1.下载ODBC.NET (FrameWork 2.0以上默认未安装)

2.创建项目，添加Microsoft.Data.ODBC.dll 引用

3.cs代码如下:

using System.Data;
using Microsoft.Data.Odbc;

4.连接代码示例:

SqlServer:

OdbcConnection cn;
        OdbcCommand cmd;
        string MyString;
        MyString="Select * from Customers";
        cn= new OdbcConnection("Driver={SQL Server};Server=mySQLServer;UID=sa;
                               PWD=myPassword;Database=Northwind;");
        cmd=new OdbcCommand(MyString,cn);
        cn.Open();
        MessageBox.Show("Connected");
        cn.Close();

OLEDB JET:

OdbcConnection cn;
        OdbcCommand cmd;
        string MyString;
        MyString="Select * from Titles";
        cn= new OdbcConnection("Driver={Microsoft Access Driver (*.mdb)};
            DBQ=D:\Program Files\Microsoft Office\Office10\Samples\Northwind.mdb;UID=;PWD=;");
              
        cmd=new OdbcCommand(MyString,cn);
        cn.Open();
        MessageBox.Show("Connected");
        cn.Close();

Oracle:

OdbcConnection cn;
       OdbcCommand cmd;
       string MyString;
       MyString="Select * from Customers";
       cn= new OdbcConnection("Driver={Microsoft ODBC for oracle};Server=myOracleServer;
                               UID=demo;PWD=demo;");
       cmd=new OdbcCommand(MyString,cn);
       cn.Open();
       MessageBox.Show("Connected");
       cn.Close();

DSN:

OdbcConnection cn;
       OdbcCommand cmd;
       string MyString;
       MyString="Select * from Customers";
       cn= new OdbcConnection("dsn=myDSN;UID=myUid;PWD=myPwd;");
       cmd=new OdbcCommand(MyString,cn);
       cn.Open();
       MessageBox.Show("Connected");
       cn.Close();