编写自己的CSV代码可能是浪费你的时间，只是使用一个包，如league/ CSV -它为你处理所有困难的事情，文档是很好的，它是非常稳定/可靠的:

http://csv.thephpleague.com/

你需要使用作曲家。如果你不知道什么是作曲家，我强烈建议你去看看:https://getcomposer.org/

下面是一个使用PDO并包含列标题的完整工作示例:

$query = $pdo->prepare('SELECT * FROM test WHERE id=?');
$query->execute(array($id));    
$results = $query->fetchAll(PDO::FETCH_ASSOC);
download_csv_results($results, 'test.csv'); 
exit();


function download_csv_results($results, $name)
{            
    header('Content-Type: text/csv');
    header('Content-Disposition: attachment; filename='. $name);
    header('Pragma: no-cache');
    header("Expires: 0");

    $outstream = fopen("php://output", "wb");    
    fputcsv($outstream, array_keys($results[0]));

    foreach($results as $result)
    {
        fputcsv($outstream, $result);
    }

    fclose($outstream);
}

header("Content-Type: text/csv");
header("Content-Disposition: attachment; filename=file.csv");

function outputCSV($data) {
  $output = fopen("php://output", "wb");
  foreach ($data as $row)
    fputcsv($output, $row); // here you can change delimiter/enclosure
  fclose($output);
}

outputCSV(array(
  array("name 1", "age 1", "city 1"),
  array("name 2", "age 2", "city 2"),
  array("name 3", "age 3", "city 3")
));

php: / /输出 函数

要让它以CSV格式发送，并给出文件名，请使用header():

http://us2.php.net/header

header('Content-type: text/csv');
header('Content-disposition: attachment; filename="myfile.csv"');

至于创建CSV本身，您只需要遍历结果集，格式化输出并发送它，就像处理任何其他内容一样。

您可以使用fputcsv函数简单地将数据写入CSV。让我们看看下面的例子。将列表数组写入CSV文件

$list[] = array("Cars", "Planes", "Ships");
$list[] = array("Car's2", "Planes2", "Ships2");
//define headers for CSV 
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename=file_name.csv');
//write data into CSV
$fp = fopen('php://output', 'wb');
//convert data to UTF-8 
fprintf($fp, chr(0xEF).chr(0xBB).chr(0xBF));
foreach ($list as $line) {
    fputcsv($fp, $line);
}
fclose($fp);

嘿它工作得很好....!!!!谢谢Peter Mortensen和Connor Burton

<?php
header("Content-type: application/csv");
header("Content-Disposition: attachment; filename=file.csv");
header("Pragma: no-cache");
header("Expires: 0");

ini_set('display_errors',1);
$private=1;
error_reporting(E_ALL ^ E_NOTICE);

mysql_connect("localhost", "user", "pass") or die(mysql_error());
mysql_select_db("db") or die(mysql_error());

$start = $_GET["start"];
$end = $_GET["end"];

$query = "SELECT * FROM customers WHERE created>='{$start} 00:00:00'  AND created<='{$end} 23:59:59'   ORDER BY id";
$select_c = mysql_query($query) or die(mysql_error());

while ($row = mysql_fetch_array($select_c, MYSQL_ASSOC))
{
    $result.="{$row['email']},";
    $result.="\n";
    echo $result;
}

?>