PHP -不回显来自MySQL数据库的数据，但没有错误

Question

PHP代码:

• 注意:我确实使用了mysqli_connect()。

  $result = mysqli_query($con,"SELECT * FROM `smf_messages` WHERE `id_board` = 18");
  if(!$result) {
      echo "<center><p>Couldn't fetch news posts. Error code 2.</p></center>";
      mysqli_close($con);
  } else {
      $posts = array();
      $topicbdy = array();
      while($row = mysqli_fetch_array($result,MYSQLI_ASSOC))
      {
          $posts[$row['id_topic']] = $row['id_topic'];
          $topicbdy[$row['id_msg']] = $row['id_msg'];
      }
      $display = max($posts);
      $display2 = min($topicbdy);
      $qry = "SELECT * FROM `smf_messages` WHERE `id_board` = 18 AND `id_topic` = " . $display . " AND `id_msg` = " . $display2;
      $result2 = mysqli_query($con,$qry);
      //echo $qry;
      if(!$result2) {
          echo "<center><p>Couldn't fetch news posts. Error code 3.</p></center>";
      } else {
          while($show = mysqli_fetch_array($result,MYSQLI_ASSOC))
          {
              echo "<center><h1>" . $show['subject'] . "</h1></center><br /><br />";
              echo "<center>" . $show['body'] . "</center><br />";
          }
      }
      mysqli_free_result($result);
      mysqli_free_result($result2);
      mysqli_close($con);
  

它应该从数据库中获取我的基于smf的论坛的最新主题，从新闻板中获得最高的主题id，但最低的帖子id。它似乎正在做查询只是很好，因为我没有得到任何错误，但它不显示主题或主体。我该怎么办?

Answer 1

您的$result变量是错误的第二次查询获取。对于第二个查询

 while($show = mysqli_fetch_array($result,MYSQLI_ASSOC))

应该

 while($show = mysqli_fetch_array($result2,MYSQLI_ASSOC))
                                         ^