ADO.NET教程（2）实现增删查改

声明一个类，在类中实现增删查改的方法

 public class AdoNet
    {
        //声明连接字符串
        public string Sqlstr =  "data source={0};database={1};User id={2};pwd={3}";
        //声明ado类
        public SqlCommand Command;
        public SqlConnection Conn;
        //声明构造函数 传入连接字符串进行拼接
        public AdoNet(string datasource,string database, string userid,string pwd)
        {
            var cStr = string.Format(Sqlstr, datasource, database, userid, pwd);
             Conn = new SqlConnection(cStr);
        }
        //增加
        public void AdonetAdd(string cmd)
        {
            //打开数据库
            Conn.Open();
            //使用using 在命令执行完后会释放资源
            using (SqlCommand sqlcmd = new SqlCommand(cmd,Conn))
            {
               //获取要执行的sql语句
                sqlcmd.CommandText= cmd;
                if (sqlcmd.ExecuteNonQuery() > )
                {
                    Console.WriteLine("增加成功");
                }
                else
                {
                    Console.WriteLine("增加失败");
                }
            }
        }
        //删除
        public void AdoDelete(string cmd)
        {
            Conn.Open();
            using (SqlCommand sqlcmd = new SqlCommand(cmd, Conn))
            {
                sqlcmd.CommandText = cmd;
                if (sqlcmd.ExecuteNonQuery() > )
                {
                    Console.WriteLine("删除成功");
                }
                else
                {
                    Console.WriteLine("删除失败");
                }
            }
        }
        //查询
        public void AdoNetState(string cmd)
        {
            Conn.Open();
            Command = new SqlCommand(cmd, Conn);
            //批量查询
            SqlDataAdapter ad = new SqlDataAdapter(Command);
            DataTable dt = new DataTable();
            ad.Fill(dt);
            var s1= dt.Select();
            var arrlist1 = s1[].ItemArray[];
            var arrlist2 = s1[].ItemArray[];
            var arrlist3 = s1[].ItemArray[];
            var arrlist4 = s1[].ItemArray[];
            Console.WriteLine(arrlist1);
            Console.WriteLine(arrlist2);
            Console.WriteLine(arrlist3);
            Console.WriteLine(arrlist4);
            //单条查询
            //SqlDataReader dataAdapter = Command.ExecuteReader();
            //while (dataAdapter.Read())
            //{
            //    Console.WriteLine("{0}", dataAdapter["FieldName"]);
            //}
            Console.ReadKey();
        }
        //改
        public void AdoEdit(string cmd)
        {
            Conn.Open();
            using (SqlCommand sqlcmd=new SqlCommand(cmd,Conn))
            {
                sqlcmd.CommandText = cmd;
                if (sqlcmd.ExecuteNonQuery() > )
                {
                    Console.WriteLine("修改成功");
                }
                else
                {
                    Console.WriteLine("修改失败");
                }
            }
        }
 
    }

在控制台入口声明sql语句  调用增删查改的方法

 static void Main(string[] args)
        {
            //sql连接字符串
            var  adoNet = new AdoNet(".","Ttest","sa","");
            ////调用查询方法
            //var sqlstr = "select * from Field";
            //adoNet.AdoNetState(sqlstr);
            //增加
            //string strsql = "insert into Field(FieldName)values('哈哈哈')";
            //adoNet.AdonetAdd(strsql);
            //删除
           // string strsql = "delete from Field where FieldName='哈哈哈'";
            //adoNet.AdoDelete(strsql);
            //修改
            string strsql = "Update Field set FieldName='Lisa' where FieldName='meiName'";
            adoNet.AdoEdit(strsql);
        }