ASP.NET 2.0中随机读取Access数据库记录_[Asp.Net教程]
					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#:
<%@ Page Language="C#" %>
 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;
 }
 随机读取Access数据库记录
 
VB.NET:
<%@ Page Language="VB" Debug="true" %>
 Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
 Dim TimeString As String = DateTime.Now.Ticks.ToString()
 Dim a As UInt32 = UInt32.Parse(TimeString.Substring(TimeString.Length - 8, 8))
 Dim b As Int32 = BitConverter.ToInt32(BitConverter.GetBytes(a), 0)
 Dim rnd As Random = New Random(b)
 Dim intRandomNumber As Integer = rnd.Next
 Response.Write(intRandomNumber)
 Dim ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\aspxWeb.mdb;Persist Security Info=True"
 Dim sql As String = "select top 10 Title,objectGuid from Document Order By Rnd(" + (-1 * intRandomNumber).ToString() + "*id)"
 Dim cn As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection(ConnectionString)
 cn.Open()
 Dim cmd As System.Data.OleDb.OleDbCommand = New System.Data.OleDb.OleDbCommand(sql, cn)
 Dim dr As System.Data.OleDb.OleDbDataReader = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
 GridView1.DataSource = dr
 GridView1.DataBind()
 dr.Close()
 cmd.Dispose()
 cn.Dispose()
 cn = Nothing
 End Sub
 随机读取Access数据库记录
 
来源:孟宪会之精彩世界