PHP - Creating CSV file inserts empty row at the end

Question

I am trying to create a CSV file in my php script. It creates the file but each time it inserts an empty row at the end.

My code is below:

$csv_output .= "Header 0,";
$csv_output .= "Header 1,";
$csv_output .= "Header 2,";
$csv_output .= "Header 3,";
$csv_output .= "Header 4,";
$csv_output .= "\r\n";

// db query...

foreach($rows as $row):

    if($row["value_3"] == 10)
    {
        $x = 'low';
    }
    else if($row["value_3"] == 100)
    {
        $x = 'high';
    }

    $csv_output .= "".$row["value_0"].",";
    $csv_output .= "".$row["value_1"].",";
    $csv_output .= "".$row["value_2"].",";
    $csv_output .= "".$x.",";
    $csv_output .= "Constant Always Value Goes here (not in db),";
    $csv_output .= "\r\n";
endforeach;

$filename = "csv_".date("d-m-Y_H-i",time());
header("Content-type: application/vnd.ms-excel");
header("Content-disposition: csv" . date("Y-m-d") . ".csv");
header( "Content-disposition: filename=".$filename.".csv");
print $csv_output;

No matter what my database query is or how many rows the csv contains there is always an empty row at the end. Is there anything causing this?

Answer 1

You can write the CSV directly to the output like so, and you don't need to format it yourself.

// Send correctly formatted headers
header("Content-type: application/vnd.ms-excel");

// Disposition should be "attachment" followed by optional filename.
header(sprintf('Content-disposition: attachment; filename="csv_%s.csv"', date("d-m-Y_H-i")));

// Open a pointer to the output stream
$fp = fopen('php://output', 'w');

// Build header array
$head = array(
    "Header 0",
    "Header 1",
    "Header 2",
    "Header 3"
);

// Write the header array in default csv row format.
fputcsv($fp, $head);

// db query...

// Loop rows
foreach($rows as $row) {
    // Write the rows in default csv row format
    fputcsv($fp, $row);
}

// Close the output stream
fclose($fp);

An additional benefit is it will use less memory on large downloads, for instance with PDO:

$stmt = $pdo->prepare("SELECT ...");
$stmt->execute();

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    fputcsv($fp, $row);
}

This will output each row to the browser, directly from the database (more or less), will a very low memory footprint.

Answer 2

Apart from other problems highlighted by Mark Baker, you are adding EOL in the loop. Remove the final one by trim

print trim($csv_output);