oracle数组，游标，case查询

create or replace procedure ttt  is
v_min varchar2(2);

type TYPE_CUR is ref cursor;
type type_array is table of varchar2(20);

v_cur TYPE_CUR ;
v_number varchar2(1);
var_array type_array:=type_array('s','x','X','0','1','2');

begin

       select case
               when min(substr(ID, 5)) = 'A' then
                '9'
               when min(substr(ID, 5)) = 'a' then
                'Z'
               when min(substr(ID, 5)) = '0' then
               '-1'
               else
                CHR(to_number(ASCII(NVL(min(substr(ID,5)), '0'))-1))
             end case
        into v_min
        from test;
       
        if v_min ='-1' then
          
           open v_cur for select to_char(nvl((substr("ID", 5)),0)) from test;
           loop
            fetch  v_cur into v_number;
                   exit when v_cur%notfound;
                FOR i IN 1..var_array.COUNT LOOP
                    if var_array(i)=v_number then
                       var_array.delete(i);
                       exit;
                    end if;
               
                 end loop;
    
            end loop;
            close v_cur;
            v_min:=var_array(var_array.FIRST);
        end if;
       
end ttt;