mysql 存储过程 分页 传入where

/*
--名称：MYSQL版查询分页存储过程 by peace 2013-8-14
--输入参数：@fields        -- 要查询的字段用逗号隔开
--输入参数：@tables        -- 要查询的表
--输入参数：@where        -- 查询条件
--输入参数：@orderby    -- 排序字段
--输出参数：@page        -- 当前页计数从1开始
--输出参数：@pagesize    -- 每页大小
--输出参数：@totalcount -- 总记录数
--输出参数：@pagecount  -- 总页数
*/
DROP PROCEDURE IF EXISTS Query_Pagination;
CREATE PROCEDURE Query_Pagination
(
    in _fields varchar(2000),  
    in _tables text,
    in _where varchar(2000), 
    in _orderby varchar(200),
    in _pageindex int,
    in _pagesize int,
    in _sumfields  varchar(200),/*增加统计字段2013-5-8 peaceli*/
    out _totalcount int ,
    out _pagecount int
)
begin
   set @startRow = _pageSize*(_pageIndex -1);
   set @pageSize = _pageSize;  set @rowindex = 0;
     set @strsql = CONCAT('select sql_calc_found_rows @rowindex:=@rowindex+1 as rownumber,',_fields,' from ',_tables,case ifnull(_where,'') when '' then '' else concat(' where ',_where) end,' order by ',_orderby,' limit ',@startRow,',',@pageSize);
     prepare strsql from @strsql;
     execute strsql;
   deallocate prepare strsql;
   set _totalcount = found_rows();

   if (_totalcount <= _pageSize) then
                    set _pagecount = 1;
                    else if (_totalcount % _pageSize > 0) then
                    set _pagecount = _totalcount / _pageSize + 1;
                    else
                     set _pagecount = _totalcount / _pageSize;
            end if;
        end if;
if(ifnull(_sumfields,'') <> '') then set @sumsql = contact('select ',_sumfields,' from ',_tables,case ifnull(_where,'') when '' then '' else concat(' where ',_where) end); prepare sumsql from @sumsql; execute sumsql; deallocate prepare sumsql; end if; end