首先在shop admin下的shop_conadd.php里面添加如下代码：

  <tr> \r\n      <td height=\"30\" width=\"100\" align=\"right\" >";
echo "产品分类2";
echo "</td>\r\n      <td width=\"5\" >&nbsp;</td>\r\n      <td height=\"30\" > \r\n        ";
echo "<s";
echo "elect id=\"selcatid2\" name=\"catid2\" >\r\n          ";
$fsql->query( "select * from {P}_shop_cat  order by catpath" );
while ( $fsql->next_record( ) )
{
  $lpid = $fsql->f( "pid" );
  $lcatid = $fsql->f( "catid" );
  $cat = $fsql->f( "cat" );
  $catpath = $fsql->f( "catpath" );
  $lcatpath = explode( ":", $catpath );
  $i = 0;
  for ( ; $i < sizeof( $lcatpath ) - 2; $i++ )
  {
    $tsql->query( "select catid,cat from {P}_shop_cat where catid='{$lcatpath[$i]}'" );
    if ( $tsql->next_record( ) )
    {
      $ncatid = $tsql->f( "cat" );
      $ncat = $tsql->f( "cat" );
      $ppcat .= $ncat."/";
    }
  }
  if ( $pid == $lcatid )
  {
    echo "<option value='".$lcatid."' selected>".$ppcat.$cat."</option>";
  }
  else
  {
    echo "<option value='".$lcatid."'>".$ppcat.$cat."</option>";
  }
  $ppcat = "";
}
echo " \r\n\t\t</select>\r\n\t\t</td>\r\n    </tr>\r\n\t  

其次，保存的时候进行处理：

 $catid2 = $_POST['catid2'];

    $msql->query( "select catpath from {P}_shop_cat where catid='{$catid2}'" );
  if ( $msql->next_record( ) )
  {
    $catpath2 = $msql->f( "catpath" );
  }

吧catid2 与catpath2 放到prop17 prop18列

shop_conmod.php的时候，在进行相应的处理

在 model下的 list  query 进行如下处理

 //显示分类规则:如果后台不指定分类,则显示当前所在分类,否则不限分类

  if($catid!=0 && $catid!=""){
   $catid=fmpath($catid);
   $scl.=" and (catpath regexp '$catid' or prop18 regexp '$catid' ) ";
  }elseif($nowcatid!=0 && $nowcatid!=""){
   $catid=fmpath($nowcatid);
  $scl.=" and (catpath regexp '$catid' or prop18 regexp '$catid' ) ";
  }