依然是Result consisted of more than one row，我要哭了

错误出现在这段代码里面，这是一个存储过程的片段，这段注释掉就不会错，但我还要这功能呢，求大神解答。
SQL code

IF ClassID=-1 THEN
      begin
        DECLARE  X int;
        DECLARE done int;
        DECLARE t_cursor cursor for SELECT ID From TopWinCMS_Class where ParentID=0 and IsShowInIndex=1 and 
LinkUrl =N'' and `ModelID` = ModelID order by `RootID` limit 1;
        declare continue handler FOR NOT FOUND SET done = 1; 
        SET @SQL='';
        SET done = 0;
        open t_cursor;
        while done = 0 do
        begin
            fetch  t_cursor into X;
            SET @SQL=concat('select ID,ModelID,ClassID,ClassName,ContentTitle,Hits,'''' as Content,ColorStyle,FontStyle,UpdateTime,TemplateFileName from VW_',TableName,' where deleted=0 and Pass=1 and ClassID in (',Get_ClassIDs(X),') limit ',TOP); 
            PREPARE stmt1 FROM @SQL;
            EXECUTE stmt1; 
            DEALLOCATE PREPARE stmt1;
        end;
        end while;
        close t_cursor;
    end;
END IF;

Get_ClassIDs(X)
代码如下
C# code

delimiter $$
drop function if exists Get_ClassIDs;
CREATE FUNCTION Get_ClassIDs(iid int)   
RETURNS VARCHAR(8000)
BEGIN
DECLARE IDs VARCHAR(255);
DECLARE PPt VARCHAR(255);
Select concat(`Path`,'%') into PPt FROM TopWinCMS_Class where `ID`=iid;
set @IDs='';
select concat(@IDs,`ID`,',') into @IDs from TopWinCMS_Class where Path Like  PPt;
IF LENGTH(@IDs)>0 THEN
 set @IDs=left(@IDs,lenth(@IDs)-1);
ELSE
 set @IDs='0';
end if;
return @IDs;
end$$

Select concat(`Path`,'%') into PPt FROM TopWinCMS_Class where `ID`=iid;
select concat(@IDs,`ID`,',') into @IDs from TopWinCMS_Class where Path Like PPt;

检查这两句的返回，估计是多条记录了。