创建动态PHP/HTML类别树

我已经知道了如何使用ul>li结构获取每个父/子，但现在我陷入了困境，子类别ul需要一个类“下拉列表”，但无法解决这个问题

我的目标是创建一个具有基础NavaMLUP的无限动态UL菜单。

PHP

显示cat的代码

 <?php
  $res = fetchCategoryTreeList();
    foreach ($res as $r) {
      echo $r;
    }
  ?>

输出

<ul>
  <li class='has-dropdown'>Golf Equipment</li>

    <ul>
        <li class=''>Manual Golf Trolleys</li>
        <li class=''>Electric Golf Trolleys</li>
    </ul>

  <li class='has-dropdown'>Weight Training</li>

    <ul>
        <li class=''>Weight Benches</li>
        <li class=''>Weights</li>
    </ul>
  </li>
</ul>

---

我的天哪，能帮上忙吗。。我不知道需要什么课程的下拉列表。。。你可以给主要的ul一个等级

$user_tree_array[] = "<ul  class='main_ul'>";

功能：

<?php

    function fetchCategoryTreeList( $parent = 0, $user_tree_array = "" ) {

        if ( ! is_array($user_tree_array))
            $user_tree_array = array();


        $sql  = "SELECT id,name,parent ";
        $sql .= "FROM `categories` ";
        $sql .= "WHERE 1 AND parent = {$parent} ";
        $sql .= "ORDER BY id ASC";

        if ( database_querySelect( $sql, $rows) )
        {

            foreach ( $rows as $row ) 
            {

                $user_tree_array[] = "<li class='' >{$row["name"]}</li>";

                if ( $parent != $row["id"] )
                {

                    $user_tree_array[] = "<ul>";

                    $user_tree_array = fetchCategoryTreeList( $connection, $row["id"], $user_tree_array );

                    $user_tree_array[] = "</ul>";

                }
                else
                { 

                    $user_tree_array = fetchCategoryTreeList( $row["id"], $user_tree_array );               

                }

            }

        }

        return $user_tree_array;

    }

?>

电话：

 .main_ul .has-dropdown ul {
}

<?php

    function fetchCategoryTreeList( $parent = 0, $user_tree_array = "" ) {

        if ( ! is_array($user_tree_array))
            $user_tree_array = array();


        $sql  = "SELECT id,name,parent ";
        $sql .= "FROM `categories` ";
        $sql .= "WHERE 1 AND parent = {$parent} ";
        $sql .= "ORDER BY id ASC";

        if ( database_querySelect( $sql, $rows) )
        {

            foreach ( $rows as $row ) 
            {

                $user_tree_array[] = "<li class='' >{$row["name"]}</li>";

                if ( $parent != $row["id"] )
                {

                    $user_tree_array[] = "<ul>";

                    $user_tree_array = fetchCategoryTreeList( $connection, $row["id"], $user_tree_array );

                    $user_tree_array[] = "</ul>";

                }
                else
                { 

                    $user_tree_array = fetchCategoryTreeList( $row["id"], $user_tree_array );               

                }

            }

        }

        return $user_tree_array;

    }

?>

<?php

    $arrays = fetchCategoryTreeList();

    foreach ( $arrays as $list) 
    {
        echo $list;
    }

?>