我在使用的分类信息的时候需要添加联动属性，结果去添加联动属性的时候，发现只可以添加一级联动和三级联动。

二级联动无法添加了。

在自己的5.6的后台添加的时候，发现是可以的。估计又是5.7版本的bug了。

    于是分析了代码，和大家分享下解决的办法：
首先我们找到我们的模板源码下面的 dede/stepselect_main.php  这个文件，

将这段代码

else if($action=='addenum_save')
{
    if(empty($ename) || empty($egroup))
    {
         Showmsg("类别名称或组名称不能为空！","-1");
         exit();
    }
    if($issign == 1 || $topvalue == 0)
    {
        $enames = explode(',', $ename);
        foreach($enames as $ename)
        {
            $arr = $dsql->GetOne("SELECT * FROM `dede_sys_enum` WHERE egroup='$egroup' AND (evalue MOD 500)=0 ORDER BY disorder DESC ");
            if(!is_array($arr)) $disorder = $evalue = ($issign==1 ? 1 : 500);
            else $disorder = $evalue = $arr['disorder'] + ($issign==1 ? 1 : 500);
               
            $dsql->ExecuteNoneQuery("INSERT INTO `dede_sys_enum`(`ename`,`evalue`,`egroup`,`disorder`,`issign`)
                                    VALUES('$ename','$evalue','$egroup','$disorder','$issign'); ");
        }
        WriteEnumsCache($egroup);                                                         
        ShowMsg("成功添加枚举分类！".$dsql->GetError(), $ENV_GOBACK_URL);
        exit();
    } else if ($issign == 2 && $topvalue != 0)
    {
        $minid = $topvalue;
        $maxnum = 500; // 三级子类最多500个
        $enames = explode(',', $ename);
        foreach ($enames as $ename)
        {
            $arr = $dsql->GetOne("SELECT * FROM `dede_sys_enum` WHERE egroup='$egroup' AND evalue LIKE '$topvalue.%%%' ORDER BY evalue DESC ");
            if(!is_array($arr))
            {
                $disorder = $minid;
                $evalue = $minid.'.001';
            }
            else
            {
                $disorder = $minid;
                preg_match("#([0-9]{1,})\.([0-9]{1,})#", $arr['evalue'], $matchs);
                $addvalue = $matchs[2] + 1;
                $addvalue = sprintf("d", $addvalue);
                $evalue = $matchs[1].'.'.$addvalue;

}
            $sql = "INSERT INTO `dede_sys_enum`(`ename`,`evalue`,`egroup`,`disorder`,`issign`)
                                    VALUES('$ename','$evalue','$egroup','$disorder','$issign'); ";
            // echo $sql;exit;
            $dsql->ExecuteNoneQuery($sql);
        }
        // echo $minid;
        WriteEnumsCache($egroup);
        ShowMsg("成功添加枚举分类！", $ENV_GOBACK_URL);
        exit();
    } else {
        $minid = $topvalue;
        $maxid = $topvalue + 500;
        $enames = explode(',', $ename);
        foreach($enames as $ename)
        {
            $arr = $dsql->GetOne("SELECT * FROM `dede_sys_enum` WHERE egroup='$egroup' AND evalue>$minid AND evalue<$maxid ORDER BY evalue DESC ");
            if(!is_array($arr))
            {
                $disorder = $evalue = $minid+1;
            }
            else
            {
                $disorder = $arr['disorder']+1;
                $evalue = $arr['evalue']+1;
            }
            $dsql->ExecuteNoneQuery("INSERT INTO `dede_sys_enum`(`ename`,`evalue`,`egroup`,`disorder`,`issign`)
                          VALUES('$ename','$evalue','$egroup','$disorder','$issign'); ");
        }
        WriteEnumsCache($egroup);
        ShowMsg("成功添加枚举分类！", $ENV_GOBACK_URL);
        exit();
    }
}

 

替换为：

else if($action=='addenum_save')
{
   if(empty($ename) || empty($egroup)) {
      Showmsg("类别名称或组名称不能为空！","-1");
      exit();
   }
   if($issign==1 || $topvalue==0)
   {
       $enames = explode(',', $ename);
       foreach($enames as $ename)
       {
        $arr = $dsql->GetOne("Select * From `dede_sys_enum` where egroup='$egroup' And (evalue mod 500)=0 order by evalue desc ");
    
     if(!is_array($arr)) $disorder = $evalue = ($issign==1 ? 1 : 500);
     else $disorder = $evalue = $arr['disorder'] + ($issign==1 ? 1 : 500);
    
     $dsql->ExecuteNoneQuery("Insert into `dede_sys_enum`(`ename`,`evalue`,`egroup`,`disorder`,`issign`)
                                    values('$ename','$evalue','$egroup','$disorder','$issign'); ");
        }
        WriteEnumsCache($egroup);     

 ShowMsg("成功添加枚举分类！".$dsql->GetError(), $ENV_GOBACK_URL);
    exit();
  }
  else
  {
    $minid = $topvalue;
    $maxid = $topvalue + 500;
    $enames = explode(',', $ename);
       foreach($enames as $ename)
       {
     $arr = $dsql->GetOne("Select * From `dede_sys_enum` where egroup='$egroup' And evalue>$minid And evalue<$maxid order by evalue desc ");
     if(!is_array($arr))
     {
      $disorder = $evalue = $minid+1;
     }
     else
     {
      $disorder = $arr['disorder']+1;
      $evalue = $arr['evalue']+1;
     }
     $dsql->ExecuteNoneQuery("Insert into `dede_sys_enum`(`ename`,`evalue`,`egroup`,`disorder`,`issign`)
                                  values('$ename','$evalue','$egroup','$disorder','$issign'); ");
        }
        WriteEnumsCache($egroup);
    ShowMsg("成功添加枚举分类！", $ENV_GOBACK_URL);
    exit();
  }
}


然后保存，在系统后台更新系统缓存就可以了的。现在在后台的联动类别管理里面就可以增加二级选择了。