Question

问题：

我试图通过使用类删除类别的所有子级别。目前我只能删除两个子级别，而不是三个。

数据库表：

CREATE TABLE betyg_category (
  CID int(11) NOT NULL AUTO_INCREMENT,
  Item varchar(100) NOT NULL,
  Parent int(11) NOT NULL DEFAULT '0',
  PRIMARY KEY (CID)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

PHP类：

<?php
class ItemTree 
{ 
   var $itemlist = array();

   function ItemTree($query)
   {
      $result = mysql_query($query) or die ('Database Error (' . mysql_errno() . ') ' . mysql_error());

      while ($row = mysql_fetch_assoc($result)) 
      {
         $this->itemlist[$row['CID']] = array(
           'name'   => $row['Name'],
           'parent' => $row['Parent']
         );
      }
   }

   function get_tree($parent, $with_parent=0)
   {
      $item_tree = array();

      if ($with_parent == 1 && $parent != 0) 
      {
         $item_tree[$parent]['name'] = $this->itemlist[$parent]['name'];
         $item_tree[$parent]['parent'] = $this->itemlist[$parent]['parent'];
         $item_tree[$parent]['child'] = $this->get_tree($parent);

         return $item_tree;
      }

      foreach ($this->itemlist as $key => $val) 
      {
         if ($val['parent'] == $parent) 
         {
               $item_tree[$key]['name'] = $val['name'];
               $item_tree[$key]['parent'] = $val['parent'];
               $item_tree[$key]['child'] = $this->get_tree($key);
         }
      }

      return $item_tree;
   }

   function make_optionlist ($id, $class='', $delimiter='/')
   {
      $option_list = '';

      $item_tree = $this->get_tree(0);

      $options = $this->make_options($item_tree, '', $delimiter);

      if (!is_array($id)) 
      {
         $id = array($id);
      }

      foreach($options as $row) 
      {
         list($index, $text) = $row;
         $selected = in_array($index, $id) ? ' selected="selected"' : '';
         $option_list .= "<option value=\"$index\" class=\"$class\"$selected>$text</option>\n";
      }

      return $option_list;
   }

   function make_options ($item_tree, $before, $delimiter='/')
   {
      $before .= empty($before) ? '' : $delimiter;

      $options = array();

      foreach ($item_tree as $key => $val) 
      {
         $options[] = array($key, '-&nbsp;'.$before.$val['name']);
         if (!empty($val['child'])) {
            $options = array_merge($options, $this->make_options($val['child'], $before.$val['name'], $delimiter));
         }
      }

      return $options;
   }

   function get_navlinks ($navid, $tpl, $startlink='', $delimiter=' &raquo; ')
   {
      // $tpl typ: <a href="index.php?id={id}" class="navlink">{name}</a>

      $search = array('{id}', '{name}');

      $navlink = array();

      while (isset($this->itemlist[$navid])) 
      {
         $replace = array($navid, $this->itemlist[$navid]['name']);
         $navlink[] = str_replace($search, $replace, $tpl);
         $navid = $this->itemlist[$navid]['parent'];
      }

      if (!empty($startlink)) 
      {
         $navlink[] = str_replace($search, array(0, $startlink), $tpl);
      }

      $navlink = array_reverse($navlink);

      return implode($delimiter, $navlink);
   }

   function show_tree ($parent=0, $tpl='%s', $ul_class='', $li_class='')
   {
      $item_tree = $this->get_tree($parent);

      return $this->get_node($item_tree, $parent, $tpl, $ul_class, $li_class);
   }

   function get_node ($item_tree, $parent, $tpl, $ul_class, $li_class)
   {
      // $tpl typ: <a href="item.php?id={id}" class="treelink" style="color:blue">{name}</a>

      $search = array('{id}', '{name}'); 

      $output = "\n<ul class=\"$ul_class\">\n";

      foreach ($item_tree as $id => $item) 
      {
         $replace = array($id, $item['name']);
         $output .= "<li class=\"$li_class\">".str_replace($search, $replace, $tpl);
         $output .= !empty($item['child']) ? "<br />".$this->get_node ($item['child'], $id, $tpl, $ul_class, $li_class) : '';
         $output .= "</li>\n";
      }

      return $output . "</ul>\n"; 
   }

   function get_id_in_node ($id)
   {
      $id_list = array($id);

      if (isset($this->itemlist[$id])) 
      {
         foreach ($this->itemlist as $key => $row) 
         {
            if ($row['parent'] == $id) 
            {
               if (!empty($row['child'])) 
               {
                 $id_list = array_merge($id_list, get_id_in_node($key));
               } else 
               {
                 $id_list[] = $key;
               }
            }
         }

      }
      return $id_list;
   }

   function get_parent ($id)
   {
      return isset($this->itemlist[$id]) ? $this->itemlist[$id]['parent'] : false;
   }

   function get_item_name ($id)
   {
      return isset($this->itemlist[$id]) ? $this->itemlist[$id]['name'] : false;
   }
}
?>

情境：

假设你在a：

中有以下结构

文学
- 来源整合
----测试1

它将在数据库表中产生以下结果：

Categories

当我尝试删除这个子级时，它会将最后一个子级别留在数据库中，同时它应该删除它。结果将是：

Deleted categories

PHP代码：

//Check if delete button is set
if (isset($_POST['submit-deletecategory'])) 
{
    //Get $_POST variables for category id
    $CategoryParent = intval($_POST['CategoryList']);

    //Check if category is selected
    if ($CategoryParent != "#") 
    {
        //Get parent category and subsequent child categories
        $query = "SELECT CID, Item AS Name, Parent FROM " . TB_CATEGORY . " ORDER BY Name";
        $items = new ItemTree($query);

        if ($items->get_item_name($_POST['CategoryList']) !== false) 
        {
            //Build up erase list
            $CategoryErase = $items->get_id_in_node($CategoryParent);
            $CategoryEraseList = implode(", ", $CategoryErase);
        } 
        else 
        {
            $CategoryEraseList = 0;
        }

        //Remove categories from database
        $query = "DELETE FROM " . TB_CATEGORY . " WHERE CID IN ($CategoryEraseList)";
        $result = mysql_query($query) or die ('Database Error (' . mysql_errno() . ') ' . mysql_error());

       //Return a confirmation notice
       header("Location: settings.php");
       exit;
    }
}

提前感谢您提供解决问题的任何指导。

Answer 1

这是一种方法：使用递归函数，它首先查找叶子项（树中最深的）。您首先删除子项，然后删除父项。对于每个孩子，您首先要移除孩子的孩子等等......

deleteSub(1);

function deleteSub($cat_id) {
    $request = "SELECT * FROM ". TB_CATEGORY ." WHERE Parent = ".$cat_id;
    $results = mysql_query($request);
    while($child = mysql_fetch_array($results)) 
    {
        deleteSub($child["CID"]);
    }
    $request = "DELETE FROM ". TB_CATEGORY ." WHERE CID = ".$cat_id;
    return mysql_query($request);
}

更好的方法是使用这种递归函数将CID存储在数组中，然后发出一个DELETE请求，但我认为你将能够调整这段代码。

Answer 2

我不打算阅读或尝试理解整个代码，但在我看来，你需要某种递归函数。我基本上要做的是创建一个在层次结构中上升的函数和一个下降的函数。

注意：已经有一段时间了，因为我已经在过程mysql中写了任何东西，所以请检查mysql_num_rows（），mysql_fetch_array等是否以正确的方式编写

编辑：我刚刚注意到你只想要向下删除，因此samsamX的答案更有效

<?php
function recursiveParent($id) {
    $sql = 'SELECT parent FROM betyg_category WHERE CID=' . $id;
    $result = mysql_query($sql);

    if(mysql_num_rows($result) > 0) {
        while($r = mysql_fetch_array($result,MYSQLI_ASSOC)) {
            recursiveParent($r['parent']);
        }
    }

    $sql = 'DELETE FROM betyg_category WHERE CID=' . $id;
    mysql_query($sql);
}

function recursiveChild($parent) {
    $sql = 'SELECT CID FROM betyg_category WHERE parent=' . $parent;
    $result = mysql_query($sql);

    if(mysql_num_rows($result) > 0) {
        while($r = mysql_fetch_array($result,MYSQLI_ASSOC)) {
            recursiveChild($r['CID']);
        }
    }

    $sql = 'DELETE FROM betyg_category WHERE parent=' . $parent;
    mysql_query($sql);
}

function delete($id) {
    recursiveParent($id);
    recursiveChild($id);
}
?>

Answer 3

这是我的方法。而不是递归查询运行，我先得到所有孩子的id然后只运行查询。这里的代码参考： -

首先，将名为$ delete_node_list的变量定义为数组。（存储需要删除的所有节点ID）

function delete_child_nodes($node_id)
{           
    $childs_node = $this->edirectory_model->get_child_nodes($node_id);


    if(!empty($childs_node))
    {
        foreach($childs_node as $node)
        {
            $this->delete_child_nodes($node['id']);
        }   
    }

    $this->delete_node_list[] = $node_id;
}

在mysql中

..

 $sql = 'DELETE FROM betyg_category WHERE CID IN '.$this->delete_node_list;
 mysql_query($sql);

使用PHP删除select中所有类别的子级别

3 个答案: