Microsoft Office Access是由微軟發布的關系數據庫管理系統。它結合了 MicrosoftJet Database Engine 和 圖形用戶界面兩項特點，是 Microsoft Office 的系統程序之一。Microsoft Office Access是微軟把數據庫引擎的圖形用戶界面和軟件開發工具結合在一起的一個數據庫管理系統。它是微軟OFFICE的一個成員, 在包括專業版和更高版本的office版本里面被單獨出售。2018年9月25日,最新的微軟Office Access 2019在微軟Office 2019里發布。
using system;
using system.collections.generic;
using system.text;
/// <summary>
/// 構造分頁后的sql語句
/// </summary>
public static class paginghelper
{
/// <summary>
/// 獲取分頁sql語句，排序字段需要構成唯一記錄
/// </summary>
/// <param name="_recordcount">記錄總數</param>
/// <param name="_pagesize">每頁記錄數</param>
/// <param name="_pageindex">當前頁數</param>
/// <param name="_safesql">sql查詢語句</param>
/// <param name="_orderfield">排序字段，多個則用“,”隔開</param>
/// <returns>分頁sql語句</returns>
public static string createpagingsql(int _recordcount, int _pagesize, int _pageindex, string _safesql, string _orderfield)
{
//重新組合排序字段，防止有錯誤
string[] arrstrorders = _orderfield.split(new char[] { ',' }, stringsplitoptions.removeemptyentries);
stringbuilder sboriginalorder = new stringbuilder(); //原排序字段
stringbuilder sbreverseo教程rder = new stringbuilder(); //與原排序字段相反，用于分頁
for (int i = 0; i < arrstrorders.length; i++)
{
arrstrorders[i] = arrstrorders[i].trim(); //去除前后空格
if (i != 0)
{
sboriginalorder.append(", ");
sbreverseorder.append(", ");
}
sboriginalorder.append(arrstrorders[i]);
int index = arrstrorders[i].indexof(" "); //判斷是否有升降標識
if (index > 0)
{
//替換升降標識，分頁所需
bool flag = arrstrorders[i].indexof(" desc", stringcomparison.ordinalignorecase) != -1;
sbreverseorder.appendformat("{0} {1}", arrstrorders[i].remove(index), flag ? "asc" : "desc");
}
else
{
sbreverseorder.appendformat("{0} desc", arrstrorders[i]);
}
}
//計算總頁數
_pagesize = _pagesize == 0 ? _recordcount : _pagesize;
int pagecount = (_recordcount + _pagesize - 1) / _pagesize;
//檢查當前頁數
if (_pageindex < 1)
{
_pageindex = 1;
}
else if (_pageindex > pagecount)
{
_pageindex = pagecount;
}
stringbuilder sbsql = new stringbuilder();
//第一頁時，直接使用top n，而不進行分頁查詢
if (_pageindex == 1)
{
sbsql.appendformat(" select top {0} * ", _pagesize);
sbsql.appendformat(" from ({0}) as t ", _safesql);
sbsql.appendformat(" order by {0} ", sboriginalorder.tostring());
}
//最后一頁時，減少一個top n
else if (_pageindex == pagecount)
{
sbsql.append(" select * from ");
sbsql.append(" ( ");
sbsql.appendformat(" select top {0} * ", _recordcount - _pagesize * (_pageindex - 1));
sbsql.appendformat(" from ({0}) as t ", _safesql);
sbsql.appendformat(" order by {0} ", sbreverseorder.tostring());
sbsql.append(" ) as t ");
sbsql.appendformat(" order by {0} ", sboriginalorder.tostring());
}
//前半頁數時的分頁
else if (_pageindex < (pagecount / 2 + pagecount % 2))
{
sbsql.append(" select * from ");
sbsql.append(" ( ");
sbsql.appendformat(" select top {0} * from ", _pagesize);
sbsql.append(" ( ");
sbsql.appendformat(" select top {0} * ", _pagesize * _pageindex);
sbsql.appendformat(" from ({0}) as t ", _safesql);
sbsql.appendformat(" order by {0} ", sboriginalorder.tostring());
sbsql.append(" ) as t ");
sbsql.appendformat(" order by {0} ", sbreverseorder.tostring());
sbsql.append(" ) as t ");
sbsql.appendformat(" order by {0} ", sboriginalorder.tostring());
}
//后半頁數時的分頁
else
{
sbsql.appendformat(" select top {0} * from ", _pagesize);
sbsql.append(" ( ");
sbsql.appendformat(" select top {0} * ", ((_recordcount % _pagesize) + _pagesize * (pagecount - _pageindex)));
sbsql.appendformat(" from ({0}) as t ", _safesql);
sbsql.appendformat(" order by {0} ", sbreverseorder.tostring());
sbsql.append(" ) as t ");
sbsql.appendformat(" order by {0} ", sboriginalorder.tostring());
}
return sbsql.tostring();
}
/// <summary>
/// 獲取記錄總數sql語句
/// </summary>
/// <param name="_n">限定記錄數</param>
/// <param name="_safesql">sql查詢語句</param>
/// <returns>記錄總數sql語句</returns>
public static string createtopnsql(int _n, string _safesql)
{
return string.format(" select top {0} * from ({1}) as t ", _n, _safesql);
}
/// <summary>
/// 獲取記錄總數sql語句
/// </summary>
/// <param name="_safesql">sql查詢語句</param>
/// <returns>記錄總數sql語句</returns>
public static string createcountingsql(string _safesql)
{
return string.format(" select count(1) as recordcount from ({0}) as t ", _safesql);
}
}
