php 树型结构操作类代码

/***************************************************************
* 树型结构操作类(如果可以写成存储过程最理想)
*
*  ***************************************************************/

class treenode {
        var $f_id = 'id';
        var $f_pid = 'pid';
        var $f_lft = 'lft';
        var $f_rgt = 'rgt';
        var $f_s = 'sequence';
        var $f_level = 'lev';
        var $f_child_num = 'child_num';
        var $table;
        var $db;
        /**
         * 构造函数
         * @param string $table 表名
         * @param object $dbhanle adodb数据库教程操作句柄
         */
        function treenode($table, $dbhandle) {
                $this->db = $dbhandle;
                $this->table = $table;
                //$this->db->debug = true;
        }
        /**
         * 增加子节点
         * @param array $data 节点数据
         * @return bool
         */
        function addchild($data){
                $pid = $data[$this->f_pid];
                $sql = "select max({$this->f_s}) from {$this->table} where {$this->f_pid}=$pid";
                $data[$this->f_s] = $this->db->getone($sql) + 1;//得到待插入节点的序号
                $sql = "select * from {$this->table} where {$this->f_id} = -1";
                $rs = $this->db->execute($sql);
                $sql = $this->db->getinsertsql($rs, $data);
                $this->db->execute($sql); //插入节点数据
                if(!$this->db->affected_rows()){
                        return false;
                }
               
                $this->buildtree(1,1);        //重建节点左右值
                $this->updatelevel(1);        //生成节点级数值
                return true;
        }
        /**
         * 修改节点的数据
         * @param int $id 节点id号
         * @param array $data 节点数据
         * @return bool
         */

        function updatenode($id, $data) {
                //==>
                unset($data[$this->f_id]);
                unset($data[$this->f_pid]);
                unset($data[$this->f_lft]);
                unset($data[$this->f_rgt]);
                unset($data[$this->f_s]);
                unset($data[$this->f_level]);
                //<==防止直接修改节点之间的关系,因为可能会导致节点关系混乱
                $sql = "select * from ".$this->table." where {$this->f_id} = $id";
                $rs = $this->db->execute($sql);
                $sql = $this->db->getupdatesql($rs, $data);
                if (!$this->db->execute($sql)) {
                        return false;
                }
                return true;
        }
        /**
         * 删除节点
         * @param int $id 节点id号
         */
        function delnode($id) {
                $childnode = $this->getchild($id);
                $sql = "delete from {$this->table} where {$this->f_id} in($childnode)";
                $rs = $this->db->execute($sql); //把指定节点和其下的子节点一并删除,
                $this->buildtree(1,1);
        }
       
        /**
         * 移动节点位置
         * @param int $id 节点id号
         * @param string 'up'|string 'down' 移动方向,'up'或'down'
         * @param int $step 移动的步长
         */
        function movenode($id,$direction,$step=1){
                $sql = "select {$this->f_s},{$this->f_pid} from {$this->table} where {$this->f_id}=$id";
                $row = $this->db->getrow($sql);
                $pos = $row[$this->f_s];  //原次序
                $pid = $row[$this->f_pid];
                if('up' == $direction){
                        //计算新的次序值,(上移)
                        $pos_to = (($pos - $step)<1) ? 1 : $pos - $step;
                }
                else{
                        //计算新的次序值,(下移)
                        $sql = "select max({$this->f_s}) from {$this->table} where $this->f_pid = $pid";
                        $sequence_max = $this->db->getone($sql);
                        $pos_to = ($pos + $step)>$sequence_max ? $sequence_max : $pos + $step;
                }
                $sql = "update $this->table set $this->f_s = 0 where $this->f_id = $id";
                $rs = $this->db->execute($sql);
                $sql = "update {$this->table} set {$this->f_s} = $pos where {$this->f_pid} = $pid and {$this->f_s}=$pos_to";
                $rs = $this->db->execute($sql);
                $sql = "update {$this->table} set {$this->f_s}=$pos_to where {$this->f_id} = $id";
                $rs = $this->db->execute($sql);
                $this->buildtree(1,1);
        }
        /**
         * 重建指定节点的子节点的lft,rgt值
         * @param int $id 节点的id号
         * @param int $left 节点left值
         */
        function buildtree($id, $left) {
                $right = $left +1;
                $sql = "select $this->f_id from $this->table where $this->f_pid = $id order by $this->f_s asc";
                $rs = $this->db->execute($sql);
                while (!$rs->eof) {
                        $right = $this->buildtree($rs->fields[$this->f_id], $right);
                        $rs->movenext();
                }
                $sql  = "update $this->table set $this->f_lft = $left, $this->f_rgt = $right, $this->f_child_num = ($this->f_rgt-$this->f_lft-1)/2 where $this->f_id = $id";
                $this->db->execute($sql);
                return $right +1;
        }
       
        /**
         * 重新生成指定节点和其下的所有节点级数值
         */
        function updatelevel($id){
                $nodes = $this->getchild($id,false);
                $nodes[] = $id;
                foreach($nodes as $v){
                        $level = $this->getlevel($v);
                        $sql = "update $this->table set $this->f_level=$level where $this->f_id=$v";
                        $this->db->execute($sql);
                }
        }
        /**
         * 重新挂接节点
         * @param int $id 节点id号
         * @param int $to 要挂接到的节点id号
         */
        function remountnode($id,$to){
                $child = $this->getchild($id,false);
                if(!$this->db->getone("select count(*) from {$this->table} where {$this->f_id}=$to")){
                        core::raisemsg("错误!将要挂接到的节点'$to'不存在!");
                }
                if(in_array($to,$child)){
                        core::raisemsg("错误!挂接到的节点'$to'是待挂接节点'$id'的一个子节点!");
                }
                $sql = "select max($this->f_s) from ".$this->table." where pid = $to";
                $sequence = $this->db->getone($sql) + 1;
                $sql = "update {$this->table} set {$this->f_pid} = $to, {$this->f_s}=$sequence where {$this->f_id}=$id";
                $this->db->execute($sql);
                $this->buildtree(1,1);
                $this->updatelevel(1);
        }
       
        /**
         * 得到指定节点的级数
         * @param int $id 节点id号
         */
        function getlevel($id){
                $sql = "select count(*) from $this->table as c1,$this->table c2 where c1.$this->f_id = $id and c1.$this->f_lft between c2.$this->f_lft and c2.$this->f_rgt";
                return $this->db->getone($sql);
        }
        /**
         * 判断id号是否已存在
         */
        function isexist($id, $me = null) {
                $sql = "select ".$this->f_id." from ".$this->table." where ".$this->f_id."=$id";
                $another = $this->db->getone($sql);
                if (!strlen($another)) return false;
                else if ($another == $me) return false;
                else return true;
        }
        /**
         * 得到指定节点的所有子节点
         * @param int $id 节点id号
         * @param string $mode 返回的数据类型
         * 'str'为用','号连接的字串其它为数组
         */
        function getchild($id,$strmode = true){
                $sql = "select n1.$this->f_id as id from $this->table n1,$this->table n2 where n2.$this->f_id=$id and n1.$this->f_lft between n2.$this->f_lft and n2.$this->f_rgt";
                $rs = $this->db->execute($sql);
                while(!$rs->eof){
                        if($strmode)
                                $node .= $rs->fields[$this->f_id].',';
                        else $node[] = $rs->fields[$this->f_id];
                        $rs->movenext();
                }
                if($strmode){
                        $node = substr($node,0,-1);
                        if(strlen($node)){
                                return $node;
                        }
                        else return '0';
                }
                else return $node;
        }
}