解析thinkphp的左右值無(wú)限分類

2020-03-22 20:27:28

字體：大中小

供稿：網(wǎng)友

以前一直使用父子無(wú)限分類，這種分類結(jié)構(gòu)清晰，使用也簡(jiǎn)單。但若分類數(shù)量很大的話，在查詢上性能不佳。比如在做導(dǎo)航菜單中，我要根據(jù)某一分類查詢出整個(gè)分類樹的話（祖輩）。
性能消耗是非常大的，要么做遞歸，要么做多次查詢。故，對(duì)于分類的數(shù)據(jù)量很大的情況，我推薦使用左右值，以減少查詢上的麻煩。
復(fù)制代碼代碼如下:
_id
/**
+----------------------------------------------------------
* html' target='_blank'>構(gòu)造函數(shù)
* @access public
* @return void
+----------------------------------------------------------
*/
public function __construct($left,$right,$id){
parent::__construct();
$this- _left = $left;
$this- _right = $right;
$this- _id = $id;
}
/**
+----------------------------------------------------------
* 根據(jù)node$this- _id得到該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;
}
}
/**
+----------------------------------------------------------
* 獲取父節(jié)點(diǎn),含直屬父類（type=1），所有父類：type=0
* @access public
* @param $nodeId int 節(jié)點(diǎn)$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) //直屬父類
{
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;
}
}
/**
+----------------------------------------------------------
* 當(dāng)前節(jié)點(diǎn)下子孫節(jié)點(diǎn)總數(shù).子孫總數(shù)＝（當(dāng)前節(jié)點(diǎn)的右值 - 當(dāng)前節(jié)點(diǎn)的左值-1）/2
* @access public
* @param $node_id int 節(jié)點(diǎn)$this- _id
* @return $amount int 該節(jié)點(diǎn)下的子孫總數(shù) *
+----------------------------------------------------------
*/
public function getChildCount($nodeId)
{
$currentNode = $this- getNodeById($nodeId);
if(!empty($currentNode))
{
return (int)($currentNode[$this- _right]-$currentNode[$this- _left] -1)/2;
}
}
/**
+----------------------------------------------------------
* 獲取當(dāng)前節(jié)點(diǎn)下所有子節(jié)點(diǎn)。當(dāng) A子類的右節(jié)點(diǎn)=B子類左節(jié)點(diǎn)-1 則 A、B屬于同一級(jí)別
* @access public
* @param $curentId
* @param $type int 0：當(dāng)前節(jié)點(diǎn)下所有子類，1為當(dāng)前節(jié)點(diǎn)下一級(jí)子類
* @return bool
+----------------------------------------------------------
*/
public function getChild($nodeId,$type=0)
{
$currentNode = $this- getNodeById($nodeId);
if($currentNode[$this- _left]-$currentNode[$this- _right] ==1)
{
return false; //當(dāng) 該節(jié)點(diǎn)左值 - 右值=1 時(shí)，其下沒有子節(jié)點(diǎn)。
}
else
{
$condition = $this- _left.' '.$currentNode[$this- _left].' and '.$this- _right .' '.$currentNode[$this- _right];
$child = $this- where($condition)- findAll();
if($type == 0)//所有子類
{
return $child;
}
else if($type ==1) //獲取當(dāng)前節(jié)點(diǎn)下一級(jí)分類
{
$subArr = array(); //一級(jí)子類
foreach ($child as $k= $sub) {
//子類的左節(jié)點(diǎn)=父類左節(jié)點(diǎn)+1，則子類為第一個(gè)子類
if($sub[$this- _left]==$currentNode[$this- _left]+1)
{
//$right = $sub[$k][$this- _right]; //當(dāng)前節(jié)點(diǎn)的右節(jié)點(diǎn)
$firstSub = $sub; //當(dāng)前節(jié)點(diǎn)下第一個(gè)子類
array_push($subArr,$firstSub); //子類入棧
unset($child[$k]);
}
}
$rightVal = $firstSub[$this- _right]; //第一個(gè)子節(jié)點(diǎn)為比較標(biāo)志
$childCount = count($child);//剩余子節(jié)點(diǎn)數(shù)
for($i=0;$i $childCount;$i++) //循環(huán)檢索出同級(jí)子節(jié)點(diǎn)
{
foreach ($child as $key = $sub2) {
if($rightVal == $sub2[$this- _left]-1)
{
$rightVal = $sub2[$this- _right]; //把循環(huán)當(dāng)前的node的右節(jié)點(diǎn)當(dāng)做比較值
array_push($subArr,$sub2);
unset($child[$key]);
}
}
}
return $subArr;
}
}
}
/**
+----------------------------------------------------------
* 返回當(dāng)前節(jié)點(diǎn)的完整路徑
* @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);
}
/**
+----------------------------------------------------------
* 添加子節(jié)點(diǎn)，分3種：0：在當(dāng)前節(jié)點(diǎn)下最后追加一個(gè)子節(jié)點(diǎn)；1：在當(dāng)前節(jié)點(diǎn)下追加第一個(gè)子節(jié)點(diǎn)；

2：在當(dāng)前節(jié)點(diǎn)下的某個(gè)子節(jié)點(diǎn)后追加
復(fù)制代碼代碼如下:
* @access public
* @param $currentId int
* @param $nodeName string 新節(jié)點(diǎn)名稱
* @param $targetId int 追加到當(dāng)前節(jié)點(diǎn)下子節(jié)點(diǎn)的指定節(jié)點(diǎn)后
* @return bool
+----------------------------------------------------------
*/
public function addNode($nodeId,$newData,$type=0,$targetId=0)
{
if(empty($newData))
{
throw_exception('新分類不能為空');
}
$currentNode = $this- getNodeById($nodeId);
switch ($type) {
case 0:
$leftNode = $currentNode[$this- _right]; //新節(jié)點(diǎn)的左值為父節(jié)點(diǎn)的右值
$rightNode = $leftNode+1;
break;
case 1:
$leftNode = $currentNode[$this- _left]+1; //新節(jié)點(diǎn)的左值為父節(jié)點(diǎn)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); //把所有右值大于新節(jié)點(diǎn)左值的節(jié)點(diǎn)的右值+2,注意效率
$this- setInc($this- _left,$this- _left." ".$leftNode,2); //把所有大于新節(jié)點(diǎn)的左值+2
$newData[$this- _left] = (int)$leftNode;
$newData[$this- _right] =(int) $rightNode;
return $this- add($newData);
}
/**
+----------------------------------------------------------
* 刪除節(jié)點(diǎn)
* @access public
* @param type 操作類型，默認(rèn)為0刪除當(dāng)前節(jié)點(diǎn)下的所有子節(jié)點(diǎn)，1為刪除包括自身的節(jié)點(diǎn)
* @param $nodeId int 要?jiǎng)h除的$this- _id
* @return bool
+----------------------------------------------------------
*/
public function rmNode($nodeId,$type =1)
{
$currentNode = $this- getNodeById($nodeId);
if($type == 1) //刪除包含自身的節(jié)點(diǎn)
{
$sql = "DELETE FROM __TABLE__ WHERE ".$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 //刪除當(dāng)前節(jié)點(diǎn)下的所有節(jié)點(diǎn)
{
$sql ="DELETE FROM __TABLE__ WHERE ".$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;
}
/**
+----------------------------------------------------------
* 修改節(jié)點(diǎn)，名稱等
* @access public
* @param $newData array()必須含有要修改的$this- _id,k-v必須對(duì)齊，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);
}
}
}
?

PHP教程

鄭重聲明：本文版權(quán)歸原作者所有，轉(zhuǎn)載文章僅為傳播更多信息之目的，如作者信息標(biāo)記有誤，請(qǐng)第一時(shí)間聯(lián)系我們修改或刪除，多謝。

上一篇：PHP自定義圖片縮放函數(shù)實(shí)現(xiàn)等比例不失真縮放的

下一篇：php筆記之-數(shù)據(jù)類型與常量的使用分析