title: Wordpress export data from database to csv using $wpdb
body: <p>I am stuck with this problem, i have a code to insert the data to database, and query it all at the wordpress page. then i want to export it in csv, but i dont know how to do it. i have codes found on internet but not working. i dont know why, please check my codes. this is my codes.. </p>
  
  <pre><code> global $wpdb;
      if(isset($_POST["Export"])){
      $result = $wpdb-&gt;get_results('SELECT * FROM backend_member', ARRAY_A);
  
      header('Content-Type: text/csv');
      $date = date("Y-m-d H:i:s");
      header('Content-Disposition: attachment;filename=EXPORT_' . $date . '.csv');
  
      foreach ($result as $row) {
          if ($row) {
              exportCsv(array_keys($row));
          }}
      while ($row) {
          foreach ($result as $row) {
                  exportCsv($row);
          }}
      function exportCsv($rows) {
          $separator = '';
          foreach ($rows as $row) {
              echo $separator . $row;
              $separator = ',';
          }
          echo "\r\n";
      }
  }
  
  &lt;div&gt;&lt;form class="form-horizontal" action="" enctype="multipart/form-data" method="post" name="upload_excel"&gt;
  &lt;div class="form-group"&gt;
  &lt;div class="col-md-4 col-md-offset-4"&gt;&lt;input class="btn btn-success" name="Export" type="submit" value="export to excel" /&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;/form&gt;&lt;/div&gt;
  </code></pre>
  
  <p>When i click export. i have an error.</p>
  
  <pre><code>This site can’t be reached
  
  The webpage at http://www.rimelig-skat.dk/din-admin/ might be temporarily down or it may have moved permanently to a new web address.
  ERR_INVALID_RESPONSE
  </code></pre>