PHP 回显在查询后重复

Question

我想要一个从数据库获取值的SQL Select语句，如果有任何结果，则在下拉菜单中显示一个Form和结果。

目前，它获取值，但表单与结果的次数相呼应。例如，如果查询有 1 个结果，它将回显表单一次。2.结果，回声形式两次，依此类推。我希望表单显示一次，但下拉列表包含所有结果。

如果有人能给我指出正确的方向，那就太好了。谢谢

包含 2 个来自数据库的结果的图像

<?php

            include("conndetails.php");     

            $conn = new mysqli($servername, $username, $password, $dbname);

            $sql    = "SELECT website_name FROM user_websites WHERE username='$_SESSION[user]'"; //Selects all the websites for the user that is logged in. 

            $result = $conn->query($sql);

              if ($result->num_rows > 0) {

                  while ($row = $result->fetch_assoc()) {

    echo '<h2>Download a website</h2>

          <form action="downloads.php" method="get">

          <select id="website_name" name="website_name">

          <option name="website_name">'. $row["website_name"]. '

          </option>

          </select>

          <input type="submit" value="Download">

          </form>

          <br>

          <hr>

          <h2>Upload to a website</h2>

          <form action="upload.php" method="post" enctype="multipart/form-data"> 

          <p>Select file to upload:</p>

          <input type="file" name="zip_file" id="fileToUpload">

          <p>Select a website to upload to:</p>

          <select id="website_upload_name" name="website_upload_name">

          <option name="website_upload_name">'. $row["website_name"]. '

          </option>

          </select>

          <br>

          <br>

          <input type="submit" value="Upload" name="submit" style="position:relative; left: -1px;">

          </form>

          <br>

          <hr>';

             }}

    ?>

Answer 1

创建一个变量，并在返回数据时添加到该变量中。不要将所有代码都放在 .$options<option>htmlwhileif ($result->num_rows > 0) {&nbsp; &nbsp;//Declare $options&nbsp; &nbsp;$options = '';&nbsp; &nbsp;while ($row = $result->fetch_assoc()) {&nbsp; &nbsp; &nbsp; //Adding <option> to the var $options&nbsp; &nbsp; &nbsp; $options .= '<option name="website_name">'. $row["website_name"]. '&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </option>';&nbsp; &nbsp; }&nbsp; &nbsp; //HTML once, first part&nbsp; &nbsp;$html = '<h2>Download a website</h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <form action="downloads.php" method="get">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <select id="website_name" name="website_name">';&nbsp; &nbsp;//Adding <option> to the <select>&nbsp; &nbsp;$html .= $options;&nbsp; &nbsp;//HTML once, second part&nbsp; &nbsp;$html .= '</select>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <input type="submit" value="Download">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </form>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <hr>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <h2>Upload to a website</h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <form action="upload.php" method="post" enctype="multipart/form-data">&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <p>Select file to upload:</p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <input type="file" name="zip_file" id="fileToUpload">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <p>Select a website to upload to:</p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <select id="website_upload_name" name="website_upload_name">'&nbsp; &nbsp; //Adding <option> to the second <select>&nbsp; &nbsp; $html .= $options;&nbsp; &nbsp; //HTML once, third part&nbsp; &nbsp; $html .= '</select>&nbsp; &nbsp; &nbsp; <br>&nbsp; &nbsp; &nbsp; <br>&nbsp; &nbsp; &nbsp; <input type="submit" value="Upload" name="submit" style="position:relative; left: -1px;">&nbsp; &nbsp; &nbsp; </form>&nbsp; &nbsp; &nbsp; <br>&nbsp; &nbsp; &nbsp; <hr>';&nbsp; //Printing&nbsp; echo $html;&nbsp; }

Answer 2

它回显的时间与找到的结果一样多的原因是，您已经将回显语句放在 while 构造中。如果您希望回显仅在验证 if 语句的条件时显示一次，请移动回显到 while 外部，并将选项的 html 代码放在变量中，您将在一段时间内构建这些变量。在这里，我想这两个组合都需要具有与原始代码相同的选项：if ($result->num_rows > 0) {$options = '';&nbsp; while ($row = $result->fetch_assoc()) {&nbsp; &nbsp; $options .= '<option name="website_name">'. $row["website_name"]. '</option>';&nbsp; &nbsp;&nbsp;&nbsp; }&nbsp; echo '<h2>Download a website</h2>&nbsp; &nbsp; &nbsp; &nbsp; <form action="downloads.php" method="get">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <select id="website_name" name="website_name">' . $options . '</select>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <input type="submit" value="Download">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</form>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<hr>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<h2>Upload to a website</h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<form action="upload.php" method="post" enctype="multipart/form-data">&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<p>Select file to upload:</p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<input type="file" name="zip_file" id="fileToUpload">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<p>Select a website to upload to:</p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<select id="website_upload_name" name="website_upload_name">' . $options . '</select>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<input type="submit" value="Upload" name="submit" style="position:relative; left: -1px;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</form>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<hr>';}