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- oracle 分页过程超慢。直接SQL N快,咋回事
日期:2014-05-17 浏览次数:20903 次
oracle 分页过程超慢。直接SQL N快,怎么回事
包
create or replace package DB_Oper is
type ref_DataSet IS REF CURSOR;
function GetCount(mTableName varchar2, mTerm varchar2) return number;
procedure return_DataSet(
mTableName in varchar2, --表名
mTerm in varchar2, --条件
mPageSize in number, --每页显示记录数
mPageIndex in number, --当前页
mOrderField in varchar2, --排序字段
mOrderStyle in number, --排序方式 0 升序 1 降序
mTotalRecords out number, --总记录数
mDateSet out ref_DataSet --记录
);
end DB_Oper;
包体:
create or replace package body DB_Oper is
----- 获取记录数 ------
function GetCount(mTableName varchar2, mTerm varchar2) return number is
i number;
vSql varchar2(1000);
begin
i := 0;
vSql := 'select count(*) from ' || mTableName ;
if length(mTerm) > 0 then
vSql := vSql || ' where ' || mTerm;
end if;
execute IMMEDIATE vSql into i;
return(i);
end;
----- 数据分页 ----------
procedure return_DataSet(
mTableName in varchar2, --表名
mTerm in varchar2, --条件
mPageSize in number, --每页显示记录数
mPageIndex in number, --当前页
mOrderField in varchar2, --排序字段
mOrderStyle in number, --排序方式 0 升序 1 降序
mTotalRecords out number, --总记录数
mDateSet out ref_DataSet --记录集
) is
begin
declare
Invalid_Input Exception;
vSql varchar2(1000);
Start_page number;
End_page number;
n_PageIndex number;
n_PageSize number;
--mTotalRecords number;
begin
mTotalRecords := GetCount(trim(mTableName), trim(mTerm));
vSql := 'select * from ' || mTableName;
if length(trim(mTerm)) > 0 then
vSql := vSql || ' where ' || trim(mTerm) ;
end if;
if length(trim(mOrderField)) > 0 then
begin
vSql := vSql || ' order by ' || trim(mOrderField);
if morderStyle > 0 then
vSql := vSql || ' desc ';
end if;
end;
end if;
--
n_PageSize := mPageSize;
if mPageSize <= 0 then
n_PageSize := 10;
end if;
n_PageIndex := mPageIndex;
if mPageIndex <= 0 then
n_PageIndex := 1;
end if;
if mTotalRecords > 0 and n_PageIndex > 1 then
begin
--如果n_pageindex大于实际的页数,则取实际页数
if n_PageIndex > round((mTotalRecords / n_PageSize) + 0.5) then
n_PageIndex := round((mTotalRecords / n_PageSize) + 0.5);
end if;
end;
end if;
Start_page := (n_PageIndex - 1) * n_PageSize + 1;
End_page := n_PageIndex * n_PageSize;
vSql := 'SELECT * FROM (SELECT A.*, rownum r FROM ( ' || vSql || ' ) A WHERE rownum <= ' || End_page || ' ) B WHERE r >= '|| Start_page;
Open mDateSet for vSql;
exception
When Invalid_Input Then
open mDateSet for select null from dual;
end;
end return_DataSet;
end DB_Oper;
------解决方案--------------------