ASP.NET 2.0下随机读取Access记录的实现方法

2024-07-10 13:14:29

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由于使用ADO访问Access数据库会有缓存，这在随机提取数据库数据时，例如：sql="select top 10 Title,objectGuid from Document Order By Rnd(id)"，将得不到随机记录，下面的例子可以克服这一缺陷，实现数据库的随机读取。
C#：

复制代码代码如下:

	
	<%@ Page Language="C#" %> 
	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
	<script runat="server"> 
	protected void Page_Load( object sender, EventArgs e ) 
	{ 
	Random rnd = new Random(unchecked((int)DateTime.Now.Ticks)); 
	int intRandomNumber = rnd.Next(); 
	string ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=　DataDirectory　aspxWeb.mdb;Persist Security Info=True"; 
	string sql = "select top 10 Title,objectGuid from Document Order By Rnd(" + (-1 * intRandomNumber) + "*id)"; 
	System.Data.OleDb.OleDbConnection cn = new System.Data.OleDb.OleDbConnection(ConnectionString); 
	cn.Open(); 
	System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand(sql, cn); 
	System.Data.OleDb.OleDbDataReader dr = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection); 
	GridView1.DataSource = dr; 
	GridView1.DataBind(); 
	dr.Close(); 
	cmd.Dispose(); 
	cn.Dispose(); 
	cn = null; 
	} 
	</script> 