Sqlserver存储过程和C#分页类简化你的代码![转]
在最近的项目中，由于要用到自定义分页的功能，本人就在网上找了个存储过程。结合C#写了个分页类。由于本人第一次写文章。写得不好，大家不要扔鸡蛋。。
下面是存储过程（sqlserver2000下通过)
--最通用的分页存储过程 -- 获取指定页的数据 CREATE PROCEDURE Pagination @tblName varchar(255), -- 表名 @strGetFields varchar(1000) = '*', -- 需要返回的列 @fldName varchar(255)='', -- 排序的字段名 @PageSize int = 10, -- 页尺寸 @PageIndex int = 1, -- 页码 @doCount bit = 0, -- 返回记录总数, 非 0 值则返回 @OrderType bit = 0, -- 设置排序类型, 非 0 值则降序 @strWhere varchar(1500) = '' -- 查询条件 (注意: 不要加 where) AS declare @strSQL varchar(5000) -- 主语句 declare @strTmp varchar(110) -- 临时变量 declare @strOrder varchar(400) -- 排序类型 if @doCount != 0 begin if @strWhere !='' set @strSQL = 'select count(*) as Total from ['+ @tblName +'] where '+ @strWhere else set @strSQL = 'select count(*) as Total from ['+ @tblName +']' end --以上代码的意思是如果@doCount传递过来的不是0，就执行总数统计。以下的所有代码都 --是@doCount为0的情况 else begin if @OrderType != 0 begin set @strTmp = '<(select min' set @strOrder = ' order by ['+ @fldName +'] desc' --如果@OrderType不是0，就执行降序，这句很重要！ end else begin set @strTmp = '>(select max' set @strOrder = ' order by ['+ @fldName +'] asc' end if @PageIndex = 1 begin if @strWhere != '' set @strSQL = 'select top ' + str(@PageSize) +' '+@strGetFields+ ' from ['+ @tblName +'] where ' + @strWhere + ' ' + @strOrder else set @strSQL = 'select top ' + str(@PageSize) +' '+@strGetFields+ ' from ['+ @tblName +'] '+ @strOrder --如果是第一页就执行以上代码，这样会加快执行速度 end else begin --以下代码赋予了@strSQL以真正执行的SQL代码 set @strSQL = 'select top ' + str(@PageSize) +' '+@strGetFields+ ' from [' + @tblName +'] where [' + @fldName + ']' + @strTmp + '(['+ @fldName + ']) from (select top ' + str((@PageIndex-1)*@PageSize) + ' ['+ @fldName + '] from ['+ @tblName +']' + @strOrder + ') as tblTmp)'+ @strOrder if @strWhere != '' set @strSQL = 'select top ' + str(@PageSize) +' '+@strGetFields+ ' from ['+ @tblName +'] where [' + @fldName + ']' + @strTmp + '(['+ @fldName + ']) from (select top ' + str((@PageIndex-1)*@PageSize) + ' ['+ @fldName + '] from ['+ @tblName +'] where ' + @strWhere + ' ' + @strOrder + ') as tblTmp) and ' + @strWhere + ' ' + @strOrder end end exec ( @strSQL) GO
下面是C#的代码
using System.Data ; using System.Data.SqlClient ; using Microsoft.ApplicationBlocks.Data ; using System.Web ; using System.Web.UI ; namespace RssLayer.PageHelper 
{ 
/// <summary> 
/// 分页类PagerHelper 的摘要说明。 
/// </summary> public class PagerHelper { private string connectionString; public PagerHelper(string tblname,string sortname,bool docount,string connectionString) { this.tblName = tblname; this.fldName = sortname ; this.connectionString = connectionString ; this.docount = docount; } public PagerHelper(string tblname,bool docount, string strGetFields, string fldName,int pagesize, int pageindex,bool ordertype,string strwhere,string connectionString ) { this.tblName = tblname ; this.docount = docount ; this.strGetFields = strGetFields ; this.fldName = fldName; this.pagesize = pagesize ; this.pageindex = pageindex; this.ordertype = ordertype ; this.strwhere = strwhere ; this.connectionString = connectionString ; } /// <summary> /// 得到记录集的构造函数 /// </summary> /// <param name="tblname"></param> /// <param name="strwhere"></param> /// <param name="connectionString"></param> public PagerHelper(string tblname,string strwhere,string connectionString) { this.tblName = tblname; this.strwhere = strwhere ; this.docount = true; this.connectionString = connectionString ; } private string tblName; public string TblName { get{return tblName;} set{tblName =value;} } private string strGetFields="*"; public string StrGetFields { get{return strGetFields ;} set{strGetFields =value;} } private string fldName=string.Empty; public string FldName { get{return fldName ;} set{fldName =value;} } private int pagesize =10; public int PageSize { get{return pagesize ;} set{pagesize =value;} } private int pageindex =1; public int PageIndex { get{return pageindex ;} set{pageindex =value;} } private bool docount=false; public bool DoCount { get{return docount ;} set{docount =value;} } private bool ordertype=false; public bool OrderType { get{return ordertype ;} set{ordertype =value;} } private string strwhere=string.Empty ; public string StrWhere { get{return strwhere ;} set{strwhere =value;} } public IDataReader GetDataReader() { if(this.docount) { throw new ArgumentException("要返回记录集，DoCount属性一定为false"); } // System.Web.HttpContext.Current.Response.Write(pageindex); return SqlHelper.ExecuteReader(connectionString,CommandType.StoredProcedure,"Pagination", new SqlParameter("@tblName",this.tblName), new SqlParameter("@strGetFields",this.strGetFields), new SqlParameter("@fldName",this.fldName), new SqlParameter("@PageSize",this.pagesize), new SqlParameter("@PageIndex",this.pageindex), new SqlParameter("@doCount",this.docount), new SqlParameter("@OrderType",this.ordertype), new SqlParameter("@strWhere",this.strwhere) ); } public DataSet GetDataSet() { if(this.docount) { throw new ArgumentException("要返回记录集，DoCount属性一定为false"); } return SqlHelper.ExecuteDataset(connectionString,CommandType.StoredProcedure,"Pagination", new SqlParameter("@tblName",this.tblName), new SqlParameter("@strGetFields",this.strGetFields), new SqlParameter("@fldName",this.fldName), new SqlParameter("@PageSize",this.pagesize), new SqlParameter("@PageIndex",this.pageindex), new SqlParameter("@doCount",this.docount), new SqlParameter("@OrderType",this.ordertype), new SqlParameter("@strWhere",this.strwhere) ); } public int GetCount() { if(!this.docount) { throw new ArgumentException("要返回总数统计，DoCount属性一定为true"); } return (int)SqlHelper.ExecuteScalar(connectionString,CommandType.StoredProcedure,"Pagination", new SqlParameter("@tblName",this.tblName), new SqlParameter("@strGetFields",this.strGetFields), new SqlParameter("@fldName",this.fldName), new SqlParameter("@PageSize",this.pagesize), new SqlParameter("@PageIndex",this.pageindex), new SqlParameter("@doCount",this.docount), new SqlParameter("@OrderType",this.ordertype), new SqlParameter("@strWhere",this.strwhere) ); } } 
}
如何调用？？？
假如我已经建立了2个类。一个是FavList数据库实体类，一个FavListCollection集合类。FavListCollection存储了FavList实体类的集合。
我可以这样写一个方法。
/// <summary> /// 返回FavList集合,使用存储过程自定义分页。 /// </summary> /// <param name="userid">数据库FavList的字段，用户ID</param> /// <param name="strwhere">查找的条件</param> /// <param name="ordertype">排序，true表示Desc,false表示asc</param> /// <param name="fldname">排序的字段，只能是一个字段</param> /// <param name="pagesize">每页的记录数</param> /// <param name="pageindex">到第几页的参数，由1开始。1表示第一页，以此类推。</param> /// <param name="recordcount">总记录数。</param> /// <returns></returns> public override FavListCollection GetFavListsByUser(int userid, string strwhere, bool ordertype, string fldname, int pagesize, int pageindex,out int recordcount ) { recordcount = 0; PagerHelper helper = new PagerHelper("Vfavlist",strwhere,ConnectionString); //VFavList是View recordcount = helper.GetCount(); PagerHelper helper2 = new PagerHelper("Vfavlist",false," * ",fldname, pagesize,pageindex,ordertype,strwhere,ConnectionString); IDataReader dr = helper2.GetDataReader(); FavListCollection list = new FavListCollection(); while(dr.Read()) { list.Add(PopulateFavList(dr)); } dr.Close(); return list; } DataGrid调用就不用说了吧。。
关于该分页的Bug和局限性
Bug：当排序那个字段内容相同的时候（例如：按时间来排序，而时间是一样的话。后面的记录会显示不出来。本人测试过)
局限性：排序只能一个字段，不能超过一个
