显示类别和子类别的下拉菜单

Question

我试图在下拉菜单中显示的类别和子类别，我有这样的：

<?php 


       $cat_query = "SELECT * FROM `categories`"; 
       $select_categories = mysqli_query($connection, $cat_query); 
       while ($cat = mysqli_fetch_array($select_categories)) { 

       $cat_id = $cat['cat_id']; 
       $cat_title = $cat['cat_title']; 

       echo "<li>"; 
       echo "<a href='#'>$cat_title <span class='caret'></span></a>"; 

       $sub_query = "SELECT * FROM `sub_categories` WHERE `cat_id` = $cat_id"; 
       $select_sub_categories = mysqli_query($connection, $sub_query); 

       while ($sub = mysqli_fetch_array($select_sub_categories)) { 

        $subcat_id = $sub['subcat_id']; 
        $subcat_title = $sub['subcat_title']; 
        echo "<ul class='dropdown-menu'><li>"; 
        echo "<a href='#'>$subcat_title</a></li>"; 
        echo "</ul>"; 
       } 

        echo "</li>"; 

       } 

      ?> 

它实际上是从数据库中获取的类别，但它无法正确显示。

在桌面版本，它显示是这样的： Desktop View

在移动版本，它显示是这样的： Mobile View

难道我做错了什么？ 任何帮助将不胜感激。 感谢

Answer 1

既然你没有提供的css，JavaScript或一些HTML代码，我认为这个问题是在这个PHP块

while ($sub = mysqli_fetch_array($select_sub_categories)) { 

       $subcat_id = $sub['subcat_id']; 
       $subcat_title = $sub['subcat_title']; 
       echo "<ul class='dropdown-menu'><li>"; 
       echo "<a href='#'>$subcat_title</a></li>"; 
       echo "</ul>"; 
      } 

从它好像你正在创建下拉列表这个代码块所以也许它应该是

echo "<ul class='dropdown-menu'>"; 
while ($sub = mysqli_fetch_array($select_sub_categories)) { 

       $subcat_id = $sub['subcat_id']; 
       $subcat_title = $sub['subcat_title']; 
       echo "<li><a href='#'>$subcat_title</a></li>"; 
} 
echo "</ul>"; 

如果这不起作用您应该再次检查您的JavaScript，CSS，HTML代码。因为我不知道你的设计计划