ADO.net 基础

 1 using System.Data.SqlClient; //数据库连接命名空间 2 ?3 namespace ado.net1 4 { 5 ????class Program 6 ????{ 7 ????????static void Main(string[] args) 8 ????????{ 9 ????????????//连接字符串10 ????????????string ConnectionString = "server=.;database=Data0908;user=sa;pwd=123;";11 12 ????????????//数据库连接类13 ????????????SqlConnection conn = new SqlConnection(ConnectionString);14 15 ????????????//数据库操作类16 ????????????SqlCommand cmd = conn.CreateCommand();// 操作类不能实例化对象，要通过连接类对象的方法来创建操作类17 18 ????????????//要执行的tsql语句19 ?????????????cmd.CommandText = "insert into Users values(‘xiaohua‘,‘1234‘,‘小花‘,‘False‘,‘2004-4-4‘,‘N004‘)"; //增数据 一次只能执行一句 ，一行一行的加！！20 ????????????//cmd.CommandText = "update Users set NickName = ‘张三三‘ where UserName = ‘zhangsan‘"; //改数据21 ????????????//cmd.CommandText = "delete from Users where username = ‘zhangsan‘"; //删数据22 23 ????????????//开启数据库连接24 ????????????conn.Open();25 26 ????????????//执行语句，！！！此方法只负责增删改的操作27 ????????????int a = cmd.ExecuteNonQuery();//返回的是受影响的行数28 29 ????????????//关闭数据库连接30 ????????????conn.Close();31 ???????????//同过判断 a 的值来判断是否增删成功32 ????????????if (a > 0) Console.WriteLine("执行成功");33 ????????????else Console.WriteLine("失败");34 35 ????????????Console.ReadKey();36 ????????}37 ????}38 }

 1 namespace ado.net查 2 { 3 ????class Program 4 ????{ 5 ????????static void Main(string[] args) 6 ????????{ 7 ????????????string connstr = "server=.;database=Data0908;user=sa;pwd=123;"; 8 ?9 ????????????SqlConnection conn = new SqlConnection(connstr);10 11 ????????????SqlCommand cmd = conn.CreateCommand();12 13 ????????????cmd.CommandText = "select *from Users";14 15 ????????????conn.Open();16 17 ????????????//创建数据读取对象 ?这个地方和增删改区别18 ????????????SqlDataReader dr = cmd.ExecuteReader();19 20 ????????????if (dr.HasRows) //如果读到了行数据 这是个bool类型 判断是否有数据可读21 ????????????{22 ????????????????while (dr.Read()) //一行一行读取 这也是个bool类 有数据就读 没数据就在原地不动23 ????????????????{24 ????????????????????Console.Write(dr["UserName"]); //获取每一行的每一个字段的值25 ????????????????????Console.Write(" | "); //分割线26 ????????????????????Console.Write(dr["PassWord"]);27 ????????????????????Console.Write(" | ");28 ????????????????????Console.Write(dr["NickName"]);29 ????????????????????Console.Write(" | ");30 ????????????????????Console.Write(dr["Sex"]);31 ????????????????????Console.Write(" | ");32 ????????????????????Console.Write(dr["Birthday"]);33 ????????????????????Console.Write(" | ");34 ????????????????????Console.Write(dr["NationCode"]);35 ????????????????????Console.Write(" | ");36 ????????????????????Console.WriteLine(); //换行37 ????????????????}38 ????????????}39 40 ????????????conn.Close();41 42 ????????????Console.ReadLine();43 ????????}44 ????}45 }