sql百万级数据通用分页类asp.net版

最新推荐文章于 2018-04-15 15:44:04 发布

原创最新推荐文章于 2018-04-15 15:44:04 发布 · 1.9k 阅读

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#sql #asp.net #dataset #string #asp #object

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本文介绍了一种基于SQL的高效分页查询方法，通过构造特定的SQL语句实现快速分页，适用于大型数据库。文中提供了详细的代码实现及ASP.NET Web窗体应用示例。

using System;
using System.Data;
using System.Data.SqlClient;

namespace Pagination.Class
{
/// <summary>
/// Pager 的摘要说明。
/// </summary>
public class Pager
{
  public Pager()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //
  }
  /// <param name="fieldlist"></param>字段列表，如id,title,content
  /// <param name="condition"></param>条件，如id<100
  /// <param name="pkey"></param>主键，自增
  /// <param name="tablename"></param>表的名字，如News
  /// <param name="sort"></param>排序，0表示降序，1表示升序
  /// <param name="pagesize"></param>每页大小
  /// <param name="cpage"></param>当前页码
  public DataSet GetCurrentDataSet(string fieldlist,string condition,string pkey,string tablename,int sort,int pagesize,int cpage)//得到当前页记录
  {
   SqlConnection conn=new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["cs"]);
   SqlDataAdapter cmd=new SqlDataAdapter(GetSql(fieldlist,condition,pkey,tablename,sort,pagesize,cpage),conn);
   DataSet ds=new DataSet();
   cmd.Fill(ds);
   return ds;
  }
  static string GetSql(string fieldlist,string condition,string pkey,string tablename,int sort,int pagesize,int cpage)
  {
   string sql="";
   if(sort==0)
   {
    if(condition!="")
    {
     sql="select top "+pagesize.ToString()+" "+fieldlist+" from "+tablename+" where "+condition+" and "+pkey+" not in(select top "+pagesize*(cpage-1)+" "+pkey+" from "+tablename+" where "+condition+" and order by "+pkey+" desc) order by "+pkey+" desc";
    }
    else
    {
     sql="select top "+pagesize.ToString()+" "+fieldlist+" from "+tablename+" where "+pkey+" not in(select top "+pagesize*(cpage-1)+" "+pkey+" from "+tablename+" order by "+pkey+" desc) order by "+pkey+" desc";
    }
   }
   else
   {
    if(condition!="")
    {
     sql="select top "+pagesize.ToString()+" "+fieldlist+" from "+tablename+" where "+condition+" and "+pkey+" not in(select top "+pagesize*(cpage-1)+" "+pkey+" from "+tablename+" where "+condition+" and order by "+pkey+" asc) order by "+pkey+" asc";
    }
    else
    {
     sql="select top "+pagesize.ToString()+" "+fieldlist+" from "+tablename+" where "+pkey+" not in(select top "+pagesize*(cpage-1)+" "+pkey+" from "+tablename+" order by "+pkey+" asc) order by "+pkey+" asc";
    }
   }
   return sql;
  }
  public int GetCounts(string pkey,string tablename,string condition)//得到总记录数
  {
   string sql;
    if(condition!="")
    {
        sql="select count("+pkey+") from "+tablename where "+condition;
    }
    else
    {
        sql="select count("+pkey+") from "+tablename;
    }
   SqlConnection conn=new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["cs"]);
   SqlCommand cmd=new SqlCommand(sql,conn);
   conn.Open();
   SqlDataReader dr=cmd.ExecuteReader(CommandBehavior.CloseConnection);
   dr.Read();
   string str=dr[0].ToString();
   dr.Close();
   return Convert.ToInt32(str);
  }
}
}
这里可以输出总记录数和当前页面的dataset。

针对此通用分页类的调用实例
1 建表News
CREATE TABLE [News] (
[id] [int] IDENTITY (1, 1) NOT NULL ,
[title] [nvarchar] (100) COLLATE Chinese_PRC_CI_AS NULL ,
[content] [text] COLLATE Chinese_PRC_CI_AS NULL ,
CONSTRAINT [PK_News] PRIMARY KEY CLUSTERED
(
  [id]
) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
2 建立生成数据的存储过程
create proc addnews
@count int
as
declare @i int
set @i=0
set nocount on
while @i<@count
begin
set @i=@i+1
insert into news (title,content) values ('百万级数据分页测试','Test by 逐日★风')
end
set nocount off
GO
3 生成数据
addnews 2000000

4 建立Aspx文件
<asp:Repeater id="Repeater1" runat="server">
<HeaderTemplate>
  <table width="800" border="1" cellpadding="3">
</HeaderTemplate>
<ItemTemplate>
  <tr>
   <td><%#DataBinder.Eval(Container.DataItem,"id")%></td>
   <td><%#DataBinder.Eval(Container.DataItem,"title")%></td>
   <td><%#DataBinder.Eval(Container.DataItem,"content")%></td>
  </tr>
</ItemTemplate>
<FooterTemplate>
  </table>
</FooterTemplate>
</asp:Repeater>
<div align="center"><FONT face="宋体">共</FONT>
<asp:Label id="lblcount" runat="server"></asp:Label><FONT face="宋体">条记录，当前
  <asp:Label id="lblcurrent" runat="server"></asp:Label>页  
  <asp:LinkButton id="hlprev" runat="server">上页</asp:LinkButton> 
  <asp:LinkButton id="hlnext" runat="server">下页</asp:LinkButton>  
  <asp:DropDownList id="DropDownList1" runat="server" AutoPostBack="True"></asp:DropDownList></FONT></div>
5 Cs文件
protected System.Web.UI.WebControls.Label lblcount;
  protected System.Web.UI.WebControls.Label lblcurrent;
  protected System.Web.UI.WebControls.DropDownList DropDownList1;
  protected System.Web.UI.WebControls.LinkButton hlprev;
  protected System.Web.UI.WebControls.LinkButton hlnext;
  protected System.Web.UI.WebControls.Repeater Repeater1;
  private int pagesize=20;
  static int cpage;
  static int TotalPages;

  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面
   if(!this.IsPostBack)
   {
    cpage=1;
    Class.Pager pg=new Class.Pager();
    int Counts=pg.GetCounts("id","News","");
    lblcount.Text=Counts.ToString();//得到总记录数

    TotalPages=Counts/pagesize;
    if(Counts<pagesize)
     TotalPages=1;
    else
    {
     if(Counts%pagesize!=0)TotalPages++;
    }//计算总页数

    lblcurrent.Text=cpage.ToString()+"/"+TotalPages;

    DataSet ds=new DataSet();
    ds=pg.GetCurrentDataSet("id,title,content","","id","News",1,10,cpage);

    bind(ds);
    Gethl();
    Getddlist();
   }
  }
  private void Getddlist()
  {
   if(TotalPages!=1)
   {
    for(int i=1;i<=TotalPages;i++)
    {
     DropDownList1.Items.Add(new ListItem(i.ToString(),i.ToString()));
    }
   }
   else
   {
    DropDownList1.Items.Add(new ListItem("1","1"));
   }
  }
  private void Gethl()//得到上页，下页状态
  {
   if(lblcurrent.Text=="1")
   {
    hlprev.Enabled=false;
    hlnext.Enabled=false;
   }
   else
   {
    if(cpage==1)
     hlprev.Enabled=false;
    else
     hlprev.Enabled=true;
    if(cpage==Convert.ToInt32(TotalPages))
     hlnext.Enabled=false;
    else
     hlnext.Enabled=true;
   }
   lblcurrent.Text=cpage.ToString()+"/"+TotalPages;
  }
  private void bind(DataSet ds)
  {
   Repeater1.DataSource=ds;
   Repeater1.DataBind();
  }
  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }

  /// <summary>
  ///  设计器支持所需的方法 - 不要使用代码编辑器
  ///  修改此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
   this.hlprev.Click += new System.EventHandler(this.hlprev_Click);
   this.hlnext.Click += new System.EventHandler(this.hlnext_Click);
   this.DropDownList1.SelectedIndexChanged += new System.EventHandler(this.DropDownList1_SelectedIndexChanged);
   this.Load += new System.EventHandler(this.Page_Load);

}
#endregion

  private void hlprev_Click(object sender, System.EventArgs e)
  {
   cpage=cpage-1;
   Class.Pager pg=new Class.Pager();
   DataSet ds=new DataSet();
   ds=pg.GetCurrentDataSet("id,title,content","","id","News",cpage,10,cpage);
   bind(ds);
   Gethl();
   DropDownList1.ClearSelection();
   DropDownList1.Items.FindByValue(cpage.ToString()).Selected=true;
  }

  private void hlnext_Click(object sender, System.EventArgs e)
  {
   cpage=cpage+1;
   Class.Pager pg=new Class.Pager();
   DataSet ds=new DataSet();
   ds=pg.GetCurrentDataSet("id,title,content","","id","News",cpage,10,cpage);
   bind(ds);
   Gethl();
   DropDownList1.ClearSelection();
   DropDownList1.Items.FindByValue(cpage.ToString()).Selected=true;
  }
  private void DropDownList1_SelectedIndexChanged(object sender, System.EventArgs e)
  {
   cpage=Convert.ToInt32(DropDownList1.SelectedValue);
   Class.Pager pg=new Class.Pager();
   DataSet ds=new DataSet();
   ds=pg.GetCurrentDataSet("id,title,content","","id","News",cpage,10,cpage);
   bind(ds);
   Gethl();
  }

本人机器Pentium M1.7G 480MDDRM ,可用物理内存70MB左右。200W数据平均分页时间0.5秒左右。