sql - 递归update

 declare
   v_rlt number(8):=3;
   l_sql varchar2(300);        -- variable that contains a query
   l_c   sys_refcursor;        -- cursor variable(weak cursor).
   l_res1 VARCHAR2(30 BYTE);   -- variable containing fetching data
   l_res2 date;   -- variable containing fetching data
   l_res3 date;   -- variable containing fetching data
begin
    <<while_loop>>
    while(v_rlt > 0)
    loop
         l_sql := 'SELECT GUID, MIN(LAST_UPDT_DATE_TIME_STAMP),MAX(LAST_UPDT_DATE_TIME_STAMP) FROM XX WHERE XX';
         open l_c for l_sql;
         loop
         fetch l_c into l_res1,l_res2, l_res3;
         exit when l_c%notfound;   -- Exit the loop if there is nothing to fetch.
         if(l_res2 < l_res3) then
            UPDATE XX;end if;
        if(l_res2 = l_res3) then
            UPDATE XX;end if;
         COMMIT;
        -- process fetched data
         end loop;
        close l_c; -- close the cursor
      SELECT COUNT(*) into v_rlt from (XX);
    end loop while_loop;
      dbms_output.put_line('WHILE finished');
end;
/
COMMIT;