oracle变量问题

我在写一个存储过程。要求根据指标周期，以及规定的公式进行累计。create or replace procedure pr_dm_lcgl_distpctstat_1_sig(in_shenqing_year_month number)
is
/**********************************************************************
  *function   :
  *author     : 
  *createdate : 20120507
  *updatedate :
**********************************************************************/
        v_ex_code number;        v_gg_pct_jrcs_001 number(8,2);--T≤1
        v_gg_pct_jrcs_002 number(8,2);--1<T≤3
        v_gg_pct_jrcs_003 number(8,2);--3<T≤6
        v_gg_pct_jrcs_004 number(8,2);--6<T≤12
        v_gg_pct_jrcs_005 number(8,2);--t>12        v_seq_gg_pct_jrcs_001 number;
        v_seq_gg_pct_jrcs_002 number;
        v_seq_gg_pct_jrcs_003 number;
        v_seq_gg_pct_jrcs_004 number;
        v_seq_gg_pct_jrcs_005 number;
                     v_shenqing_year_month       number(6):=in_shenqing_year_month;
        v_shenqing_year             number(4):= in_shenqing_year_month/100;
        v_shenqing_month            number(2):= mod(in_shenqing_year_month,100);
        v_target                    varchar2(30);begin---获取指标
        
        for i in 5..8 loop
          v_target:='tar.pct_02_00'||i;
         
         select sum(decode(sign(v_target-30),1,1,0,1,-1,0)) as gg_pct_jrcs_001,
                sum(decode(sign(v_target-30),1,decode(sign(v_target-90),1,0,0,1,-1,1),0,0,-1,0)) as gg_pct_jrcs_002,
                sum(decode(sign(v_target-90),1,decode(sign(v_target-180),1,0,0,1,-1,1),0,0,-1,0)) as gg_pct_jrcs_003,
                sum(decode(sign(v_target-180),1,decode(sign(v_target-360),1,0,0,1,-1,1),0,0,-1,0)) as gg_pct_jrcs_004,
                sum(decode(sign(v_target-360),1,1,0,0,-1,0)) as gg_pct_jrcs_005
         
         into   v_gg_pct_jrcs_001,
                v_gg_pct_jrcs_002,
                v_gg_pct_jrcs_003,
                v_gg_pct_jrcs_004,
                v_gg_pct_jrcs_005 
         from   dm_sc_pct_target tar inner join dm_lcgl_distpctstat_index idx on tar.shenqingh=idx.shenqingh 
         where  idx.shenqing_year_month=v_shenqing_year_month;
         
         ---获取序列         select seq_dm_lcgl_distpctstat.nextval into v_seq_gg_pct_jrcs_001 from dual;
         select seq_dm_lcgl_distpctstat.nextval into v_seq_gg_pct_jrcs_002 from dual;
         select seq_dm_lcgl_distpctstat.nextval into v_seq_gg_pct_jrcs_003 from dual;
         select seq_dm_lcgl_distpctstat.nextval into v_seq_gg_pct_jrcs_004 from dual;
         select seq_dm_lcgl_distpctstat.nextval into v_seq_gg_pct_jrcs_005 from dual;---同步数据
         delete from dm_lcgl_distpctstat d where d.periodcode=v_target and d.year=v_shenqing_year and d.month=v_shenqing_month;         insert into dm_lcgl_distpctstat(id,periodcode,targetcode,year,month,factvalue,import_time)
         select v_seq_gg_pct_jrcs_001,v_target,'gg_pct_jrcs_001',v_shenqing_year,v_shenqing_month,v_gg_pct_jrcs_001,sysdate from dual
         union
         select v_seq_gg_pct_jrcs_002,v_target,'gg_pct_jrcs_002',v_shenqing_year,v_shenqing_month,v_gg_pct_jrcs_002,sysdate from dual
         union
         select v_seq_gg_pct_jrcs_003,v_target,'gg_pct_jrcs_003',v_shenqing_year,v_shenqing_month,v_gg_pct_jrcs_003,sysdate from dual
         union
         select v_seq_gg_pct_jrcs_004,v_target,'gg_pct_jrcs_004',v_shenqing_year,v_shenqing_month,v_gg_pct_jrcs_004,sysdate from dual
         union
         select v_seq_gg_pct_jrcs_005,v_target,'gg_pct_jrcs_005',v_shenqing_year,v_shenqing_month,v_gg_pct_jrcs_005,sysdate from dual;
--更新索引表
    update dm_lcgl_distpctstat_index idx
    set idx.status='1',
        idx.ex_code=0,
        idx.update_time=sysdate
        where  idx.shenqing_year_month=v_shenqing_year_month;
    commit;
     end loop;
exception
  
when others then
     rollback;
     v_ex_code:=sqlerrm;
     dbms_output.put_line(v_ex_code);
     update  dm_lcgl_distpctstat_index idx
     set idx.status='1',
        idx.ex_code=v_ex_code,
        idx.update_time=sysdate
        where  idx.shenqing_year_month=v_shenqing_year_month;
        dbms_output.put_line(v_sql);
     commit;end;
sign函数中的 v_target 原本应该是 pct_02_005 到 pct_02_008 我想用 FOR 循环的方式去替换 这样我就不用 写 很多SELECT 或者 写同样的 存储过程了。可是 实际上是不行的 。用过替换变量 可是重视要手动输入 。 希望高手解答 小弟感谢~