%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

center>
h2>font face="宋體">訪問數(shù)據(jù)庫的通用代碼實(shí)例/font>
/h2>
/center>
body>
    form id="form1" runat="server">
    div>

    font face="宋體">
p align="center">1.請(qǐng)輸入相應(yīng)數(shù)據(jù)庫連接字符串/p>
p align="center">
asp:TextBox id="ConnStrTextBox" runat="server" Width="600">/asp:TextBox>
/p>
p align="center">2.請(qǐng)輸入相應(yīng)SQL查詢命令語句/p>
p align="center">
asp:TextBox id="SqlTextTextBox" runat="server" Width="600">/asp:TextBox>
/p>
p align="center">3.請(qǐng)選擇所連接的數(shù)據(jù)庫類型/p>
p align="center">
    asp:DropDownList ID="DBDropDownList" runat="server" Width="204px">
        asp:ListItem Selected="True">Access/asp:ListItem>
        asp:ListItem>SQLServer/asp:ListItem>
        asp:ListItem>Oracle/asp:ListItem>
        asp:ListItem>DB2/asp:ListItem>
    /asp:DropDownList>
/p>
p align="center">

asp:Button ID="Button1" runat="server" onclick="Button1_Click"  Text="通用數(shù)據(jù)庫連接代碼測(cè)試" />

/p>
p align="center">
asp:Label id="lblMessage" runat="server" Font-Bold="True" ForeColor="Red">/asp:Label>
/p>
    /form>
/font>
/div>

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //通用數(shù)據(jù)庫連接代碼，這里以連接Access數(shù)據(jù)庫為測(cè)試示例
        if (!IsPostBack)
        {
           ConnStrTextBox.Text = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=" + Server.MapPath("User.mdb");
           SqlTextTextBox.Text = "Select COUNT(*) From Info Where Name='小顧'";
            lblMessage.Text = "";
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {

        //定義數(shù)據(jù)庫連接字符串
        string MyConnectionString = this.ConnStrTextBox.Text;
        //定義查詢操作的SQL語句
        string MySQL = this.SqlTextTextBox.Text;
        //定義所要連接的數(shù)據(jù)庫類型為Access
        string MyType = this.DBDropDownList.SelectedValue;
        System.Data.IDbConnection MyConnection = null;
        // 根據(jù)數(shù)據(jù)庫類型，創(chuàng)建相應(yīng)的 Connection 對(duì)象
        switch (MyType)
        {
            //選擇的數(shù)據(jù)庫類型為“SQLServer”，創(chuàng)建SqlConnection類數(shù)據(jù)庫連接對(duì)象
            case "SQLServer":
                MyConnection = new System.Data.SqlClient.SqlConnection(MyConnectionString);
                break;
            case "Oracle":
                MyConnection = new System.Data.OracleClient.OracleConnection(MyConnectionString);
                break;
            //選擇的數(shù)據(jù)庫類型為“Access”，創(chuàng)建OleDbConnection類數(shù)據(jù)庫連接對(duì)象
            case "Access":
                MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;
            //選擇的數(shù)據(jù)庫類型為“DB2”，創(chuàng)建OleDbConnection類數(shù)據(jù)庫連接對(duì)象
            case "DB2":
                MyConnection = new System.Data.Odbc.OdbcConnection(MyConnectionString);
                break;
            default:
                MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;
        }
        Execute(MyConnection, MySQL);
    }
    public void Execute(System.Data.IDbConnection MyConnection, string strquery)
    {
        //使用 CreateCommand() 方法生成 Command 對(duì)象
        System.Data.IDbCommand MyCommand = MyConnection.CreateCommand();
        //執(zhí)行定義的SQL查詢語句
        MyCommand.CommandText = strquery;
        try
        {
            //打開數(shù)據(jù)庫連接
            MyConnection.Open();
            //定義查詢的結(jié)果信息
            String MyInfo = "測(cè)試連接成功！符合查詢要求的記錄共有：" + MyCommand.ExecuteScalar().ToString() + "條！";
            //輸出查詢結(jié)果信息
            lblMessage.Text = MyInfo;
        }
        catch (Exception ex)
        {
            //輸出錯(cuò)誤異常
            Response.Write(ex.ToString());
        }
        finally
        {
            //關(guān)閉數(shù)據(jù)庫連接
            MyConnection.Close();
        }
    }
}

//選擇的數(shù)據(jù)庫類型為“SQLServer”，創(chuàng)建SqlConnection類數(shù)據(jù)庫連接對(duì)象
case "SQLServer":
           MyConnection = new System.Data.SqlClient.SqlConnection(MyConnectionString);
                break;
case "Oracle":
           MyConnection = new System.Data.OracleClient.OracleConnection(MyConnectionString);
                break;
            //選擇的數(shù)據(jù)庫類型為“Access”，創(chuàng)建OleDbConnection類數(shù)據(jù)庫連接對(duì)象
case "Access":
           MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;
            //選擇的數(shù)據(jù)庫類型為“DB2”，創(chuàng)建OleDbConnection類數(shù)據(jù)庫連接對(duì)象
case "DB2":
           MyConnection = new System.Data.Odbc.OdbcConnection(MyConnectionString);
                break;
default:
            MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;