fp);

Answer 1

One way would be to fetch the first result by associative, those associative indices are columns anyway. Apply array_keys to get those, then first add the headers, then the first fetched row, then loop the rest.
// first set
$first_row = $STH->fetch(PDO::FETCH_ASSOC);
$headers = array_keys($first_row);
// $headers = array_map('ucfirst', $headers); // optional, capitalize first letter of headers
fputcsv($fp, $headers); // put the headers
fputcsv($fp, array_values($first_row)); // put the first row
while ($row = $STH->fetch(PDO::FETCH_NUM)) {
fputcsv($fp,$row); // push the rest
}
fclose($fp);

Answer 2

The answer to this will depend upon whether you already know the column names or not. It seems like you do (e.g. you are already calling 'Select ui.firstname...')
If you do not, you can get the names by looking at this thread:
What is the Select statement to return the column names in a table
Once you have the names, you simply need to create a single row with the names and add them to file by modifying your code as:
//Export to .CSV
$columnNamesRow = "FirstName, LastName, UserName";
$fp = fopen('php://output', 'w');
fputcsv($fp, $columnNamesRow);
//fputcsv($fp);
while ($row = $STH->fetch(PDO::FETCH_NUM)) fputcsv($fp,$row);
fclose($fp);

Answer 3

You can get a column in CSV by simply displaying your results in Tabular form here in the page using <table> tag of HTML.
$result = "<table>";
while ($row = $STH->fetch(PDO::FETCH_NUM)){
$result .= "<tr><td>$row1</td><td>$row2</td><td>$row3</td></tr>";
}
$result .= "</table>";
fputcsv($fp, $result);
By $row1, $row2, I mean the values you get in your resultset