using System;
namespace CountryPark.DAL
{
/**//// <summary>
/// PageList 的摘要说明。
/// </summary>
public sealed class PageList
{
static PageList()
{
}
/**//// <summary>
/// 分页查询数据记录总数获取
/// </summary>
/// <param name="_tbName">----要显示的表或多个表的连接</param>
/// <param name="_ID">----主表的主键</param>
/// <param name="_strCondition">----查询条件,不需where</param>
/// <param name="_Dist">----是否添加查询字段的 DISTINCT 默认0不添加/1添加</param>
/// <returns></returns>
public static string getPageListCounts(string _tbName, string _ID, string _strCondition, int _Dist)
{
//---存放取得查询结果总数的查询语句
//---对含有DISTINCT的查询进行SQL构造
//---对含有DISTINCT的总数查询进行SQL构造
string strTmp="", SqlSelect="", SqlCounts="";
if (_Dist == 0)
{
SqlSelect = "SELECT ";
SqlCounts = "COUNT(*)";
}
else
{
SqlSelect = "SELECT DISTINCT ";
SqlCounts = "COUNT(DISTINCT "+ _ID +")";
}
if (_strCondition == string.Empty)
{
strTmp = SqlSelect +" @Counts="+ SqlCounts +" FROM "+ _tbName;
}
else
{
strTmp = SqlSelect +" @Counts="+ SqlCounts +" FROM "+ " WHERE (1=1) "+ _strCondition;
}
return strTmp;
}
/**//// <summary>
/// 获取分页数据查询SQL
/// </summary>
/// <param name="_tbName">----要显示的表或多个表的连接</param>
/// <param name="_fldName">----要显示的字段列表</param>
/// <param name="_PageSize">----每页显示的记录个数</param>
/// <param name="_Page">----要显示那一页的记录</param>
/// <param name="_PageCount">----查询结果分页后的总页数</param>
/// <param name="_Counts">----查询到的记录数</param>
/// <param name="_fldSort">----排序字段列表或条件(如果是多字段排列Sort指代最后一个排序字段的排列顺序(最后一个排序字段不加排序标记)--程序传参如：' SortA Asc,SortB Desc,SortC ')</param>
/// <param name="_Sort">----排序方法，0为升序，1为降序</param>
/// <param name="_strCondition">----查询条件,不需where</param>
/// <param name="_ID">----主表的主键</param>
/// <param name="_Dist">----是否添加查询字段的 DISTINCT 默认0不添加/1添加</param>
/// <returns></returns>
public static string getPageListSql(string _tbName, string _fldName, int _PageSize, int _Page, out int _PageCount, int _Counts, string _fldSort, int _Sort, string _strCondition, string _ID, int _Dist)
{
string strTmp=""; //---strTmp用于返回的SQL语句
string SqlSelect="", strSortType="", strFSortType="";
if (_Dist == 0)
{
SqlSelect = "SELECT ";
}
else
{
SqlSelect = "SELECT DISTINCT ";
}
if (_Sort == 0)
{
strFSortType = " ASC";
strSortType = " DESC";
}
else
{
strFSortType = " DESC";
strSortType = " ASC";
}
// ----取得查询结果总数量-----
int tmpCounts = 1;
if (_Counts != 0)
{
tmpCounts = _Counts;
}
// --取得分页总数
_PageCount = (tmpCounts + _PageSize - 1)/_PageSize;
// /**//**当前页大于总页数 取最后一页**/
if (_Page > _PageCount)
{
_Page = _PageCount;
}
if (_Page <= 0)
{
_Page = 1;
}
// --/*-----数据分页2分处理-------*/
int pageIndex = tmpCounts/_PageSize;
int lastCount = tmpCounts%_PageSize;
if (lastCount > 0)
{
pageIndex = pageIndex + 1;
}
else
{
lastCount = _PageSize;
}
if (_strCondition == string.Empty) // --没有设置显示条件
{
if (pageIndex < 2 || _Page <= (pageIndex/2 + pageIndex%2)) //--前半部分数据处理
{
if (_Page == 1)
{
strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +" ORDER BY "+ _fldSort +" "+ strFSortType;
}
else
{
strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +" WHERE "+ _ID +" <(SELECT MIN("+ _ID +") FROM ("+ SqlSelect +" TOP "+ _PageSize*(_Page-1) +" "+ _ID +" FROM "+ _tbName +
" ORDER BY "+ _fldSort +" "+ strFSortType +") AS TBMinID) ORDER BY "+ _fldSort +" "+ strFSortType;
}
}
else
{
_Page = pageIndex - _Page + 1; //后半部分数据处理
if (_Page <= 1) //--最后一页数据显示
{
strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ lastCount +" "+ _fldName +" FROM "+ _tbName +" ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB"+ " ORDER BY "+ _fldSort +" "+ strFSortType;
}
else
{
strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +
" WHERE "+ _ID +" >(SELECT MAX("+ _ID +") FROM("+ SqlSelect +" TOP "+ (_PageSize*(_Page-2)+lastCount) +" "+ _ID +" FROM "+ _tbName +
" ORDER BY "+ _fldSort +" "+ strSortType +") AS TBMaxID) ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB ORDER BY "+ _fldSort +" "+ strFSortType;
}
}
}
else // --有查询条件
{
if (pageIndex < 2 || _Page <=(pageIndex/2 + pageIndex%2))//--前半部分数据处理
{
if (_Page == 1)
{
strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +"WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strFSortType;
}
else
{
strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +
" WHERE "+ _ID +" <(SELECT MIN("+ _ID +") FROM ("+ SqlSelect +" TOP "+ (_PageSize*(_Page-1)) +" "+ _ID +" FROM " +_tbName +
" WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strFSortType +") AS TBMaxID) "+ _strCondition +
" ORDER BY "+ _fldSort +" "+ strFSortType;
}
}
else //--后半部分数据处理
{
_Page = pageIndex-_Page+1;
if (_Page <= 1) //--最后一页数据显示
{
strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ lastCount +" "+ _fldName +" FROM "+ _tbName +
" WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB ORDER BY "+ _fldSort +" "+ strFSortType;
}
else
{
strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +
" WHERE "+ _ID +" >(SELECT MAX("+ _ID +") FROM("+ SqlSelect +" TOP "+ (_PageSize*(_Page-2)+ lastCount) +" "+ _ID +" FROM "+ _tbName +
" WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strSortType +") AS TBMaxID) "+ _strCondition +
" ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB ORDER BY "+ _fldSort +" "+ strFSortType;
}
}
}
return strTmp;
}
}
}
--以上代码是针对之前写的TOP MAX模式的分页存储过程修改
--以上分页算法对SQL SERVER 和 ACCESS同样有效
参见:
http://www.cnblogs.com/hertcloud/archive/2005/12/21/301327.html