How to create a downloadable Excel sheet from a database using PHP and MySQL.

Using PHP and MySQL to create a downloadable Excel sheet from a database entails first retrieving data from the database, preparing it for Excel, and then sending the relevant HTTP headers to initiate a download.

// Please acknowledge use of this code by including this header.

  $data = array(
    array("firstname" => "Mary", "lastname" => "Johnson", "age" => 25),
    array("firstname" => "Amanda", "lastname" => "Miller", "age" => 18),
    array("firstname" => "James", "lastname" => "Brown", "age" => 31),
    array("firstname" => "Patricia", "lastname" => "Williams", "age" => 7),
    array("firstname" => "Michael", "lastname" => "Davis", "age" => 43),
    array("firstname" => "Sarah", "lastname" => "Miller", "age" => 24),
    array("firstname" => "Patrick", "lastname" => "Miller", "age" => 27)
  );

 function cleanData(&$str)
  {
    if($str == 't') $str = 'TRUE';
    if($str == 'f') $str = 'FALSE';
    if(preg_match("/^0/", $str) || preg_match("/^\+?\d{8,}$/", $str) || preg_match("/^\d{4}.\d{1,2}.\d{1,2}/", $str)) {
      $str = "'$str";
    }
    if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
  }

  // filename for download function

  $filename = "website_data_" . date('Ymd') . ".xls";

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

  $out = fopen("php://output", 'w');

  $flag = false;
  foreach($data as $row) {
    if(!$flag) {
      // display field/column names as first row
      fputcsv($out, array_keys($row), ',', '"');
      $flag = true;
    }
    array_walk($row, __NAMESPACE__ . '\cleanData');
    fputcsv($out, array_values($row), ',', '"');
  }

  fclose($out);
  exit;