//1、添加引用 System.data.oracleClient
            //2、设置连接字符串  data source是服务名(也就是在客户端sqlplus中需要输入的主机字符串)
            //3、以下用法和sqlserver Access 用法一直
            string strConn = "data source=oamis;user=scott;password=tiger;";
            OracleConnection conn = new OracleConnection(strConn);
            conn.Open();
            OracleCommand cmd = new OracleCommand();
            cmd.CommandText = "select * from emp";
            cmd.Connection = conn;
            DataSet ds = new DataSet();
            OracleDataAdapter ad = new OracleDataAdapter(cmd);
            ad.Fill(ds);

现在机器上用sqlplus连接 然后在调用上面方法,sqlplus都连不进去,上面方法肯定不行