如何在Oracle中使用游标来实现多重循环

 
这篇文章，是最近在写一个项目中所用的存储过程，由于是第一次接触oracle，其间花费了许多功夫，才把功能实现！特记录下来，以供参考！
[color=blue]create or replace package PSH_GPRSSTREAMSTAT is[/color]
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-- Author : ADMINISTRATOR
-- Created : 2004-12-8 10:56:01
-- Purpose : GPRS流量统计状态
-- 统计GPRS流量
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type
C_Cur is ref cursor;
function Calcu_GPRSSTREAM return number;
end PSH_GPRSSTREAMSTAT;
-----------------------------------------------------------------------------
create or replace package body PSH_GPRSSTREAMSTAT is
function Calcu_GPRSSTREAM return number
is
c_IPPackHeadLen constant number := 40; -- 定义IP包头长度
CURSOR c_SPINFO is
select distinct spid from sh_spinfo where isactive = '0';

c_MDTINFO C_Cur ;
v_MDTINFO number;

v_UpTransContentLens number(20,0); -- 存放当前GPRS终端上传转发的信息内容长度
v_UpContentLens number(20,0);
v_UpTotalLens number(20,0); -- 累计GPRS终端上传的信息内容长度
v_DownContentLens number(20,0);
v_DownTotalLens number(20,0);
newID number(20,0);

begin
-- 初始化
select max(statid) into newID from sh_gprsstreamstat;
if (newID is null) then
newID := 1;
end if;

for v_SPINFO In c_SPINFO loop -- 首先获取SPID
-- 其次遍历出与当前SPID对应的所有MDT
open c_MDTINFo for select distinct mdtid from sh_mdtinfo where (isactive = '0') and (spid = v_SPINFO.spid);
loop
fetch c_MDTINFO into v_MDTINFO;
exit when c_MDTINFO%notfound;

v_UpContentLens := 0;
v_UpTransContentLens := 0;
v_UpTotalLens := 0;
v_DownContentLens := 0;
v_DownTotalLens := 0;
-- 下面两个select语句是用来获得GPRS终端上传的信息流量
select sum(length(content) + c_IPPackHeadLen) into v_UpContentLens from sh_gprsmdtupinfo where (MDTID = v_MDTINFO) and (spid = v_SPINFO.spid) ;
select sum(length(content) + c_IPPackHeadLen) into v_UpTransContentLens from sh_gprsmdttransinfo where (issuccess = '1') and (MDTID = v_MDTINFO) and (spid = v_SPINFO.spid) ;
if (v_UpContentLens is null) then
v_UpContentLens := 0;
end if;
if (v_UpTransContentLens is null) then
v_UpTransContentLens := 0;
end if;
v_UpTotalLens := v_UpTotalLens + v_UpContentLens + v_UpTransContentLens;

-- 下面的Select语句是用来获得服务商下发的信息流量
select sum(length(content) + c_IPPackHeadLen) into v_DownContentLens from sh_gprsspdowninfo where (MDTID = v_MDTINFO) and (spid = v_SPINFO.spid) ;
if (v_DownContentLens is null) then
v_DownContentLens := 0;
end if;
v_DownTotalLens := v_DownTotalLens + v_DownContentLens ;

-- 将统计出的累计值存放到流量状态统计表中
if (v_UpTotalLens >0) or (v_DownTotalLens > 0) then
insert into sh_gprsstreamstat (statid,spid,mdtid,starttime,endtime,mdtupstream,spdownstream)
values(newID,v_SPINFO.spid,v_MDTINFO,sysdate,sysdate,v_UpTotalLens,v_DownTotalLens);
-- 自增量加1
newID := newID + 1;
end if;
end loop;
close c_MDTINFO;
commit;
end loop;
return 1;
end;

begin
null;
end PSH_GPRSSTREAMSTAT;