请教诸位高手 怎么做这段程序???

Question

为什么要建两个表呢？在一个表内就可以做出来了呀，一个产品类有一个父id，一个子id,从属关系即可确定。对应查找就可以了。

Answer 1

给你看看这个类表
CREATE TABLE `web_board` (
`boardid` tinyint(4) unsigned NOT NULL auto_increment,
`boardname` varchar(20) NOT NULL default '',
`boardnick` varchar(20) NOT NULL default '',
`p_b_id` tinyint(4) unsigned NOT NULL default '0',
UNIQUE KEY `boardid` (`boardid`,`boardname`)
) TYPE=MyISAM AUTO_INCREMENT=19 ;
可以用其他方式
文件tree.class.php
[PHP:--------------------------------------------------------------------------------
<?php 
class Tree {
    /*
    *$tree_t $tree_c $tree_l $tree_k够成树状结构的图形
    */
    var $tree_t="┝";//节点,下面还有同深度的节点
    var $tree_c="┕";//节点,下面还没有同深度的节点
    var $tree_l="│";//非节点,过渡,下面有父节点同深度的节点
    var $tree_k="&nbsp;&nbsp;";//非节点,过渡,下面没有父节点同深度的节点
    
    /*
    $tree_f,$tree_a和$tree_m 可以使用[treeid] [ptreeid] [treename] [treenick] [allvalue]
    四个字串代替相应的变量
    */
    var $tree_m="[treename]([treenick])";//主体
    var $tree_f="<option value=[treeid]>";//前缀    
    var $tree_a="</option>";//后缀
    
    /*$outstr 输出树状目录结构的字符串*/
    var $outstr;
    /*设定显示*/
    function setTree ($t,$c,$l,$k,$m,$f,$a){
        if (!empty($t)) {
            $this->tree_t=$t;
        }
        if (!empty($c)) {
            $this->tree_c=$c;
        }
        if (!empty($l)) {
            $this->tree_l=$l;
        }
        if (!empty($k)) {
            $this->tree_k=$k;
        }
        if (!empty($f)) {
            $this->tree_f=$f;
        }
        if (!empty($a)) {
            $this->tree_a=$a;
        }
        if (!empty($m)) {
            $this->tree_m=$m;
        }
    }
    /*检索表生成数组*/
    function _list_tree($table) {
        $query="select * from $table order by p_b_id";
        $result=mysql_query($query);
        while ($row=mysql_fetch_assoc($result)) {
            $arr_tree[$row["p_b_id"]][$row["boardid"]]=$row["p_b_id"]."|".$row["boardid"]."|".$row["boardname"]."|".$row["boardnick"];
        }
        return ($arr_tree);
    }
    /*
    *_echo_o_board($p_b_id,$arrboard,&$q_str,$i)
    *生成树状目录结构
    *$p_b_id 父目录id
    *$arrboard _list_board()生成的数组
    
    *$q_str数组 记录显示树状目录结构$tree_l和$tree_k的数组
    *$i深度
    *$kk同一层内的序号0开始
    *使用递归生成树状结构
    */
    function _echo_o_board($p_t_id,$arrtree,&$q_str,$i) {
        if (is_array($arrtree[$p_t_id])) {
            $len=count($arrtree[$p_t_id]);
            $kk=0;
            foreach($arrtree[$p_t_id] as $key=>$var) {
                list($ptreeid,$treeid,$treename,$treenick)=explode("|",$var);//分割数组信息
                /*
                生成结构
                */
                if ($kk<$len-1) {
                    $end_str=$this->tree_t;
                    $q_str[$i]=$this->tree_l;
                } else {
                    $end_str=$this->tree_c;
                    $q_str[$i]=$this->tree_k;
                }
                if ($p_t_id==0) {
                    //检索的是最顶层目录
                    $i=0;
                }
                $r_str=array("treeid"=>$treeid,"ptreeid"=>$ptreeid,"treename"=>$treename,"treenick"=>$treenick,"allvalue"=>$var);
                $this->outstr.=$this->_replace($this->tree_f,$r_str);
                for ($k=0;$k<$i;$k++) {
                    $this->outstr.=$q_str[$k];
                }
                $this->outstr.=$end_str;
                $this->outstr.=$this->_replace($this->tree_m,$r_str);
                $this->outstr.=$this->_replace($this->tree_a,$r_str);
                $i++;
                $this->_echo_o_board($key,$arrtree,&$q_str,$i);
                $kk++;//移到下一个
                $i--;//恢复$i
                /*
                生成结构完成
                */
            }
        } else {
            /*检索到最底层返回*/
            return;
        }
    }
    /*置换定义的字串*/
    function _replace($str,$r_str) {
        foreach ($r_str as $key=>$var) {
            $str=str_replace("[$key]",$var,$str);
        }
        return($str);
    }
    /*echo_tree()显示树状目录*/
    function echo_tree() {
        echo $this->outstr;
    }
    /*
    *list_select_tree()和list_tree()是两个默认的树状目录结构
    */
    function list_select_tree() {    
        $table=s_table_n("board");
        $arrboard=$this->_list_tree($table);
        $this->outstr="<select name=p_b_id class=boardsele>";
        $this->outstr.="<option value=0><--顶层板块--></option>";
        $this->_echo_o_board(0,$arrboard,$q_str,0);
        $this->outstr.="</select>";
        return ($outstr);
    }
    
    function list_tree() {
        $table=s_table_n("board");
        $arrboard=$this->_list_tree($table);
        $t="<img src=./images/tree_t.gif align=absmiddle  width=20 height=20>";
        $c="<img src=./images/tree_c.gif align=absmiddle  width=20 height=20>";
        $l="<img src=./images/tree_l.gif align=absmiddle  width=20 height=20>";
        $k="☆";//"<img src=./images/tree_k.gif align=absmiddle  width=20 height=20>";
        $m="<input type=\"radio\" name=\"board\" value=\"[allvalue]\"  width=20 height=20>[treename]([treenick])";
        $f="【★】";
        $a="<br>\n";
        $this->setTree ($t,$c,$l,$k,$m,$f,$a);
        $this->_echo_o_board(0,$arrboard,$q_str,0);
    }    
}?>