如何从数据库表创建列表视图

Question

我正在查询类别表id, parent_id, name，以生成所有类别和子类别的列表视图。到目前为止，我拥有的是：

• HP
  • 笔记本电脑
  • PC
• 体育
  • 太阳镜
• 食物
• House

我用来生成输出的函数是：

public function get_category($parent_id = NULL)
{ 
$query = $this->db->get_where('category', array('parent_id' => $parent_id))->result();
$result = '';
foreach ($query as $row)
{
$i = 0;
if ($i == 0) 
{
$result .= '<ul>';  
}
$result .= '<li><a href="'.base_url().'category/edit/'.$row->id.'">' . $row->name;
$result .= $this->get_category($row->id);
$result .= '</li>';
$i++;
if ($i > 0) 
{
$result .= '</ul>';
}
}
return $result;
}

这就是我想要实现的：

HP
HP > Laptops
HP > PC
Sports
Sports > Sunglasses
Food
House

Answer 1

尝试以下

public function get_category($parent_id = NULL,$level, $prev = "")
{ 
$query = $this->db->get_where('category', array('parent_id' => $parent_id))->result();
$result = '';
foreach ($query as $row)
{
$temp = $prev;
if($level == 0){
$temp .= '<a href="'.base_url().'category/edit/'.$row->id.'">' . $row->name.'</a>';
}else{
$temp .= ' &gt; <a href="'.base_url().'category/edit/'.$row->id.'">' . $row->name.'</a>';
}
$result .= $temp;
$result .= "<br />";
$result .= $this->get_category($row->id, $level + 1, $temp);
}
return $result;
}

此功能的第一次运行应该是

get_category(NULL, 0, "");

此处

• NULL是父id(您可以使用循环来动态地传递id(
• level应为0
• prev应为空

Answer 2

我已经根据您的需求创建了一个演示，它对我很有效。我正在分享下面的代码，我已经在必要的地方在评论中进行了解释。看看它是否对你有帮助

控制器

public function get_category($parent_id = NULL){ 
// get the {category}, {sub_category} from the table, if {sub_category} stored in different table use {JOIN}
$data['category'] = $this->db->get_where('category', array('parent_id' => $parent_id))->result();  
$this->load->view('your-view', $data); 
}

查看

<?php 
if(!empty($category)){ // check if {$category} has value; if not, do nothing
$catArr = array();  // initialize array to store category id
?>
<ul>  <!-- Start ul -->
<?php 
foreach($category as $cat){ //loop through all the {category} array
// check if the {cat_id} already exists in array; if not, do so where {cat_id} is category id(change your value here)
if( ! in_array( $cat->cat_id, $catArr ) ){ 
$catArr[] = $cat->event_id;
?>  
<li><?php echo $cat->cat_name; ?></li>  <!-- show {cat_name} in list -- your category name here -->
<?php
}
?>
<!-- Show {cat_name} and {subcat_name} both -- (your values here). Give links or whatever here(your styling)-->
<li><?php echo $cat->cat_name; ?> &gt; <?php echo $cat->subcat_name; ?></li>
<?php
} 
?>
</ul>
<?php 
} 
?>

输出

Honda
Honda > Car
Honda > Bike
Philips 
Philips > Electricals
Philips > Electronics