无限分类树操作

public static function getCategoryTree($id){
//$model=M('category');
if($id>0){
$obj=self::selectTable('category',array('id'=>$id),true);//$model->where(array('id'=>$id))->find();
if(!is_null($obj)){
$childList=self::selectTable('category',array('parent_id'=>$id));//$model->where(array('parent_id'=>$id))->select();
if(!is_null($childList)){
foreach($childList as $val){
$obj['childList'][]=self::getCategoryTree($val['id']);
}
}
}
if(isset($obj['childList'])){
//二维数组排序
usort($obj['childList'],function($a,$b){
$subtractRes=$a['order']-$b['order'];
if($subtractRes<0){
return 1;
}elseif($subtractRes>0){
return -1;
}else{
return 0;
}
});
}
return $obj;
}else{
$rootList=self::selectTable('category',array('parent_id'=>$id));//$model->where(array('parent_id'=>$id))->select();
if(!is_null($rootList)){
foreach($rootList as &$val){
$val=self::getCategoryTree($val['id']);
}
}
return $rootList;
}
}

//递归查找无限分类的父节点
public static function getCategoryParent($categoryId){
$category=self::selectTable('category',array('id'=>$categoryId),true);// M('category')->where(array('id'=>$categoryId))->find();
if(!empty($category)){$category['parent']=self::getCategoryParent($category['parent_id']);
}
return $category;
}

//从内存查询 表 以防止多次查库
private static function selectTable($tableName,array $where,$getFirst=false){
$res=array();
if(!isset(self::$tableData[$tableName])){
self::$tableData[$tableName]=M($tableName)->select();
}
if(false===self::$tableData[$tableName]){
return false;
}

is_null(self::$tableData[$tableName]) and self::$tableData[$tableName]=array();
foreach(self::$tableData[$tableName] as $val){
$flag=true;
foreach($where as $k=>$v){
if($val[$k]!=$v){
$flag=false;
break;
}
}
$flag and $res[]=$val;
}
$getFirst and $res=current($res);
empty($res) and $res=null;
return $res;
}