DB2中通用的存储过程分页程序

   文章来源：    

CREATE PROCEDURE SALES.DB2PAGINATION(IN ITBNAME VARCHAR(2000),-- 表名
          IN ISHOWFIELD VARCHAR(1000),-- 显示字段
          IN IJOIN VARCHAR(1000),-- 联接条件（如：内联、外联）
          IN IWHERE VARCHAR(2000),-- 查询条件 (注意: 不要加 WHERE)
          IN IORDER VARCHAR(100),-- 排序条件 (注意: 不要加 ORDER BY)
          IN IPAGESIZE INTEGER,-- 页尺寸 如果为0 默认返回前一百万条数据可以认为是返回所有数据
         INOUT IOCURRENTPAGEIX INTEGER,-- 输入和输出：当前页
         OUT OPAGESTARTROW INTEGER,-- 输出：当前开始行
         OUT OPAGEENDROW INTEGER,-- 输出：当前结束行
         OUT OTOTALROWS INTEGER,-- 输出：当前总记录数
         OUT OHASPREVIOUSPAGE INTEGER,-- 输出：是否有上一页
         OUT OHASNEXTPAGE INTEGER,-- 输出：是否有下一页
         OUT OTOTALPAGES INTEGER,-- 输出：总页数
         OUT OERROR VARCHAR(100))-- 输出：错误信息
    RESULT SETS 1
    MODIFIES SQL DATA
    NOT DETERMINISTIC
    LANGUAGE SQL
BEGIN
/**//*----------------------------------------------------------------
 * Copyright (C) 2007  Huacius
 * 版权所有。
 *
 * 存储过程分页
 *
 *
//-----------------------------------------------------------------------*/
DECLARE STRSQL   VARCHAR(6000);-- 主语句

DECLARE result CURSOR WITH RETURN TO CALLER FOR S2;

DECLARE exit handler FOR sqlexception-- 异常捕获
BEGIN
set OERROR = 'error!';
END;

-- BODY start --
if(iwhere <> '') then
set iwhere = ' where ' || iwhere;
end if;
if(iorder <> '') then
set iorder = 'order by ' || iorder;
end if;
if(ijoin <> '') then
set ijoin = ' ' || ijoin;
end if;
  
set strsql = 'select count(*) from ' || itbname || ijoin || iwhere;
prepare s2 from strsql;
open result;
    fetch result into ototalrows;-- 总记录数
    close result;

if(ipagesize = 0) then
set ipagesize = 1000000;-- 每页显示数
end if;

set ototalpages = (ototalrows - 1) / ipagesize + 1;-- 总页数

if(iocurrentpageix < 1) then
set iocurrentpageix = 1;-- 当前页
else
if(iocurrentpageix > ototalpages) then
set iocurrentpageix = ototalpages;
end if;
end if;

set opagestartrow = ipagesize * (iocurrentpageix -1) + 1;-- 每页开始数
if(iocurrentpageix = ototalpages) then
set opageendrow = ototalrows;-- 每页结束数
else
set opageendrow = ipagesize * iocurrentpageix;
end if;

if(iocurrentpageix > 1) then
set ohaspreviouspage = 1;-- 是否有上一页
else
set ohaspreviouspage = 0;
end if;

if(iocurrentpageix < ototalpages) then
set ohasnextpage = 1;-- 是否有下一页
else
set ohasnextpage = 0;
end if;

set strsql = 'select * from (select rownumber() over(' || iorder || ') as rownum,'
|| ishowfield 
|| ' from '
|| itbname
|| ijoin
|| iwhere
|| ') as temp where rownum between ' || rtrim(char(opagestartrow)) || ' and ' || rtrim(char(opageendrow));
prepare s2 from strsql;
open result;
-- BODY end --

END