数据库操作指南：读取与写入

 //从数据库中删除
                string strdatasource = null;
                string strconnection = null;
                strdatasource = Application.StartupPath + @"\..\datasource\泉水.mdb";
                strconnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strdatasource;
                using (OleDbConnection thisconnection = new OleDbConnection(strconnection))
                {
                    //打开连接
                    thisconnection.Open();
                    //建立SQL命令
                    OleDbCommand thiscommand = thisconnection.CreateCommand();

                    thiscommand.CommandText = String.Format(" DELETE  From 泉水 WHERE ID='{0}'", strname);
                    thiscommand.ExecuteReader();
                    thisconnection.Close();
                }
  //写入数据库
                    string strdatasource = null;
                    string strconnection = null;
                    strdatasource = Application.StartupPath + @"\..\datasource\tree.mdb";
                    strconnection="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +strdatasource;
                    using (OleDbConnection thisconnection = new OleDbConnection(strconnection))
                    { 
                    //打开连接
                        thisconnection.Open();
                        //SQL命令
                        OleDbCommand thiscommand = thisconnection.CreateCommand();
                        //创建插入命令
                        thiscommand.CommandText =String.Format("INSERT INTO 古树(ID,class,address,age)VALUES('{0}','{1}','{2}','{3}')", this.id.Text, this.kind.Text, this.location.Text, this.age.Text);
                        OleDbDataReader thisreader = thiscommand.ExecuteReader();