请大家帮忙,关于存储过程分页的问题...谢谢

drop procedure if exists prc_page_result;
create procedure prc_page_result (
in currpage int,
in columns varchar(500),
in tablename varchar(500),
in sCondition varchar(500),
in order_field varchar(100),
in asc_field int,
in primary_field varchar(100),
in pagesize int
)
begin
declare sTemp varchar(1000);
declare sSql varchar(4000);
declare sOrder varchar(1000);

if asc_field = 1 then
set sOrder = concat(' order by ', order_field, ' desc ');
set sTemp = '<(select min';
else
set sOrder = concat(' order by ', order_field, ' asc ');
set sTemp = '>(select max';
end if;

if currpage = 1 then
if sCondition <> '' then
set sSql = concat('select ', columns, ' from ', tablename, ' where ');
set sSql = concat(sSql, sCondition, sOrder, ' limit ?');
else
set sSql = concat('select ', columns, ' from ', tablename, sOrder, ' limit ?');
end if;
else
if sCondition <> '' then
set sSql = concat('select ', columns, ' from ', tablename);
set sSql = concat(sSql, ' where ', sCondition, ' and ', primary_field, sTemp);
set sSql = concat(sSql, '(', primary_field, ')', ' from (select ');
set sSql = concat(sSql, ' ', primary_field, ' from ', tablename, sOrder);
set sSql = concat(sSql, ' limit ', (currpage-1)*pagesize, ') as tabtemp)', sOrder);
set sSql = concat(sSql, ' limit ?');
else
set sSql = concat('select ', columns, ' from ', tablename);
set sSql = concat(sSql, ' where ', primary_field, sTemp);
set sSql = concat(sSql, '(', primary_field, ')', ' from (select ');
set sSql = concat(sSql, ' ', primary_field, ' from ', tablename, sOrder);
set sSql = concat(sSql, ' limit ', (currpage-1)*pagesize, ') as tabtemp)', sOrder);
set sSql = concat(sSql, ' limit ?');
end if;
end if;
set @iPageSize = pagesize;
set @sQuery = sSql;
prepare stmt from @sQuery;
execute stmt using @iPageSize;
end;

当不加条件时正常,但一加条件,第二页的第一条是从第一页的第二条开始...为什么?谢谢