thinkphp中怎么实现左右值无限分类

tangjin

作者

本篇文章为大家展示了thinkphp中怎么实现左右值无限分类，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。

以前一直使用父子无限分类，这种分类结构清晰，使用也简单。但若分类数量很大的话，在查询上性能不佳。比如在做导航菜单中，我要根据某一分类查询出整个分类树的话（祖辈）。性能消耗是非常大的，要么做递归，要么做多次查询。故，对于分类的数据量很大的情况，我推荐使用左右值，以减少查询上的麻烦。

thinkphp中怎么实现左右值无限分类

代码如下:

_id /** +---------------------------------------------------------- * 构造函数 * @access public * @return void +---------------------------------------------------------- */ public function __construct($left,$right,$id){ parent::__construct(); $this->_left = $left; $this->_right = $right; $this->_id = $id; } /** +---------------------------------------------------------- * 根据node$this->_id得到该node的所有值 * @access public * @param $nodeId * @return array +---------------------------------------------------------- */ public function getNodeById($nodeId) { if($nodeId>0) { return $this->getById($nodeId); } else { throw_exception('未知$this->_id'); return false; } } /** +---------------------------------------------------------- * 获取父节点,含直属父类（type=1），所有父类：type=0 * @access public * @param $nodeId int 节点$this->_id * @return $parentNode array() +---------------------------------------------------------- */ public function getParentNode($nodeId,$type = 0) { if($nodeId == 0) throw_exception('未知$this->_id');; $currentNode = $this->getNodeById($nodeId); if($currentNode) { $condition = " ".$this->_left.'<'.$currentNode[$this->_left].' and '.$this->_right.' >'.$currentNode[$this->_right]." "; if($type ==1) //直属父类 { return $this->where($condition)->order($this->_left." DESC")->limit(1)->find(); // $sql = "SELECT * FROM ".TABLE_NAME." WHERE {$condition} ORDER BY ".$this->_left." DESC LIMIT 1"; // return mysql_query($sql) or die(mysql_error()); } else if($type ==0) { return $this->where($condition)->findAll(); // $sql = "SELECT * FROM ".TABLE_NAME." WHERE {$condition} "; // return mysql_query($sql) or die(mysql_error()); } } else { return false; } } /** +---------------------------------------------------------- * 当前节点下子孙节点总数.子孙总数＝（当前节点的右值 - 当前节点的左值-1）/2 * @access public * @param $node_id int 节点$this->_id * @return $amount int 该节点下的子孙总数 * +---------------------------------------------------------- */ public function getChildCount($nodeId) { $currentNode = $this->getNodeById($nodeId); if(!empty($currentNode)) { return (int)($currentNode[$this->_right]-$currentNode[$this->_left] -1)/2; } } /** +---------------------------------------------------------- * 获取当前节点下所有子节点。当 A子类的右节点=B子类左节点-1 则 A、B属于同一级别 * @access public * @param $curentId * @param $type int 0：当前节点下所有子类，1为当前节点下一级子类 * @return bool +---------------------------------------------------------- */ public function getChild($nodeId,$type=0) { $currentNode = $this->getNodeById($nodeId); if($currentNode[$this->_left]-$currentNode[$this->_right] ==1) { return false; //当该节点左值 - 右值=1 时，其下没有子节点。 } else { $condition = $this->_left.'>'.$currentNode[$this->_left].' and '.$this->_right .'<'.$currentNode[$this->_right]; $child = $this->where($condition)->findAll(); if($type == 0)//所有子类 { return $child; } else if($type ==1) //获取当前节点下一级分类 { $subArr = array(); //一级子类 foreach ($child as $k=>$sub) { //子类的左节点=父类左节点+1，则子类为第一个子类 if($sub[$this->_left]==$currentNode[$this->_left]+1) { //$right = $sub[$k][$this->_right]; //当前节点的右节点 $firstSub = $sub; //当前节点下第一个子类 array_push($subArr,$firstSub); //子类入栈 unset($child[$k]); } } $rightVal = $firstSub[$this->_right]; //第一个子节点为比较标志 $childCount = count($child);//剩余子节点数 for($i=0;$i<$childCount;$i++) //循环检索出同级子节点 { foreach ($child as $key => $sub2) { if($rightVal == $sub2[$this->_left]-1) { $rightVal = $sub2[$this->_right]; //把循环当前的node的右节点当做比较值 array_push($subArr,$sub2); unset($child[$key]); } } } return $subArr; } } } /** +---------------------------------------------------------- * 返回当前节点的完整路径 * @access public * @param $nodeId * @return array +---------------------------------------------------------- */ public function getSinglePath($nodeId) { $sql = "select parent.* from __TABLE__ as node,__TABLE__ as parent where node.{$this->_left} between parent.{$this->_left} AND parent.{$this->_right} AND node.{$this->_id} = {$nodeId} order by parent.{$this->_left}";// echo $sql; return $this->query($sql); } /** +---------------------------------------------------------- * 添加子节点，分3种：0：在当前节点下最后追加一个子节点；1：在当前节点下追加第一个子节点；

2：在当前节点下的某个子节点后追加

复制代码代码如下:

* @access public * @param $currentId int * @param $nodeName string 新节点名称 * @param $targetId int 追加到当前节点下子节点的指定节点后 * @return bool +---------------------------------------------------------- */ public function addNode($nodeId,$newData,$type=0,$targetId=0) { if(empty($newData)) { throw_exception('新分类不能为空'); } $currentNode = $this->getNodeById($nodeId); switch ($type) { case 0: $leftNode = $currentNode[$this->_right]; //新节点的左值为父节点的右值 $rightNode = $leftNode+1; break; case 1: $leftNode = $currentNode[$this->_left]+1; //新节点的左值为父节点的左值+1 $rightNode = $leftNode+1; break; case 2: $otherNode = $this->getNodeById($targetId); $leftNode = $otherNode[$this->_right]+1; $rightNode = $leftNode+1; default: break; }// $sql = "UPDATE ".TABLE_NAME." SET ".$this->_right."=".$this->_right."+2 WHERE ".$this->_right." >= ".$leftNode;// $sql2 = "UPDATE ".TABLE_NAME." SET ".$this->_left."=".$this->_left."+2 WHERE ".$this->_left.">".$leftNode; $this->setInc($this->_right,$this->_right.">=".$leftNode,2); //把所有右值大于新节点左值的节点的右值+2,注意效率 $this->setInc($this->_left,$this->_left.">".$leftNode,2); //把所有大于新节点的左值+2 $newData[$this->_left] = (int)$leftNode; $newData[$this->_right] =(int) $rightNode; return $this->add($newData); } /** +---------------------------------------------------------- * 删除节点 * @access public * @param type 操作类型，默认为0删除当前节点下的所有子节点，1为删除包括自身的节点 * @param $nodeId int 要删除的$this->_id * @return bool +---------------------------------------------------------- */ public function rmNode($nodeId,$type =1) { $currentNode = $this->getNodeById($nodeId); if($type == 1) //删除包含自身的节点 { $sql = "DELETE FROM __TABLE__ WHERE ".$this->_left.">= {$currentNode[$this->_left]} AND ".$this->_right."<= {$currentNode[$this->_right]}"; $childCount = ($this->getChildCount($nodeId)+1)*2; //要更新的值 $sql2 = "UPDATE __TABLE__ SET ".$this->_right."=".$this->_right."-".$childCount." WHERE ".$this->_right.">".$currentNode[$this->_right]; $sql3 = "UPDATE __TABLE__ SET ".$this->_left."=".$this->_left."-".$childCount." WHERE ".$this->_left.">".$currentNode[$this->_left]; } else //删除当前节点下的所有节点 { $sql ="DELETE FROM __TABLE__ WHERE ".$this->_left."> {$currentNode[$this->_left]} AND ".$this->_right."< {$currentNode[$this->_right]}"; $childCount = $this->getChildCount($nodeId)*2; //要更新的值 $sql2 = "UPDATE __TABLE__ SET ".$this->_right."=".$this->_right ."-".$childCount." WHERE ".$this->_right.">=".$currentNode[$this->_right]; $sql3 = "UPDATE __TABLE__ SET ".$this->_left."=".$this->_left."-".$childCount." WHERE ".$this->_left.">".$currentNode[$this->_left]; } $this->execute($sql); $this->execute($sql2); $this->execute($sql3); return true; } /** +---------------------------------------------------------- * 修改节点，名称等 * @access public * @param $newData array()必须含有要修改的$this->_id,k-v必须对齐，如arr['node_name'] = '商品' * @return bool +---------------------------------------------------------- */ public function modiNode($newData) { if(!empty($newData)) { $id = $newData[$this->_id]; unset($newData[$this->_id]); return $this->save($newData,$this->_id.'='.$id); } }}?>

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发布于 2021-07-09 21:19:14

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